HISTORY
The name Prostaglandins (PG) is derived from the
prostate gland from where when PG was 1st
isolated from seminal fluid in 1936.
The biochemists -
Sune K. Bergstrom
-
Bengt I. Samuelsson
-
John R. Vane
Jointly received the 1982 Nobel Prize in physiology or medicine for their
research in PGs in Sweden.
They were honoured for their isolation, identifications and analysis of
numerous PGs, a family of natural compounds that can
influence blood pressure, body temperature, allergic
reaction and other physiological phenomena.
Bergstrom:
He has purified several PGs & determine their chemical
structure.
He showed that PG is formed from unsaturated fatty
acid.
Bengt Samuelsson :
He has given a detailed picture of arachidonic acid & PG metabolism. And
also clarified the chemical process involved in
formation & breakdown of the various compounds in the
system.
He also presented understanding of biological significance of this system
by discovering endoperoxides, thromboxanes &
leucotrines.
John Vane :
Discovered prostacyclin & carried out detailed analyses of its biological
effects & function.
Anti inflammatory compounds such as aspirin act by blocking the formation
of PGs & thromboxanes.
BIOCHEMISTRY
Prostaglandins are C-20 carboxylic acids containing
cyclopentane ring and are derivatives of prostanic acid.
In 1970 14 natural prostaglandins were known, with the help of efficient
and sensitive analytical techniques, hundreds of these
compounds have been described.
The nomenclature of PGs is based on :
-
The letter component (PGA, PGB, PGC) which identities
the functional groups of the cyclopentane ring.
-
PG Es contain a keto oxygen at C-9 and a hydroxyl group
at C-17, where as PG Fs have hydroxyl group at both
positions in the cyclopentane ring.
-
Numerical subscript (PGE1, PGE2) denotes number of
double bond in carbon chain this number depends on the
precursor Fatty acid.

Prostaglandins E and F series are synthesized from arachidonic acid [C20
Fatty acid]. Free archidonic acid is required for PG
synthesis. Liberation of arachidonate from phospholipids
by phospholipases is the rate limiting step in cascade
of synthesis.
This endoperoxide synthetase catalyzes the sequential formation of PGG2 &
PGH2 (endoperoxides) by addition of molecular oxygen
at the C9, C11 & C15 position.

PGH2 is enzymatically (endoperoxide isomerase, endoperoxide reductase) &
nonenzymatically converted in several molecules,
which are biologically active & also are precursors
of other active molecule.
These PGs are PGD2 which is principal cyclo oxygenase product of mast
cells & nervous system, PGE2 produced nearly in all
cells, PGF2, PGI2, TXA, 12 HHT (12- hydroxyheptadeca
-5,8,10 – trienoic acid).
Prostaglandin of A & B series produced from PG E series & TXB2 (stable but
biologically inactive) formed from TXA2.
??
Dietary Sources of Prostaglandins
??
Rich Sources
Sunflower Seed
Sesame
Cotton Seed oil
??
Good Sources
Mustard
Ground Nut Oil
Egg Yolk
??
Poor Source
Butter
Coconut Oil
PHARMACOLOGY OF
PROSTAGLANDINS
-
Chemically, prostaglandins may be considered
to be derivatives of prostanoic acid (a
cyclopentane / pentene ring with two side
chains).
-
PGs are broadly classified as PGA – PGH
based on their cyclopentane / pentene ring
substitution patterns.
-
Each general PG class has members with
subscript 1, 2, and 3 indicating the number
of double bonds in the side chain.
-
Leukotrienes are so named because they were
first obtained from leucocytes and have 3
conjugated double bonds (Triene). They have
also been similarly designated A, B, C……F
and given subscripts 1, 2, 3, 4.
-
In the body prostaglandins, thromboxanes and
leukotrienes are all derived from eicosa
(referring to 20 carbon atoms)
tri/tetra/pentaenoic acids. Therefore they
can be collectively called eicosanoids.
-
The key precursor in eicosanoid biosynthetic
pathways is arachidonic acid. Cells store
arachidonic acid as a component of membrane
phospholipids such as phosphoinositol. In
response to appropriate stimulus,
arachidonic acid is liberated from the
storage lipid by an enzymatic reaction
catalyzed by phospholipase A2. The
conversion of free arachidonic acid to
prostaglandins and other eicosanoids is
initiated by oxidative enzymes of the
cyclooxygenase and lipooxygenase families.
INHIBITION OF SYNTHESIS
-
Glucocorticoids inhibit the release of
arachidonic acid from membrane lipids by
stimulating production of proteins
called lipocortins which inhibit
phospholipase A2.
-
Moreover they inhibit the induction of
COX-2 by cytokines at the site of
inflammation.
-
Cyclooxygenase enzyme exists in two
isoforms COX-1 and COX-2, cox-1 is
constitutive while cox-2 can be detected
is significant amounts only during an
inflammatory response.
-
Synthesis of cyclooxygenase products can
be inhibited by NSAIDs.
-
Aspirin causes irreversible inhibition
while other NSAIDs are competitive and
reversible inhibitors.
-
Most NSAIDs are nonselective cox-I and
cox-2 inhibitors but some newer ones
like celecoxib, rofecoxib are selective
for COX-2.
-
NSAIDs do not inhibit the production of
leucotrienes; this may even be increased
since all the arachidonic acid becomes
available to the lipooxygenase pathway.
DEGRADATION
-
Degradation of arachidonates occurs
rapidly in most tissues but fastest in
the lungs.
-
Most PGs, TXA2 and prostacyclin have
plasma t?? of few seconds to
few minutes.
-
Metabolites are excreted in urine.
-
PGI2 is catabolized mainly in
the kidney.
PHYSIOLOGIC ACTIONS OF ELCOSANOIDS
-
The PGs are important mediators of
normal physiologic events and have been
implicated in a variety of pathologies.
-
They have been implicated in
inflammation, pain, pyrexia,
cardiovascular disease, renal disease,
cancer, glaucoma allergic rhinitis,
asthma, preterm labour, male sexual
dysfunction and osteoporosis.
-
Prostaglandin effects are usually
manifested locally around the site of
prostaglandin synthesis (paracrine) and
their actions are multiple and variable
(stimulatory or inhibitory) depending
upon the tissue type and the nature of
the receptors with which they interact.
1)
Cardiovascular System
PGI2
- Vasodilatory action
- Hypotension
TXA2
- Vasoconstriction
Leucotrienes
- ?? capillary permeability
LTB4
- Chemotactic for neutrophils and
macrocytes
Role: PGE2 and PGI2 are continuously
produced locally in the ductus arterious
during fetal life – to keep it patent.
At birth their synthesis is inhibited
and closure occurs. Aspirin and
Indomethacin has been found to induce
closure when it fails to occur
spontaneously.
Leukotrienes – are important mediators
of inflammation LTC4 & D4 – exudation of
plasma.
LTB4 – attracts inflammatory cells which
reinforce the reaction.
