Can
over-the-counter pain relievers cause infertility in women?
Darrell Hulisz
Associate
Professor, Department of Family Medicine, Case Western
Reserve University; Clinical Pharmacist, University
Hospitals, Case Medical Center, Cleveland, Ohio
Nonsteroidal anti-inflammatory drugs
(NSAIDs) are among the most commonly prescribed class of
drugs worldwide and are frequently used by women of
childbearing age. The adverse gastrointestinal,
cardiovascular, and renal effects of NSAIDs are well known.
Similarly, most clinicians likely understand that using
NSAIDs in near-term pregnancy may have adverse effects,
including potential prolongation of labor, premature closure
of the fetal ductus arteriosus, and increased risk for
postpartum bleeding.[1] However, the potential for NSAIDs to
adversely affect ovulation has received much less attention,
even though this potential complication was described in the
medical literature over 2 decades
ago.[2-6]
NSAIDs are prostaglandin inhibitors
that block cyclo-oxygenase (COX)-1 and COX-2 enzyme
production. The COX enzyme system catalyzes the production
of biologically important prostaglandins. One isoenzyme,
namely COX-2, is active in the ovaries during follicular
development. Inhibition of COX-2 by NSAIDs and COX-2
inhibitors (e.g., celecoxib) is thought to potentially cause
reversible luteinized unruptured follicle syndrome (LUFS) in
a subset of patients.[1,6] This syndrome is characterized by
a failure of ovulation. While clinical signs of ovulation
(e.g., elevated body temperature and progesterone levels) do
occur, follicular rupture and ovum release are
absent.
COX-2 inhibitors may have further
adverse effects on fertility. COX-2 expression is thought to
occur not only in ovulation but also in fertilization,
implantation, and maintenance of pregnancy.[7] COX isoforms
are important in the generation of prostaglandins that are
essential for formation of proteolytic enzymes causing
rupture of the egg follicles as well as prostaglandins
crucial in angiogenesis for establishment of the
placenta.[6,7]
Sporadic case series reports of
delayed ovulation and/or LUFS in association with NSAID use
have appeared in the medical
literature.[4-6]
Prospective, randomized, controlled
trials of small sample sizes have demonstrated that NSAIDs
and COX-2 inhibitors produce a reversible delay in
follicular rupture.[8-10] The studies show a fairly
consistent pattern of apparently insignificant differences
in biological variables, such as menstrual cycle length or
overall endocrine profiles of cycles in women receiving
NSAIDs and COX-2 inhibitors vs placebo. However, unruptured
follicles were more often observed in a significantly higher
proportion of women using these agents, and this effect is
reversible upon drug discontinuation.
On the contrary, at least two small
randomized trials[11,12] and one prospective observational
cohort study[13] seem to provide reassurance that delayed
follicular rupture is unlikely to cause
infertility.
The most recent data were presented
at this year's European League Against Rheumatism (EULAR)
Annual Congress by Salman and colleagues.[14] This
prospective trial randomly assigned 39 women of childbearing
age with minor back pain to one of four groups, as
follows:
Diclofenac, 100 mg
once daily;
Naproxen, 500 mg
twice daily;
Etoricoxib (a COX-2
inhibitor not available in the United States), 90 mg once
daily; or
A control group that
received placebo.
Participants began treatment
starting on day 10 of their menstrual cycles to ensure that
a follicle developed in preparation for ovum release. Study
medications were taken for 10 consecutive days. At baseline,
progesterone levels were determined, and each woman received
an ultrasound to assess the size of the dominant follicle on
the affected ovary. After 10 days of treatment, these
assessments were repeated.
Of the women receiving NSAIDs, only
6.3% ovulated in the diclofenac group, 25% ovulated in the
naproxen group, and 27.3% ovulated in the etoricoxib group,
compared with 100% of the control group. All three treatment
groups experienced decreases in progesterone level, and
about one third of women developed functional cysts due to
unruptured follicles. Ovulation returned to normal once the
women discontinued NSAID or COX-2 inhibitor
use.
