Originally published in The Ottawa Citizen August 19, 2003
Original Title: Medication safety during pregnancy

Moms-to-be should speak to their pharmacist and doctor about prescription medications and any other drugs they might be taking’ What medications are safe to use during pregnancy? Should I stop my prescription medications? How can I treat my heartburn? Can I drink coffee?”

Health care providers need accurate information to answer these questions. Some women have medical conditions that require ongoing treatment. If they stop, they could increase the potential risk to their baby and themselves.

Minor health problems might require medical therapy, and pregnant women may use over-the-counter medications (OTCs) to treat them.

There is understandable angst and concern about medication use during pregnancy. One or two per cent of birth defects are due to drug exposure during that time. Ninety five per cent of defects are due to random chance or genetics.

It is unethical to subject pregnant women to clinical trials to establish the safety of a particular medication. The risk to the fetus and mother outweigh any potential benefit of the research — a lesson learned from the use of thalidomide.

In 1975, the U.S. Food and Drug Administration defined pregnancy risk factors for all drugs, and Motherisk (www.motherisk.org) provides a similar service to the public and health care providers.

In June, the Centre for Addiction and Mental Health (CAMH) released a booklet called Is it Safe for My Baby? It offers assessment of risk and recommendations for the use of medication, alcohol, tobacco and other drugs during pregnancy and breastfeeding.

This excellent guide reviews the safety of more than 200 substances when pregnant or breastfeeding. It includes a host of information covering over-the-counter and prescription medications, illegal drugs, herbal preparations, cosmetics, household chemicals, solvents, paints and cleaners.

The booklet’s release comes at a time when some prescription-only medications are now reclassified as OTC medications.

Pregnancy is not a static situation. Certain medications might be safe in the last trimester but not in the first. The reverse is also true. Let us look at some common concerns during pregnancy: pain, heartburn, nausea, constipation, caffeine, tobacco, marijuana and herbal remedies.

Tylenol (acetaminophen) is present in many OTC cold and flu medications. There is no known link between it and birth defects. ASA-containing products such as Aspirin and non-steroidal anti-inflammatory (NSAID) medications seem to be safe in the first two trimesters of pregnancy but only in low doses. However, greater doses might cause bleeding in the newborn, decreased birth weight and prolonged pregnancy.

Therefore, ASA and NSAIDs should not be used in the last trimester (28 to 40 weeks).

Infrequent use of Tylenol with codeine or other prescription narcotics is safe, but daily use can increase the risk of miscarriage, premature delivery and complications during delivery. If possible, stick with acetaminophen alone to treat pain.

Heartburn can worsen as the size of the uterus increases. Increasing pressure within the abdominal cavity can cause stomach acid to splash up into the esophagus. Antacids such as Tums, Maalox, Rolaids and Gaviscon are generally safe to use throughout pregnancy. If these options fail, the use of Zantac or Pepcid would be the next safe step.

For nausea, Diclectin (pyridoxine/doxylamine) is the only medication approved by the Society of Obstetricians and Gynecologists of Canada for use during pregnancy. The society does not recommend Gravol (dimenhydrinate) for routine use, but it is used in its intravenous form for severe vomiting and dehydration (hyperemesis gravidarum).

Fibre laxatives such as Metamucil or Prodiem and stool softeners Soflax and Colace are safe to use. The stimulant laxatives such as Ex-Lax, cascara and castor oil might cause uterine contractions and should be a last resort.

Caffeine in excess of 300 milligrams per day (three regular cups of coffee) can increase the risk of miscarriage and low birth weight babies. Caffeine consumption in a combination of other products such as 500 millilitre energy drinks (50 to 125 milligrams), a 45-gram chocolate bar (50 milligrams), 355-millilitre colas (30 to 90 milligrams) and a cup of tea (20 to 90 milligrams) can easily exceed the maximum allowable daily limit.

The harm from tobacco is dose-dependent. The more you smoke, the greater the miscarriage risk, premature delivery and low birth weight babies. It is the carcinogenic compounds and other chemicals rather than the nicotine that increase the health risk to the fetus.

Cannabis (marijuana) poses the same risk to the fetus as tobacco with an extra caveat: Newborns might have more sleep disturbances and other cognitive difficulties.

While some clinical data exists for some herbal remedies, the effect of others remains unknown. Ginkgo biloba can cause bleeding, dong quai (ephedra) and feverfew can induce premature labour.

Discuss your concerns with your doctor or pharmacist before taking medication and review all your prescription medications during your pregnancy.

The information booklet is available from CAMH for $2.50 (1-800-661-1111 or by contacting marketing@camh.net).

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© Dr. Barry Dworkin 2003