2)
Platelets
TXA2 – (+) Platelet aggregation
PGI2 – (-) platelet aggregation
Role: TXA2 and PGI2 constitute a
mutually antagonistic system; preventing
aggregation of platelets while in
circulation and inducing aggregation on
injury when plugging and thrombosis are
needed.
In low doses, aspirin selectively
inhibits TXA2
production and has antithrombotic effect
lasting >3 days.
3)
Bronchial Muscle
PGF2a, PGD2 AND TXA2 –
bronchoconstrictors
PGE2 – bronchodilator
LTC4 and D4 – most important mediators
of human allergic asthma
4)
Uterus
PGE2 and PGF2a
contract human uterus.
Sensitivity ?? during pregnancy and there
is a further modest ?? with the progress
of pregnancy.
PG’s increase tone as well as amplitude
of uterine contractions at term. PGs at
low doses soften the cervix and make it
more compliant.
Role: (1) Fetal tissues produce PGs at
term and it has been postulated that PGs
mediate initiation and progression of labour Aspirin has been found to delay
the initiation of labour and also
prolongs its duration.
Dysmenorrhoea in many women is
associated with increased PG synthesis
by the endometrium.
?? PG’s
??
incoordinated uterine contractions
??
compression of blood vessels
??
uterine ischemia
??
pain
Aspirin group of drugs are highly
effective in relieving dysmenorrhoea in
most women.
5)
GIT
-
?? propulsive activity by PGE2 ?? colic
and watery diarrhea
-
PGs appear to play a role in the growth
of colonic polyps and cancer
\ Regular intake of aspirin ?? ??
incidence of colon cancer
-
PGE2 ?? reduces acid secretion in the
stomach. Secretion of mucus in stomach
and mucosal blood flow are increased –
antiulcerogenic.
-
Ulcerogenic action of NSAIDs may be due
to loss of this protective influence.
-
PGs are involved in mediating toxin
induced increased fluid movement in
secretory diarrheas.
USE OF PROSTAGLANDINS IN
OBSTETRICS
2ND TRIMESTER MTP WITH
MEDICAL METHODS
Introduction
Termination of pregnancy beyond 12 weeks of gestation to 20 weeks
Indication: - IUFD
- Missed abortion evacuation
- Hydatidiform mole evacuation
- Congenital anomaly
MEDICAL ABORTION TEACHNIQUE
Agent used
:
Misoprostol
Intramuscular Prostaglandin E2 PGF2 a
(Carboprost)
Misoprostol:
Methyl – 11x, 16 dihydroxy -16 methyl
9.0 x O Prost
13 E-on-loate
??
Prostaglandin E1 analogues binds
with myometrial cells cause strong
myometrial contraction.
??
Cause cervical ripening and
softening and dilatation of cervix.
??
Molecular formula
C22H38O5

??
Characteristics :
??
It limits extent of
gastrointestinal damage induced by
ulcerogenic agents.
??
It has uterotonic and cervical
ripening actions.
??
After oral administration,
misoprostol is rapidly absorbed and
converted to its pharmacologically
active metabolite misoprostol acid.
??
After oral administration of
misoprostol, plasma level of misoprostol
acid reaches to peak in 30 minutes and
declines rapidly thereafter.
??
When misoprostol tablets are
placed in the posterior fornix of the
vagina, plasma concentration of
misoprostol acid reaches to peak in one
or two hours and then decline slowly.
??
The bio-availability of
misoprostol is decreased by concomitant
ingestion of food or antacids.
??
Half life of misoprostol is 20-40
minutes.
??
Duration of action, 3-6 hours.
??
Metabolism.
Misoprostol is primarily metabolized in
the liver and less than
1% of its active metabolite is excreted
in urine.
??
Uterine contractility is
initially increased and then plateaued
one hour after oral administration where
as uterine contractility is increased
continuously for four hours after
vaginal administration.
Thus, the effects of misoprostol on the reproductive tract are increased
and gastrointestinal adverse effects are
decreased, if the oral preparation of
misoprostol is administered vaginally.
??
Supply
It is available as Misoprost and cytotec
tab, with the strength of 100/200
microgram misoprostol.
Regime @ mifepristone rooms F16
misoprostol
Route
: Orally, vaginally
Mechanism
of action : Uterine
muscle contractility ??es and has
uterotonic & cervical ripening action.
Doses
: 200 mcg kept in posterior
fornix every 6 hourly.
Regime : -
Misoprostol 400 mcg 6 hourly.
- Mifepristone 200
mcg follow by misoprostol 400
mcg
per vaginally
Indications:
1)
Treatment of gastric, duodenal ulcer,
NSAID induced ulcers.
2)
Prophylactic for NSAID induced ulcers.
3)
For induction and augmentation of
abortion.
4)
For induction and augmentation of
labour.
5)
For prevention & treatment of
post-partum hemorrhage.
6)
For induction & augmentation of 1st
and 2nd trimester termination
of pregnancy.
Contraindications:
1)
Previous cesarean section
2)
Past hysterotomy or surgery
3)
Classical upper segment cesarean
section.
CARBO PROST PGF2a
Intramuscularly given (200-300 ug) 2 to 4 hourly.
Mechanism of action:
1)
Stimulate uterus
??es uterine contractility ??es smooth
muscle contraction.
2)
??es tubal motility
3)
??es systemic arterial and venous
pressure ??es regional arterial flow.
Route of Administration
- intra muscular
- vaginal administration
Contraindication
-
Hypersensitivity to any of component
-
Acute PID
-
Cardiac diseases
-
Pulmonary diseases
-
Renal disease
-
Liver diseases
-
Glaucoma
DOSES:
Carboprost 200-300 ug 2 to 4 hourly.
DISADVANTAGE OF PROSTAGLANDINS
-
Costlier drug
-
Fetus may be aborted alive
-
Abortion quicker hemorrhage and cervical
laceration may occur.
ADVANTAGE OF MEDICAL METHOD
-
Usually avoid invasive procedure
-
High 54 case rate (95%)
-
Avoids anesthesia
-
Available during early pregnancy
-
Can be done where surgical methods are
contraindicated.
Disadvantage
-
Require follow up to ensure complete
procedure
-
Patient participation through a multiple
step process
-
Require two or more visits
MEDICAL ABORTION
PROCEDURE:
Early pregnancy termination usually b/w
42 to 63 days performed without primary
surgical intervention and resulting from
the use of abortion inducing
medications.
Mechanism of action
=> Mifepristone (RU 486) used
orally,
Mechanism of action: Mifepristone has
affinity for progesterone receptor 5
times higher than progesterone thus
causes choriodecidual separation by
initiating breakdown of endometrium &
detachment of embryo (leads to decline
of b-HCG & atrophy of corpus luteum and
also decline S. progesterone level ??
initiate myometrial contraction.
??
Expulsion of embryo.
Mifepristone alone is not effective
should be followed by prostaglandin
analogue.
