A Pharmacist's Guide to OTC Therapy

The Use of OTC Drugs During Pregnancy

Patient counseling is an essential aspect of pharmacy practice, and certain patient populations may require more specific attention with regard to the safety and appropriate use of medications. This is of particular importance when addressing the needs of pregnant women. Because OTC drugs are readily available and are perceived by many patients as generally safe for use in everyone, pharmacists are in a pivotal position to ascertain the appropriateness of OTC drug use during pregnancy. In general, the use of drug therapy during pregnancy should be avoided whenever possible; however, at certain times, drug therapy is warranted, and the benefits of their use may outweigh the risks.¹ Today, many OTC drug labels contain directions for pregnant women to consult a physician prior to using the product.

The OTC products most frequently used by pregnant women include analgesics,

vitamin/mineral supplements, and gastrointestinal medications (ie, antacids).¹ Results from a study involving 418 participants showed that 62.8% of the women reported that they used OTC medications and 4.1% used herbal and/or alternative remedies during their pregnancies.² Results from another study involving 578 participants revealed an estimated 92.6% reported using OTC medications, and 45.2% of the participants used herbal medications. In addition, 15% of the women took ibuprofen at some point during the pregnancy, and 5.7% used it in their third trimester.³

When evaluating the safety of a drug with regard to its effects on a fetus, 2 factors should be considered. The first factor is the stage of pregnancy.¹ For example, the first trimester poses the greatest risk for the possibility of causing major anatomic abnormalities in the fetus; however, depending upon the drug therapy, contraindications may arise if the drug therapy is continued during the other 2 trimesters as well.¹ The use of aspirin, for instance, should be avoided throughout pregnancy, especially during the last trimester, as it may increase the length of gestation and the duration of labor, as well as raise the incidence of hemorrhage in both

pregnant women and their newborns during and after delivery.¹ Aspirin also has been shown to be associated with increased incidence of still births, neonatal deaths, and low birth weight.^1,4

Studies have shown that when nonsteroidal

anti-inflammatory drugs (NSAIDs) are used near the time of conception, they may hinder a woman’s fertility by interfering with blastocyst implantation.⁴ In addition, the use of these agents has been shown to cause fetal problems in the last part of the second trimester and the third trimester, such as premature closure of the ductus arteriosus and primary pulmonary hypertension in the newborn.⁵ Although more research is needed, the current data suggest that it is important to counsel women of childbearing age and pregnant women about avoiding the use of NSAIDs from the time of possible conception through to the end of the first trimester, as well as during the last trimester, because of the proven risk of fetal toxicity.⁵ The analgesic of choice during pregnancy is acetaminophen.

The second factor to consider is the drug’s ability to pass from the mother’s circulation to the fetal circulation through the placenta.¹ The FDA classifies drugs into 5 categories of safety of use during pregnancy (Table).

Conclusion

During counseling, pharmacists can assess the appropriateness of drug use and, depending upon the ailment, make nonpharmacologic recommendations that may be beneficial to the patient. Pharmacists should stress that medications should only be used in pregnancy under the supervision of a physician, and patients should always consult with the physician or pharmacist prior to using any OTC medications, including vitamin/mineral supplements and homeopathic supplements. If drug use is deemed appropriate, patients should be advised to steer clear of combination products to avoid unnecessary drug use. Patients should always read medicine labels and adhere to dosage and administration guidelines given to them by their physicians.

References

• Isetts BJ, Brown LM. Patient Assessment and Consultation. In: Berardi RR, ed. Handbook of Nonprescription Drugs. 15th ed. Washington DC: American Pharmacists Association; 2006;30-31.
• Refuerzo JS, Blackwell SC, Sokol RJ, et al. Use of over-the-counter medications and herbal remedies in pregnancy. Am J Perinatology. 2005;22(6):321-324.
• Glover DD, Amonkar M, Rybeck BF, Tracy TS. Prescription, over-the-counter and herbal medicine use in a rural, obstetric population. Am Journal Obstet Gynecol. 2003;188(4):1039-1045.
• Gynecology and Obstetrics. In: Beers MH, Porter RS, Jones TV, Kaplan JL, Berkwits M, eds. The Merck Manual of Diagnosis and Therapy. 18th ed. 2006;2059.
• Briggs GG. Do NSAIDs Cause Birth Defects? Ob Gyn News. 2006;41(22):11. www.obgynnews.com/article/S0029-7437(06)72403-X/fulltext.
• Briggs GG, Freeman RK, Yaffe SJ. Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk. 5th ed. Baltimore, MD: Williams & Wilkins; 1998:577-578,627-628.