Pregnancy and Drugs

drugsMany women ask me at the pharmacy counter if a prescription they are picking up is ok during pregnancy or if they can take something over the counter. They wonder about different foods and creams and whether vitamins are ok. There are lots of questions about this so I wanted to address it. Besides, I haven’t done any real pharmacy posts in a while so I figured why not.

Pregnancy Drug Ratings

All drugs are classified within a rating system to determine the safety profile during pregnancy. They are as follows:

A: Adequate and well-controlled human studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters)

B: Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women OR Animal studies have shown an adverse effect, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus in any trimester.

C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks

D: There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks

X: Studies in animals or humans have demonstrated fetal abnormalities and/or there is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience, and the risks involved in use of the drug in pregnant women clearly outweigh potential benefits.

A and B are the drugs that appear to have the best safety profile. Most drugs however fall into category C. A doctor may feel that the benefits of a C drug is better than any potential risk. Some of these C drugs are likely just fine to be used for a short duration, but the reality is the only thing a women should really be putting in her mouth during pregnancy is good whole food. Drugs should be avoided if possible.

OTC Drugs

Acetaminophen (Tylenol) -Class B- is generally considered safe during pregnancy and is the doctors go to for pain relief. There have been problems with acetaminophen though in the last couple of years. In a report of acetaminophen overdose from the late 90’s and early 2000-2001 the data showed that there were at least 458 deaths from overdose and 100 of those were unintentional. [1] That’s approaching 1 in 4. Just because it is sold over the counter doesn’t mean that’s it’s completely benign. Generally a total of less 3 grams/day is recommended.

Ibuprofen, Naproxen -Class C – NSAIDs are actually sometimes used during pregnancy during the first and second trimesters but no the third. There is a risk of closing the ductus arteriosus which is a blood vessel shunt between the pulmonary artery and the aorta. This shunt is necessary in utero because the lungs don’t function until the baby is born. Shutting this prematurely is bad. Babies with high levels of NSAIDs in their meconium also had increased incidence of persistent pulmonary hypertension after birth. [2] Don’t use this unless your doc says to use it.

Diphenhydramine (Benadryl) -Class B- This one can be used although it is generally avoided during the last few weeks due to a possible link with retrolental fibroplasia. It is the antihistamine of choice for acute allergic reactions during pregnancy. While generally safe during pregnancy, talk to your doc before using this.

Tums – Not rated – Caclium carbonate is safe during pregnancy at recommended doses on the bottle. This is a safe choice for reflux.

Ranitidine (Zantac) -Class B – This is the preferred antihistamine for acid during pregnancy. It’s still a good idea to talk with your doc before initiating it.

Pepto Bismol-Class C- This should be avoided. Salicylates are known to cause problems in the fetus including, jaundice, decreased birth weight and perinatal mortality. There is also the risk of fetal or maternal bleeding. [3] Just avoid the pink stuff while pregnant.

Cough Syrups -Class C- These are ok with your docs consent but be careful because many of these contain alcohol which is something you’ll want to avoid while pregnant. Also avoid any syrup that says “D” for decongestant or has pseudoephedrine or phenylephrine as a listed ingredient. This constricts blood flow. Guaifenesin and dextromethrophan are generally ok, but you should still talk with your doc. Many times drinking lots of water will help with thinning secretions and helping as an expectorant.

Antifungal Creams -Clotrimazole-Class B- This is safe even intravaginally although it is recommended that if a women have a yeast infection that she see her doc. Miconazole is similar to clotrimazole but listed as class C. There have been no deformities seen with use of either. Fluconazole, which is prescription only, should be avoided during pregnancy because it can cause skeletal abnormalities and congenital heart disease.

Simethicone-Class B- Simethicone isn’t absorbed and considered safe during pregnancy for gas and bloating. Brands include Maalox and Mylanta. Be careful though with these two brands as they contain aluminum. They are generally ok at doses on the bottle, but aluminum is not generally something that is good in the body. Using a brand like Mylanta which only contains simethicone is the better choice over Mylanta which has the aluminum in it.

Prenatal Vitamins- Not classified but safe because they are dispensed by the millions. A couple of observations here: They do have iron in them which can cause constipation. If you choose to take these, increase vegetable intake (which you should do anyway while pregnant for the vitamins) to help flow of the stool. Vegetable juicing also helps with this. A big concern is the mom not getting enough folate, especially during the first few weeks. All of these vitamins, including folate, can be readily eaten and supplementation isn’t always necessary. The only real exception here is if you have a MTHFR mutation that doesn’t allow you to produce active folate in the body, in which case you might not be able to get pregnant in the first place. Supplementing with L-methylfolate will take care of that. You can find brands with L-methylfolate but right now they will cost more

When in doubt please ask a pharmacist. If the pharmacist just thinks they know, ask them to double check. If they don’t, then fire them and get a new one. Your baby is more important than your pharmacist. Stay with a pharmacist who is willing to look it up and be sure. Remember too that good supplements are no substitute for good nutrition. Get your diet in place and then use supplements if needed.


1.Nourjah, Parivash, et al. “Estimates of acetaminophen (paracetomal)‐associated overdoses in the United States.” Pharmacoepidemiology and drug safety 15.6 (2006): 398-405.

2. Alano MA, Ngougmna E, Ostrea EM, et al. Analysis of nonsteroidal antiinflammatory drugs in meconium and its relation to persistent pulmonary hypertension of the newborn. Pediatrics 2001;107:519-23.

3.Mahadevan U, Kane S.American Gastroenterological Association Institute technical review on the use of gastrointestinal medications in pregnancy.Gastroenterology. 2006 Jul ;131(1):283-311.

Disclaimer: All info on this website is for education purposes only. Any dietary or lifestyle changes that readers want to make should be done with the guidance of a competent medical practitioner. The author assumes no responsibility nor liability  for the use or dissemination of this information. Anyone who chooses to apply this information for their own personal use does so at their own risk.


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