Mifepristone also ??es uterine
sensitivity to PGs thus ??es its release.
=>
Misoprostol PGE1 => Synthetic analogue
of naturally occurring PGs.
Adv.
Safe, well tolerated, can be kept at
room temperature etc.
Can be used Orally ?? GI side effects more
Vaginally ?? GI side effects less
??
slower ??es & low peak plasma
concentration then oral
But uterine contractility ??es and then plateau one hour after oral
administration, whereas contractility
continues for four hour after vaginal
route.
PROTOCOL FOR MEDICAL ABORTION
1)
History
2)
Exclude contraindication
3)
Clinical Examination to exclude
cervicovaginal pathology.
4)
Accurate dating including TVS
5)
Hb & BG estimation
6)
Back up surgical facility should be
available.
Currently available drugs for medical abortion:
1)
Mifepristone (RU 486) => Antiprogestin
2)
Methotrexate => Antimetabolite
3)
Tamoxifen : All above drugs to be
followed by intravaginal misoprostol
4)
Misoprostol alone (Most commonly used
prostaglandin analogue)
REGIMENS:
1)
Commonly used: Mifepristone orally
200-600 mcg on day 1.
??Followed by
400 to 800 ug misoprostol intravaginally
on 3rd
day.
??
Observation for 1 to 3 hr.
Follow up after 2 wks by P/v examination
and TVS SOS and again after 6 wks or
after 1st
post abortal period. Effectiveness
94%
In oral misoprostol.
Effectiveness 87%
2)
Methotrexate => 50 mcg/m2
IM on day 1
?? Followed by
400-800 ug misoprostol intravaginally.
Effectiveness 89 to 98%
3)
Tamoxifen : 20 mg 1 OD x 4 days
Followed by
400-800 ug misoprostol intravaginally
4)
Misoprostol alone:
400 ug intravaginally every 6 hourly. OR
200 ug intravaginally every 4 hourly.
Effectiveness 30%
Contraindications
-
Allergy
-
Asthma
-
Anticoagulant therapy
-
Hemorrhagic disorder
-
Smoker, > 35 yrs.
Advantages over surgical procedure:
1)
??es risk of cervical &
intrauterine injury
2)
Infection chances less
3)
More natural do not require operating
room.
Disadvantages:
1)
Takes longer times to abort
2)
Longer duration of bleeding
3)
Cost
4)
Compliance of patient
5)
Repeated follow up
6)
Teratogenic effects on fetus in c/o
failure of medical abortion e.g. Mobius
syndrome - congenital facial paralysis
with or without limb defect, cranial
nerve defect.
Other Regimes
If amenorrhea 7 – 14 days on day 1st
mifepristone 200 mcg orally
?? followed by 48 hr later
5 mg PGE2 vaginal gel (metenoprost)
Effectiveness 94.5%
If amenorrhorea < 6 wks Tab mifepristone 600 mcg
?? followed by after 48 hrs
Intravaginally 100 ug of misoprostol
Effectiveness 97.37%
-
Majority of cases bleeding occurs with
in 4 hr. & bleeding continues for median
10 days.
-
Total blood loss similar to / related to
gestational age.
-
Heavy bleeding can occur in less than 1%
cases.
PROSTAGLANDINS FOR
CERVICAL RIPENING & INDUCTION
INTRODUCTION
In pregnancy, the uterine cervix serves 2 major functions. First, it
maintains its firmness during pregnancy
as the uterus dramatically enlarges.
This physical integrity is critical so
that the developing fetus can remain in
the uterus until the appropriate time
for delivery. Second in preparation for
labour and delivery, the cervix softens
and becomes more distensible, a process
called cervical ripening.
CERVICAL CHARACTERISTICS
-
The human cervix consists mainly of
extracellular connective tissue. The
predominant molecules of this
extracellular matrix are type I and type
3 collagen, with a small amount of type
4 collagen at the basement membrane.
-
Intercalated among the collagen
molecules are glycosaminoglycans and
proteoglycans, predominantly dermatan
sulfate, hyaluronic acid and heparin
sulfate. Fibronectin and elastin also
run among the collagen fibers. The
highest ratio of elastin to collagen is
at the internal os. Both elastin and
smooth muscles decrease from the
internal to the external os of the
cervix.
-
Cervical ripening usually begins prior
to the onset of labour contractions and
is necessary for cervical dilatation and
passage of the fetus.
-
Cervical ripening is the result of a
series of complex biochemical processes
that ends with rearrangement and
realignment of the collagen molecules,
degradation of collagen cross-linking
due to proteolytic enzymes and
dilatation resulting from these
processes plus uterine contractions.
-
In late pregnancy, hyaluronic acid
content increases in the cervix. This
leads to an increase in water molecules
that intercalate among the collagen
fibers. The amount of dermatan sulfate
decreases which leads to reduced
bridging among the collagen fibers and
thus a decrease in cervical firmness. ??
activity of metalloproteinases 2 & 9
degrade extra-cellular matrix protein
with leads to ?? collagen content in the
Cervix.
-
Cervical ripening is associated with
decreased collagen fiber alignment,
decreased collagen fiber strength and
diminished tensile strength of the
extra-cellular cervical matrix.
-
All of these changes cause cervical
softening. With uterine, contractions,
the ripened cervix dilates and is pulled
over the presenting fetal part. Elastin
component of cervix behaves in a ratchet
like manner so that dilatation is
maintained following the contraction.
ROLE OF VARIOUS HORMONES IN THE PROCESS OF CERVICAL RIPENING
-
A complex series of interactions occurs
whereby various hormones stimulate the
chemical reactions critical for cervical
ripening.
-
Associated with cervical ripening is an
increase in enzyme cyclooxygenase – 2
which leads to a local ?? of PGE2 in the
cervix. The increase in local PGE2 leads
to the following changes associated with
cervical ripening
o
Dilatation of small vessels in
the cervix
o
Increase in collagen degradation
o
Increase in hyaluronic acid
o
Increase in chemotaxis for
leucocytes, which causes increased
collagen degradation.
o
Increase in stimulation of IL-8
release.
-
PGF2a
is also involved in the process via its
ability to stimulate an increase in
glycosaminoglycans.
-
The role of inflammatory agents in
cervical ripening has also been studied
IL-I, TNF & IL-8 can lead to neutrophil
chemotaxis which is associated with
collagenase activity and cervical
ripening. These inflammatory agents may
be particularly important as mediators
of cervical ripening associated with
preterm labour.
-
Nitric acid appears to play a role in
this process by leading to an increase
in metalloproteinase activity, cellular
apoptosis in the cervix and
glycosaminoglycan synthesis in the
cervix. All of these changes are
associated with the cervical ripening
process. Nitric oxide could also play a
role in premature cervical ripening
associated with preterm labour,
particularly in preterm labour triggered
by infection.
