Pregnancy: What's Safe? What's Not?

About 90 percent of the questions patients ask me involve whether something will hurt their babies. Unfortunately, there are only two sources of information regarding harmful substances that are either ingested, worn, or contacted. One is the FDA, which is in charge of approving medicines (and I suppose, food, although I haven't seen any FDA-approved Twinkies yet). Luckily, their stamp is all over prescription drugs and there is an FDA classification of which drugs are harmful or potentially harmful to a developing baby (see below).

The other source of information is the marketplace, where harmful products are removed due to side effects, proven and unproven, and the unbearable costs in defending them in courts. Bendectin is one such drug, a combination of an antihistamine and vitamin B6. Bendectin was exonerated in studies, but the legal challenges became too expensive. Business is business, and Bendectin was voluntarily withdrawn.

If a company even smells trouble, it often will withdraw a product before the lawsuits pile up, because the legal impact on profits will have to be figured into any corporate balance sheet. If Oprah says she is allergic to a certain medicine, the same reaction or side effect will crop up at law offices all over the country.

So while the FDA checks these things out on the front end, it's the marketplace, with its unofficial studies involving millions (that's you, the consumer) that gives a product the final clearance. Consider the FDA-approved, weight-loss drug Redux. Heart valve damage began cropping up after its general release, and Redux is now history.

So is it safe to take new drugs that are FDA approved?

New Prescription Drugs

Although no one can say whether the large studies accepted by the FDA will be corrected by the even larger studies of the population at large, a patient has to rely on some things in this life to get along. It's not much of a problem if you have a cold, but if you have epilepsy and a new drug eliminates an undesirable effect, you will try it. Even though there are episodes that surprised everyone, the FDA is very thorough. (Aspirin would probably have a tough time if judged by the current standards.) Everything boils down to risk vs. benefit.

BOTTOM LINE: If the benefit of a new drug outweighs the risk or, more correctly, the theoretical risk, then it's probably a safe bet. Your doctor makes that call.

Antibiotics

Most of the antibiotics are safe, but there are important exceptions. Tetracycline—a popular prescription for acne—or any version of it can deform a developing baby's teeth and possibly bones. Sulfur drugs taken close to term can affect how bilirubin is handled in your baby, leading to brain damage. Cloramphenicol, leading to the fatal grey baby syndrome, has only been reported when given to a newborn, although that's good enough for a prospective mother not to take it. Quinolones, like Floxin (popularized with Anthrax terrorism) has some disappointing animal studies that earn a warning, although it's been used safely in humans in limited observations. (The data are small in these cases, because it's hard to get pregnant patients to line up for a study to see if a certain drug will hurt their babies.) All of the penicillins seem safe and have a lengthy track record, having been the very first modern antibiotic discovered. Likewise, cephalosporins, like Keflex, are safe. So are erythromycins. My favorite drug for bladder infections, nitrofurantoin (Macrodantin), is not only safe in most cases but also has a low failure rate.

With all of these drugs, if applied to hundreds of millions of persons, one can find truly terrifying side effects here and there. I would say, though, that there's more of a chance of you dying from a sinus infection (which goes on to become pneumonia, sepsis, and death) than having a side effect from an antibiotic that was reported in one out of 500,000 cases.

BOTTOM LINE: There is a large assortment of time-honored safe antibiotics to take for almost any type of infection, and your doctor will know the ones to avoid.