The investigators concluded that
caution is warranted due to potential adverse effects of
these drugs on female fertility, and avoidance of NSAIDs and
COX-2 inhibitors should be considered in women planning to
conceive. It is important to note that these study results
have only been published as a poster presentation in a
journal supplement as part of the EULAR meeting
proceedings.[14]
In conclusion, no large-scale,
prospective controlled trials have proven a causal link
between NSAID or COX-2 inhibitor use and female infertility;
however, small controlled studies and case reports have
demonstrated an association between the use of these drugs
and LUFS, delayed ovulation, or ovulation failure. In the
future, more robust studies are warranted to determine the
clinical significance of these findings and to delineate
differences, if any, between NSAIDs and COX-2 inhibitors.
Given that NSAIDs and COX-2 inhibitors are commonly
prescribed and used over-the-counter by women of
childbearing age, clinicians should be aware of these
potential adverse effects, particularly in women
experiencing infertility.
For now it seems prudent to advise
temporary withdrawal of these drugs and substitution with
acetaminophen when clinically appropriate in women with
fertility concerns.
References
1. Stone S,
Khamashta MA, Nelson-Piercy C. Nonsteroidal
anti-inflammatory drugs and reversible female infertility:
is there a link? Drug Saf. 2002;25:545-551.
2. Priddy AR,
Killick SR, Elstein M, et al. The effect of prostaglandin
synthetase inhibitors on human preovulatory follicular fluid
prostaglandin, thromboxane, and leukotriene concentrations.
J Clin Endocrinol Metab. 1990;71:235-242. Abstract
3. Athanasiou
S, Bourne TH, Khalid A, et al. Effects of indomethacin on
follicular structure, vascularity, and function over the
periovulatory period in women. Fertil Steril.
1996;65:556-560. Abstract
4. Akil M, Amos
RS, Stewart P. Infertility may sometimes be associated with
NSAID consumption. Br J Rheumatol. 1996;35:76-78. Abstract
5. Smith G,
Roberts R, Hall C, Nuki G. Reversible ovulatory failure
associated with the development of luteinized unruptured
follicles in women with inflammatory arthritis taking
nonsteroidal anti-inflammatory drugs. Br J Rheumatol.
1996;35:458-462. Abstract
6. Mendon??a LL,
Khamashta MA, Nelson-Piercy C, Hunt BJ, Hughes GR.
Non-steroidal anti-inflammatory drugs as a possible cause
for reversible infertility. Rheumatology (Oxford).
2000;39:880-882. Abstract
7. Matsumoto H,
Ma W, Smalley W, Trzaskos J, Breyer RM, Dey SK.
Diversification of cyclooxygenase-2-derived prostaglandins
in ovulation and implantation. Biol Reprod.
2001;64:1557-1565. Abstract
8. Pall M,
Frid??n BE, Br??nnstr??m M. Induction of delayed follicular
rupture in the human by the selective COX-2 inhibitor
rofecoxib: a randomized double-blind study. Hum Reprod.
2001;16:1323-1328. Abstract
9. Bata MS, Al-Ramahi
M, Salhab AS, Gharaibeh MN, Schwartz J. Delay of ovulation
by meloxicam in healthy cycling volunteers: a
placebo-controlled, double-blind, crossover study. J Clin
Pharmacol. 2006;46:925-932. Abstract
10. Jesam C,
Salvatierra AM, Schwartz JL, Croxatto HB. Suppression of
follicular rupture with meloxicam, a cyclooxygenase-2
inhibitor: potential for emergency contraception. Hum Reprod.
2010;25:368-373. Abstract
11. Edelman AB,
Jensen JT, Doom C, Hennebold JD. Impact of the prostaglandin
synthase-2 inhibitor celecoxib on ovulation and luteal
events in women. Contraception. 2013;87:352-357. Abstract
12. Uhler ML, Hsu
JW, Fisher SG, Zinaman MJ. The effect of nonsteroidal
anti-inflammatory drugs on ovulation: a prospective,
randomized clinical trial. Fertil Steril. 2001;76:957-961. Abstract
13. Matyas RA,
Mumford SL, Schliep KC, et al. Effects of over-the-counter
analgesic use on reproductive hormones and ovulation in
healthy, premenopausal women. Hum Reprod.
2015;30:1714-1723. Abstract
14. Salman S, Sherif
B, Al-Zohyri A. Effects of some non-steroidal
anti-inflammatory drugs on ovulation in women with mild
musculoskeletal pain. Ann Rheum Dis. 2015;74(Suppl
2):117-118. |