EVALUATION OF CERVICAL RIPENING
1)
BISHOP SCORE :
a) Dilatation
0 cm
- 0 points
1-2 cm
- 1 point
3-4 cm
- 2 points
5-6 cm
- 3 points
b) Effacement
0-30 %
- 0 points
40-50%
- 1 point
60-70%
- 2 points
80 %
- 3 points
c) Station
-3 station
- 0 points
-2 station
- 1 points
1 & 0 station
- 2 points
+1 to +2 station
- 3 points
d) Consistency
Firm
- 0 points
Medium
- 1 point
Soft
- 2 points
Posterior position
- 0 points
Mid position
- 1 point
Anterior position
- 2 points
2)
ULTRASOUND ASSESSMENT
-
Helps to determine the length of cervix
-
Helps to determine the presence or
absence of cervical funneling.
-
Prior to 20 weeks of pregnancy, a
cervical length of less than 21 mm is
highly predictive of preterm labour and
delivery.
3)
DETECTION OF FETAL FIBRONECTIN IN
CERVICOVAGINAL
-
Fetal fibronectin is a glycoprotein
found in amniotic fluid and at the
chorionic decidual interface. The
presence of this protein in
cervicovaginal secretions predicts
preterm labour while its absence
predicts prolongation of pregnancy.
-
Fetal fibronectin is also predictive of
response to prostaglandin application to
the cervix at term in order to induce
cervical ripening and labour.
PROSTAGLANDINS FOR
INDUCTION OF CERVICAL RIPENING
PGE2 (Dinoprostone)
a)
Prepidil 0.5 mg gel (for intracervical
use)
b)
Cervidil – 10 mg dinoprostone embedded
in a mesh to be placed in posterior
fornix of the vagina. This allows for
controlled release of dinoprostone over
12 hrs.
Advantage of cervidil vaginal insert is that it can be removed if
hyperstimualtion occurs.
The intracervical route offers the advantages of prompting less uterine
activity and greater efficacy in a woman
with very unripe cervix.
Patient selection: Bishop score of 4
or less.
Administration:
The woman remains recumbent for atleast 30 minutes following application.
The woman and fetus must be monitored
for contractions, fetal well being and
changes in cervical Bishop score
Side Effects:
1)
Uterine hyperstimulation – 6 or more
contractions in 10 minutes for a total
of 20 minutes.
2)
Should not be used in patients with
glaucoma, severe hepatic or renal
impairment and asthma.
PROSTAGLANDIN E1 (MISOPROSTOL)
Vaginal misoprostol
-
25 ug misoprostol to be kept in
posterior fornix every 3 to 6
hourly.Such usage decreases the need for
oxytocin, achieve higher rates of
vaginal delivery within 24 hours of
induction and significantly reduce
induction – delivery intervals.
-
50 ug Misoprostol
- ?? Tachysystole
- Meconium passage
- Meconium aspiration
- ?? rate of cesarean delivery
- 25 ug
misoprostol is associated with fewer
side effects than the 50 ug dose.
ORAL MISOPROSTOL
Oral and Vaginal applications of misoprostol have similar efficacy for
cervical ripening and labour induction
but an oral dosage of 200 ug was
associated with more frequent abnormal
uterine contractility.
PROSTAGLANDINS FOR
INDUCTION OF LABOUR IN SPECIAL
SITUATIONS
1)
Pregnancy with Heart disease
Cardiac disease it self is not an
indication for labour induction. But
induction should not be withheld if it
is necessary for obstetric reasons.
Induction at labour may also be
suitable, for patient with prosthetic
valves, who have transferred from
warfarin to heparin as this will
minimize the period without warfarin.
PGE2 can be used for
induction: PGE2 is potent vasodilator &
causes a marked rise in cardiac output.
In high doses when used, has caused
cardiac arrest even in normal patients.
Minimum dose should be used & prolonged
treatment should not be attempted. A
study was conducted by Rush RW Mabin 7,
in which 4 mg of PGE2 tablet was used
per vaginally for heart disease patient
for induction at labour when indicated.
84% patient went into labour & delivered
within 24 hrs. 90% at them delivered
vaginally. None of them developed
deterioration in cardiac status.
2)
Women with cesarean section scar :
There is an increasing incidence of
multipara presenting in pregnancy with a
history of delivery by lower segment
cesarean section. In consequence there
is greater need to consider how best to
manage subsequent confinements.
A major concern of women attempting VBAC
is uterine rupture, the frequency of
which varies with the type of cesarean
section.
Type of
incision |
Incidence of
rupture (%) |
Low
transverse
Low vertical
Classical
vertical |
0.2 – 1.5%
1 – 7%
4 – 9% |
There is a dearth of evidence from which
to assess the risks and benefits of
using prostaglandins to induce labour in
women with a scar from previous LSCS.
While it is difficult for clinicians to
find and assimilate the evidence it is
important to remember that the woman is
also participant in the decision making
process. For some women the shorter
recovery time & feeling satisfaction if
a vaginal delivery is achieved would be
important factor in favour of inducing
labour. For others, the convenience &
feeling of being in control,
apprehension of the possibility of
failed trial of labour f/b an emergency
section may make an elective cesarean
section preferable to induction. A
summary of 10 studies found that there
is no statistical difference in scar
disruption rate between PG E2 group
(1.60%) & spontaneous labour group
(1.23%).
In one large prospective study
(Mackenzie et al) of 143 patients with
previous LSCS whose labour was induced
using vaginal PGE2: 68% patients with an
unfavourable cervix delivered vaginally
& it increase to 89% with favourable
cervix. In none did the lower segment
scar rupture. But misoprostol does not
appear to be safe for induction in
patients with scared uterus. Different
studies had shown high frequency of
disruption of prior uterine incision
(3.5 – 5.6%) scar.
Study |
Uterine
rupture per study group
Induction with misoprostol |
Spontaneous
delivery |
Plant et al
(1999)
Cunha et al
(1999)
Butt et al
(1999) |
5/89
2/57
3/37 |
0/364
0/57
13/560 |
TOTAL |
10/285
(3.5%) |
13/1069
(1.1%) |
It women with previous lower segment
scar are induced with prostaglandins
using preparation & regimen suggested by
Mackenzie risk of symptomatic scar
rupture seems to be no greater than the
rate quoted for spontaneous labour in
women with a cesarean scar. At present,
faced with the lack of comparative
evidence, clinicians can only provide
women with the best estimate of risk
based on uncontrolled observational
data.
3)
IUFD
An Intrauterine fetal death is a
catastrophic incident. The diagnosis
itself heralds the fact that it is too
late to intervene. What is left to
obstetrician often falls under the
domain of damage limitation.
A spontaneous labour usually ensues
within few weeks of a failed pregnancy.
However due to the psychological effect
on mother, to prevent complication and
to overcome the uncertainty of
spontaneous labour, induction of labour
is usually done in a case of IUFD.
Prostaglandins E & F and their various
analogues have been used via different
routes for induction of labour in case
of IUFD.
PGE2: Dinoprostone (oral tablets,
vaginal gel) may be used. 15 methyl PGF2a
can be administered by I/M,
extraamniotic or extra amniotic route
Gemeprost (PGE1) 1 gm pessaries can be
used vaginally at 3 hourly interval for
a maximum of 5 doses course may be
repeated after an interval of 24 hrs.
But they are expensive, thermolabile &
require refrigeration”. Sulprostone :
synthetic derivative of PGE2 may be used
1/M or I/V. Anaphylactic reaction &
severe hypotension can occur.
Misoprostol: Synthetic PGE1 analogue
tablets are inexpensive, can be stored
at room temperature can be used orally
or vaginally. Randomized study from
Thailand compared effectiveness & side
effects of oral & vaginal misoprostol
for termination of pregnancy with IUFD.
They concluded that oral misoprostol 400
ug every 4 hourly was more effective
than vaginal misoprostol 200 ug/ 12
hourly. A quicker uterine response is
found in mothers with advanced gestation
(> 34 wk) & higher Bishop score (>5).
4)
PROM :
I.e. rupture of membrane before the
onset of labour Incidence is 6-19%.
When the fetal membranes rupture
spontaneously around term, labour
generally establishes within few hours.
(86% go into labour within 24 hrs.) when
there is delay in onset of labour, there
are concerns of intrauterine infection
developing and many obstetricians favour
stimulating contractions with an
Oxytocics. Prostaglandins have been used
for this purpose in variety of ways.
Many trials have compared the obstetric
outcome that follows stimulation of
labour with prostaglandin as opposed to
oxytocin in PROM at term. Metaanalysis
of such trials shows a tendency for
reduced cesarean section rate with use
of prostaglandins, decrease rate of
maternal infection & neonatal intensive
care unit admission. Prostaglandins
appear to be safe in stimulating labour
when membranes have ruptured & appear to
be safe whichever administration route
is used.
One randomized control study compared
expectant management, oxytocin & PGE2
vaginal tablet for cervical ripening &
induction in patients with PROM with
unfavourable cervix. The results of this
study have shown that PG induction is
the method of choice in such patients.
PGE2, E1 can be used either vaginally or
orally with varying doses without any
significant difference in outcome.
Misoprostol is used with dose ranging
from 25-200 ug. Increasing the dose of
misoprostol to more than 25-50 ug may
lead to faster deliveries but also to
more unpredictable or uncontrollable
uterine stimulation.
Post term Pregnancy
Pregnancy beyond 294 days from 1st
day of last menstrual period. Incidence
varies from 3-10%. Women with
uncomplicated pregnancy beyond 41 wks
should be offered induction.
Recent metaanalysis of 13 controlled
trials, where induction of labour for
prolonged pregnancy was compared with
intention to await spontaneous labour,
showed small but a statistically
significant reduction in the likelihood
of delivery by caesarean section when
labour was induced at 41 wk 3 day. The
risk of perinatal death was reduced in
the induction group. Either PGE2 or E1
can be used for induction.
Rate of C.S. for failed induction
depends upon parity & cervical score.
C.S. rate for failed induction according
to parity & cervical score :
Cervical
Score |
Para O |
Para 1
< |
n |
% |
n |
% |
0-3
4-6
10 |
27/59
30/292
3/208 |
45.8
10.3
1.4 |
2/26
10/257
2/215 |
7.7
3.9
09 |
The incidence of cesarean section for
failed induction in nullipara with poor
cervical score was low with PGs.
Indication for C.S. in nulliparae with a
poor cervical score :
Treatment
regimen Indication
|
Oxytocin &
Amniotomy
|
Prostaglandins |
N=230 |
% |
N=152 |
% |
Fetal
distress
CPD or
molposition
Failed
induction
Others |
27
10
55
8 |
11.4
4.4
23.9
3.5 |
13
8
14
1 |
8.6
5.3
9.2
0.7 |
TOTAL |
100 |
43.5 |
36 |
23.7 |
P< 0.001
PGs CAUSING PIH
Prostaglandin H Synthetase (PGHS) is a rate liming enzyme in the
production of PGs and thromboxane which
are important regulator of vascular
function.
Under normal physiological condition
PGHS dependant vasodilators such as
prostacyclin modulate the vascular tone,
while PGHS dependent vasoconstriction
which is mediated by thromboxane A2 &
PGH2, predominant in some
vascular pathology like HT, DM, cerebral
ischemia.
Prostaglandin H synthetase pathway
Superoxide anions are released by
activity of PGHS
(1)
These anions can initiate the
membrane lipid peroxidation which
leads to
??ed production of TXA2
?? vasoconstriction.
(2)
Superoxide anions also react with
Nitric oxide to form, Peroxi nitrite
thus reduce nitric oxide
bioavailability
???? vasodilation
(3)
Superoxide anions also produced
isoprostants which further
??es the PGHS activity.
(4)
Due to extensive lipid peroxidation,
peroxi nitrite
???? production of PGI2 ????
vaso relaxation.
All
these pathways collectively may
represent the mechanism for balance
b/w relaxing & contracting factor
there by contributing to vascular
dysfunction.
PGHS : -
It is a 69 KDA protein
- Present in
endothelium and smooth muscle cells
-
Concentration of PGHS is 20 times
more in endothelium than smooth
muscle cells
- Mainly
present in luminal surface of
endoplasmic reticulum.
- Mainly ??es
in oxidative stress, dyslipidemia,
heart diseases, obesity
- Also
derived from platelet.
In pre-eclampsia ?? PGHS activity
increases
??
?? TXA2 activity than PGI2
In pre eclampsia patient there is ?? activity of PGHS in
placental trophoblast.
??
Which alter fetoplacental function and also ??es thromboxane
receptor in vasculature which also
leads to IUGR
Low dose of aspirin used to inhibit platelet derived PGHS in pregnant
women to prevent pre eclampsia.
ANTIPROSTAGLANDINS
FOR TREATMENT OF PIH
-
Preeclampsia is associated with
vasoconstriction and microthrombosis
in the mother and can lead to IUGR
and fetal death.
-
The evidence of activation of the
clotting system and the imbalance of
the prastanoids ratio in
pre-eclampsia and IUGR with early
platelet involvement suggested the
use of antiplatelet agents (usually
low dose aspirin) to prevent or
relieve the condition.
-
The pharmacological basis for
preventing pre-eclampsia with
aspirin is that aspirin in low doses
selectively inhibits cyclo oxygenase
activity in platelets but not in the
endothelium thereby suppressing the
synthesis of platelet TXA2, without
effecting the production of vascular
prostacyclin.
-
The reason for this selective
inhibition lies in the fact that
platelets being anucleated cells
have a limited life span (8-11 days)
and cannot synthesise new
cyclooxygenase. Therefore once
platelet cyclooxygenase is
inhibited, its activity will be
suppressed for the platelet’s life
span and recovery will occur only
when unaffected platelets are
produced. On the other hand,
endothelial cells do have a nucleus
so they can resynthesise cyclo
oxygenase after inhibition by ASA.
-
The biochemical selectivity of low
dose aspirin may be related to its
unusual kinetics. Aspirin is quickly
absorbed in the small intestine and
is rapidly metabolized by the liver
(first pass effect), allowing
unrecordably low plasma
concentrations in the post systemic
circulation.
Aspirin in such doses acetylates the
cyclooxygenase in platelets in the
prehepatic circulation whereas very
little drug reaches the systemic
vascular endothelium and
uteroplacental circulation and thus
has a little influence on the
production of prostacyclin. This
significantly improves prostacyclin
/ TXA2 ratio.
-
Low dose aspirin selectively and
significantly reduces TXA2
production by total platelet and
placenta of women with pre-eclampsia
without affecting PGI2 production by
human placental arteries. This
selective inhibition could be
possible because fetal platelet
cycloxygenase was 4.44 times more
sensitive to aspirin than umbilical
artery cyclooxygenase.
-
Pre-eclampsia is associated with
increased levels of lipid peroxides
because cyclooxygenase activity
generates not only TAX2 but also
oxygen radicals. When oxygen
radicals interact with
polyunsaturated fatty acids they
form lipid peroxides, low dose
aspirin, by inhibiting
cyclooxygenase can reduce both TXAs
and lipid peroxides.
ADVERSE EFFECTS OF LOW DOSE ASPIRIN
Potential major clinical adverse effects are relatively rare with low dose
aspirin
MATERNAL |
FETAL |
NEONATAL |
-
Anemia
-
APH
-
PPH
-
Prolonged bleeding time
-
Prolonged gestations and
labour |
-
Congenital defects (mainly
cardiac)
-
Oligohydroamnios
-
Premature closure of ductus
arteriosus. |
-
Bleeding
disorders
-
Intraventricular hemorrhage
in preterm infants.
-
Persistent pulmonary
hypertension. |
PROSTGLANDINS IN PPH
INTRODUCTION
Active management of third stage of
labour is recommended to avoid PPH
by:
1)
Administration of a prophylactic
oxytocin during & immediately after
the delivery.
2)
Early cord cutting
3)
Delivery of the placenta by control
cord traction.
Inspite of this three measures if
PPH occurs
??
h’age is severe ?? leads to shock
??
??
Needs blood transfusion
Hypofibrinogenemia
??es morbidity + mortality & further
bleeding
??
Use of prostaglandin
??
Reduced risk for our patient to
expose to major Sx.
Why PGS : Cessation of uterine
bleeding after delivery occurs due
to vessel wall constrictions &
thrombosis.
Concentration of PGs & its
metabolite. ??es in amniotic fluid&
maternal circulation during
labour.
??
Peak level of PGF2
a in maternal circulation reached
after birth
?? &
Rapid surge with in few minutes
after placental separation.
??
Thus exogenous PGs used when
endogenous production is
insufficient to prevent hypotonia.
|
|
Carbopost – 15 methyl PG F22
??
intra muscular
Misoprostol ?? PGE1 |
PGs use |
|
|
|
??
per rectally
Orally
Sublingually
For Prevention of PPH:
In
Active Management third stage of
labour.
In high risk patients like
eclampsia, major degree placenta
previa, and severe anemia
??
125
ug of carboprost intra muscularly
ADR : diarrhoea, vomiting
Management of PPH : Initial Management
?? BGCM, fresh frozen plasma
?? Check uterine contractility
?? Recheck entity of placenta & memb.
?? Genital tract injury
If uterine atony
?? Uterine massage
?? Methergin 0.5 mg IV after 10 min
if no response then 100 unit of
syntocin +0.5 mg of methergin in
1pint NS at 90?? /min
??
if no response in 10 min
??es oxytocin 300 units + 0.5 mg of
methergin in 10 RL 90?? /min
??
No response to 10 min
Intramusculur / intra myometrial
Inj. carboprost 0.25 mg every 15-30 min.
Max : 2 mg can be given. Onset of
action with in 5 minutes.
Sulprostone 1000 ug in 10 NS 60-80??/min
?? if fail
Sulprostone 500 ug diluted in 10 ml of NS given trans-abdominally in four
uterine quadrant.
Along with pulse, BP, cardiac monitoring of patient.
PGE1 vaginal suppository
used but due to continuous bleeding
it can be washed out.
??
Continuous irrigation of uterine cavity with low concentration
of PGE2
is effective in severe PPH.
Misoprostol 800 ug/ 1000 ug per rectally.
??
Adv. over oral
Slow uptake but prolong duration of action
All this fails then Sx intervention like internal iliac artery
ligation
Internal iliac artery embolisation
Obstetric hysterectomy
Contraindication
-
Asthma |
|
|
-
Cardiac |
|
|
-
Renal |
|
diseases |
-
Hepatic |
|
|
Conclusion :
Administration of PGs is effective
in treatment of severe PPH with few
side effects.
??
It is a life saving medical therapy
for PPH.
??
Also its use avoids the need for
major surgery
??
Thus reduce morbidity & mortality
Adv. : Awareness in the staff related to labour room & maintain a readily
accessible supply of injectable PG
or its analogue in any locality
where deliveries are regularly under
taken.
USE OF PROSTAGLANDINS
IN GYNAECOLOGY
ENDOMETRIOSIS
-
Endometriosis is defined as the
presence of endometrial tissue
(glands and stroma) outside the
uterus.
-
The most frequent sites of
implantation are the pelvic viscera
and the peritoneum.
-
There are 2 groups of prostaglandins
which are most relevant to
endometriosis – good/bad.
-
Good – take part in (N) functions of
the body without contributing to the
processes which cause negative
effects of endometriosis.
-
Bad – Take part in the functions of
the body which contribute to the
signs and symptoms of endometriosis
i.e. pain, inflammation, digestive
disturbance, connective tissue
damage.
-
Women with endometriosis can alter
the balance of PG production to
reduce their symptoms by reducing
the bad PGs and aim to increase the
good PGs through their diet and with
supplements.
-
This can be done by including
vegetable, nut and seed oils in the
diet and decreasing the amount of
saturated fat, junk food and dairy
products in the diet.
-
High stress, too much sugar or
refined flours also tend to ?? the
levels of bad PGs in the body.
IMMUNOLOGIC FACTORS AND INFLAMMATION IN THE AETIOLOGY OF ENDOMETRIOSIS
-
Apoptosis is the physiologic process
of programmed cell death that
contributes to endometrial breakdown
and turnover during the late
secretory and menstrual phases of
the cycle. Ectopic endometrium is
resistant to, apoptosis which
improves the survival of endometrial
cells entering the peritoneal cavity
and also explains why ectopic
endometrium is resistant to
macrophage- mediated immune
surveillance and clearance.
-
Matrix metalloproteinases are
enzymes that degrade the
extracellular matrix and help to
mediate normal endometrial breakdown
and new estrogen stimulated growth.
Expression of matrix
metalloproteinases is increased
early in the cycle and usually
suppressed by progesterone during
the secretory phase.
-
In women with endometriosis,
secretory endometrial matrix
metalloproteinase expression is
unusually resistant to progesterone
suppression.
-
Persistent matrix metalloproteinase
expression in shed endometrial cells
can confer an invasive potential to
refluxed endometrium that
facilitates invasion of the
peritoneal surface and subsequent
cell proliferation.
-
The development and growth of
endometriosis are estrogen dependent
and there is now substantial
evidence that aromatase, the enzyme
that converts androgens to estrogen
is over expressed in women with
endometriosis.
-
Transcription factors which
stimulate the aromatase enzyme
activity (notably steroidogenic
factor-1, sf-1) are over expressed
in endometriotic tissue and those
that inhibit the enzyme are
under-expressed, resulting in
abnormal aromatase activity and
estrogen synthesis.
-
Estrogen stimulates local
cyclooxygenase type 2 (cox2)
activity that generates PGE2, a
potent stimulator of aromatase in
endometriosis- derived stromal cells
thereby creating a positive feedback
for continuous local estrogen
production
-
Endometriosis is associated with a
state of sub-clinical peritoneal
inflammation marked by ?? peritoneal
fluid volume, ?? peritoneal fluid WBC
concentration and ?? inflammatory
cytokines, growth factors and
angiogenesis promoting substances.
-
Administration of NSAIDs are used to
relieve pain Ibuprofen 800 – 1200 mg
/ day or Mefenamic acid 150-600
mg/day in quite effective.
PROSTAGLANDIN IN
MENORRHAGIA
INTRODUCTION
Cyclical bleeding at normal interval. The bleeding is either excessive in
amount or duration or both.
CAUSES
??
??es
in size of endometrial cavity &
bleeding surface.
??
??ed
vascularity of uterus
??
Endometrial hyperplasia
??
Hyper estrogenic state.
PROSTAGLANDIN IN MENORRHAGIA
??
Produce Strong uterine
contraction
??
??es
vasoconstriction ischemia of
myometrium
i.
Produce
??es pain
ii.
??es blood loos
??
??amount
of Estrogen& progesterone.
??
??ed release of prostaglandins
??ed pains, blood loss
ANTI PROSTAGLANDINS ARE USED
-
Inhibition of cyclooxygenase II
enzyme & reduce prostaglandins
-
??es pain & blood loss, ??es uterine
contraction
-
Vasodilatation & produce inhibition
of platelet aggregation ????es amount
of clots.?? es pain & blood loss.
PROSTAGLANDIN IN
DYSMENORRHOEA
Introduction
??
Definition : Painful
menstruation in sufficient magnitude
so as to incapacitate the day to day
activities.
??
Two- types
(1) Primary : Painful menstruation with out
pelvic pathology
(2) Secondary : Painful menstruation with
pelvic pathology.
Role of Prostaglandin in dysmenorrhoea
In ovulatory cycle
??
Progesterone, prostaglandins
synthesised by secretory endometrium
??
Fall in estrogen, progesterone prior
to menstruation
??
Prostaglandin release with maximum production during shedding
of endometrium
??
PG F2a ?? Strong Uterine contraction
??
Increase vaso constriction
??
Cause ischemia of myometrium
??
??
??es Pain and blood loss
??
??es sensitivity of nerve
endings to pain
CLINICAL FEATURES
- Pain
- Weakness, easy fatiguability
??
Treatment :
1) Prostaglandin synthesis
inhibitors
2) Hormonal therapy
??
Prostaglandin synthesis inhibitors :
-
Inhibit cyclo oxygenase II enzyme &
reduce prostaglandin production.
-
No binding with COX-1 enzyme.
-
Selective cyclo oxygenase II
inhibitor
-
Location GI tract mucosa, platelet,
kidney
Drugs : 1)
Rofecoxib
2) Non
steroidal anti influmatory agent
- Brufen
- Mefenamic acid
- Naproxen sodium
Dose :
T. Brufen (400 mg) 1 tds
Naproxen sodium (250 mg) 1 tds
Mefenamic acid 250 to 500 mg
bd or tds
Hormonal Therapy
Prolong suppression of estrogen&
progesterone
??
Low prostaglandin content
??
Atrophic, decidualized endometrium
PROSTAGLANDINS IN
OVARIAN CANCER
Ovulation
Arachidonic acid ?? PGs
COX-1
COX-2 Enzyme
activity mainly induced by (TNFa)
TNFa also induced proteolytic enzymes like urokinase type plasminogen
activator
Matrix metalloproteinase (2-9)
These entire factors are associated with removal, remodeling of basement
membrane of ovary.
During ovulation ?? Gonadotropins stimulate dissolution of basement memb.
mediated by COX-2
COX-2 Plays a role in ovarian surface epithelial morphological remodeling
??
May also promote & select the transformation of cells with oncogenic
mutation & neoplastic potential.
COX-1: May be reductant & compensatory for COX-2 and also contribute to
ovarian tumorigenicity.
TNFa induced COX-2 expression is lost in ovarian cancer cell.
??
Contribute to early step of ovarian epithelial neoplastic transformation.
COX-2 expression in morphologically pre-neoplastic epithelium is
stimulated by TNFa.
TNFa, urokirase plasminogen activator, MPNP-2, MMP-9 play imp. role in
ovulation & epithelial
transformation & provide, molecular
linking of ovulation & ovarian
cancer risk.
CONCLUSION :
Inflammatory activities mediated by
TNFa induced COX-2, uPA, MMP-2
??
Inducing incessant ovulation
??
Degradation & remodeling of basement membrane
Select & promotes the transformation of epithelial cells with
oncogenic potential.
Thus TNFa, COX-2, MMP-2 ?? Induces epithelial neoplastic
transformation.
Use of COX-2 inhibitors to other
chemo preventive agent
??
Can reduce risk of ovarian cancer in
high risk women.
Role of prostaglandins in ovulation & luteolysis
In addition to other steroid hormones granulosa cells also contains
specific receptor sites for
prostaglandins, clearly indicating
it’s role in normal menstrual cycle.
The LH surge appears responsible for stimulating the local synthesis of
prostaglandins concentration of PGs
increases markedly in preovulatory
follicle & is highest at ovaluation
thereby suggesting a role in
ovulatory process. Inhibition of PG
synthesis may block follicle rupture
without affecting process of
luteinization of granulosa cells &
oocyte maturation. (Luteinized
unruptured follicle)
PGI2 brings about vasodilatation ??ed vascular permeability within the wall
of preovulatory follicle.
Suggested Mechanism through which PG2 induces follicle rupture :
a)
Release of proteolytic enzymes to
digest the follicular wall.
b)
Smooth muscle fibers have been
identified in the cortical stroma &
in the the externa of ovarian
follicle. Prostaglandins may also
contract these smooth muscles
thereby aiding the extrusion of
oocyte cumulus cell mass.
This role of PGs is so well demonstrated that infertility patients should
be advised to avoid prostaglandin
synthesis inhibiting drugs.
Luteolysis :
In (N) cycle the time period from the LH midcycle to menses is
consistently close to 14 days. For
practical purposes luteal phases
lasting between 11-17 days can be
considered as normal.
The luteal phase cannot be extended indefinitely even with progressively
increasing LH exposure, indicating
that demise of corpus luteum is due
to an active luteolytic mechanism.
The decline in progesterone production occurs as estradiol again rises to
plateau at the midluteal phase
suggesting that estrogen may
initiate luteolysis. Estrogen
induced luteolysis can be blocked by
inhibiting PG synthesis. PGE2
stimulates progesterone production
whereas PGF2 inhibits progesterone
production. It appears to operate
through modulation of LH dependent
CAMP accumulation.
In proliferative phase equal amount of PGF2 & PGE2 are synthesized but in
luteal phase level of PGF2
progressively increases.
Exprimental evidence indicates that the luteolytic effect of PGF2 is
mediated by endothelin -1. PGF2
stimulates synthesis of endothelin
-1 which inhibits luteal
steroidogenesis. In addition
endothelin -1 stimulates the release
of TNF-a, a growth factor known to
induce apoptosis.
ROLE OF
PROSTAGLANDINS IN OVULATION &
LUTEOLYSIS
In addition to other steroid hormones granulosa cells also contains
specific receptor sites for
prostaglandins, clearly indicating
it’s role in normal menstrual cycle.
The LH surge appears responsible for stimulating the local synthesis of
prostaglandins. Concentration of PGs
increases markedly in preovulatory
follicle & is highest at ovulation,
thereby suggesting a role in
ovulatory process. Inhibition of PG
synthesis may block follicle rupture
without affecting process of
luteinization of granulosa cells &
oocyte maturation. (Luteinized
unruptured follicle)
PGI2 brings about vasodilatations ??ed vascular permeability within the
wall of preovulatory follicle.
Suggested Mechanism through which PGs induces follicle rupture :
c)
Release of proteolytic enzymes to
digest the follicular wall.
d)
Smooth muscle fibers have been
identified in the cortical stroma &
in the theca externa of ovarian
follicle. Prostaglandins may also
contract these smooth muscles
thereby aiding the extrusion of
oocyte cumulus cell mass.
This role of PGs is so well demonstrated that infertility patients should
be advised to avoid prostaglandin
synthesis inhibiting drugs.
Luteolysis:
In normal cycle the time period from the LH midcycle to menses is
consistently close to 14 days. For
practical purposes luteal phase
lasting between 11-17 days can be
considered as normal.
The luteal phase cannot be extended indefinitely even with progressively
increasing LH exposure, indicating
that demise of corpus luteum is due
to an active luteolytic mechanism.
The decline in progesterone production occurs as estradiol again rise to
plateau at the midluteal phase
suggesting that estrogen may
inttiate luteolysis. Estrogen
induced luteolysis can be blocked by
inhibiting PG synthesis. PGE2
stimualtes progesterone production
whereas PGF2 inhibits progesterone
production. Both appears to operate
through modulation of LH dependent
cAMP accumulation.
In proliferative phase equal amount of PGF2-a & PGE2-a are synthesized but
in luteal phase level of PGF2-a
progressively increases.
Experimental evidence indicate that the luteolytic effect of PGF2-a is
mediated by endothelin -1. PGF2-a
stimulates synthesis of endothelin
-1 which inhibits luteal
steroidogenisis. In addition
endothelin -1 stimulates the release
of TNF-a, a growth factor known to
induce apoptosis.
PGS IN BIRTH CONTROL
MEASURE
Introduction :
Prostaglandins are produced in most tissues of the body & have varying
physiological action.
On endometrium :
Prostaglandins acts in similar manner to that of hormones ?? by stimulating
target cell but they are differ from
hormones ?? as they act locally near
their site of synthesis &
metabolized very rapidly thus they
cause
??
Vasoconstriction & smooth muscles
contraction
Leads to sloughing of endometrium during menstruation
XPL7: Vaginal suppository
Contains some fatty acid which
convert into PGS
??
Produces effects on cell levels in endometrium
Herbal formulation
Comes in applicator
Used with in 72 hrs. after an
unprotected sexual exposure to
prevent pregnancy.
IUD: Causes ??es local secretion of PGs with fibrinolytic mechanism needed
for hemostasis is affected.
??
PGs causing ?? aseptic inflammatory
reactions in endometetrium
?? So
makes endometrium hostile for
implantation of blastocyst.
PGS ?? also cause asynchronous development of endometrium
??
Also cause smooth muscle contraction
& ?? uterine activity
??
So it is responsible for contraceptive effects of IUD
??
So when it inserted postcoitally with in 5 day of unprotected intercourse.
It can prevent implantation of
fertilized ovum
In abnormal uterine bleeding
?? IUD makes uterus to more sensitive to PGs.
??
So even (N) level of PG can cause a strong reaction in smooth muscle.
??
So PG suppressants will be significant in treating abnormal uterine
bleeding
Mifepristone :
Can prevent ovulation if given in proliferative phase & hinder development
of the endometrium when given so on
after ovulation.
Dose ??
10 mg up to 5 days of unprotected
inter course effectiveness 18%
High dose can be used 600 mg
effectiveness 38%
Dis adv ?? Period may be delayed up to 7
days.
PROSTAGLANDIN IN
SURGICAL PROCEDURE
Non steroidal antiflammatory agent
(Anti prostaglandin)
- Aspirin
- Carboten
- Deracoxib
M/A : Inhibition of cyclo oxygenase pathway
Inhibit
conversion of Arachidonic acid into
prostaglandin
USE : Post operative pain
relief
I)
Prostaglandins in hysteroscopic
myomectomy
M/A :
1)
After resection of protruding
portion of myoma, injection
prostaglandin (Frog)
??
Allows complete removal
2)
Uterine Neoplasm surgery
3)
Intraoperative use of prostaglandin
F2a
??
Allow one step hystero resectoscopy
of asessile submucous leiomyoma.
II)
Prostaglandin after cesarean
delivery or uterine surgery
??
Induce uterine contraction
??
Prevention of blood loss
I)
Prostaglandins in pre operative
cervical ripening
??
??es
uterine contraction
??
Promote cervical ripening
Dose :
T. Misoprost (400 microgram)
Vaginaly 3-4 hr. prior surgery
??
Allow complete evacuation
??
Less cervical dilatation
require so less chances of injury.
II)
Prostaglandin in atonic PPH
??
Intramyometrial inj.
prostaglandin given in C/o
intra-operative Atonic PPH
??
T. Misoprost per rectal can
be used in treatment of PPH.
|