Most women welcome the growing belly and telltale glow that come with pregnancy, but pregnancy can also bring on some unpleasant symptoms. One common problem is heartburn.

Heartburn often starts late in your first trimester and may get worse throughout your pregnancy. It should go away after you have your baby, but in the meantime, you may wonder what you can do to ease the burn. You may be tempted to turn to an over-the-counter (OTC) medication, such as Zantac, to reduce acid. But before you do, here’s what you need to know about its safety during pregnancy.

During pregnancy, your body makes more of the hormone progesterone. This hormone may relax the valve between your stomach and esophagus. Most of the time, the valve stays closed to keep acid in your stomach. But when it’s relaxed, such as in pregnancy, the valve may open and allow stomach acid to go into your esophagus. This leads to irritations and symptoms of heartburn.

What’s more, as your uterus expands, it puts pressure on your digestive tract. This may also send stomach acid into your esophagus.

Read more: Preventing acid reflux and heartburn »

Zantac is considered safe to take at any time during pregnancy. OTC drugs do not have pregnancy categories, but prescription Zantac is considered a pregnancy category B drug by the U.S. Food and Drug Administration (FDA). Category B means that studies have shown Zantac is not harmful to a developing fetus.

Still, doctors normally do not recommend Zantac for pregnant women as the first treatment for mild heartburn that occurs infrequently, or less than three times per week. They often first suggest changing your diet or other habits. If that doesn’t work, they may suggest medication.

The first-line drug treatment for heartburn in pregnancy is an OTC antacid or prescription sucralfate. Antacids only contain calcium, which is considered safe throughout pregnancy. Sucralfate acts locally in your stomach and only a small amount absorbs into your blood stream. That means there’s a very low risk of exposure for your developing baby.

If those drugs don’t work, then your doctor may suggest a histamine blocker such as Zantac.

Zantac takes a while to work, so you take it in advance to prevent heartburn. You can take Zantac 30 minutes to one hour before you eat. For mild heartburn that doesn’t occur very often, you can take 75 mg of the drug once or twice per day. If you have moderate heartburn, you can take 150 mg of Zantac once or twice per day. Talk to your doctor or pharmacist to decide which dosage is right for you.

Do not take Zantac more than twice per day. The maximum dosage is 300 mg per day. If your heartburn lasts after two weeks of treatment with Zantac, tell your doctor. Another condition may be causing your symptoms.

Learn more: 10 tips for soothing heartburn in pregnancy »

Most people tolerate Zantac well. But the medication can cause some unwanted side effects. Some of the common side effects from Zantac can also be caused by pregnancy. These include:

  • headache
  • drowsiness
  • diarrhea
  • constipation

Zantac may also cause dizziness. This side effect is dangerous because it may cause you to fall, which can be especially worrisome during pregnancy. Tell your doctor if you have any dizziness.

Rarely, Zantac may cause serious side effects. This includes low platelet levels. Platelets are needed for your blood to clot. Your platelet levels will return to normal, though, once you stop taking the medication.

To be absorbed by your body, some drugs need stomach acid. Zantac reduces the acid level in your stomach, so it can interact with medications that require stomach acid. The interaction means they won’t work as well to treat your condition. These drugs include:

  • ketoconazole
  • itraconazole
  • indinavir
  • atazanavir
  • iron salts

Zantac is an acid reducer. It’s used to relieve heartburn from indigestion and sour stomach, which may be due to eating or drinking certain foods and beverages. Zantac comes in certain strengths that are available as OTC drugs without a prescription from your doctor.

SymptomActive ingredientHow it worksSafe to take if pregnant?
HeartburnRanitidineReduces the amount of acid that your stomach makesYes

OTC Zantac only comes as a tablet you take by mouth. The main active ingredient in Zantac is ranitidine. It comes in strengths of 75 mg and 150 mg. It’s also available in different strengths and forms as a prescription drug.

Zantac belongs to a class of medications called histamine (H2) blockers. By blocking histamine, this drug reduces the amount of acid produced in your stomach. This effect prevents heartburn symptoms.

OTC Zantac is used to prevent and treat heartburn symptoms from acid indigestion and a sour stomach. Prescription-strength Zantac is used to treat more serious gastrointestinal diseases. These include ulcers and gastroesophageal reflux disease (GERD).

This drug won’t help with nausea, unless the nausea is directly related to the heartburn. If you suffer from morning sickness or nausea during pregnancy, like many other women, ask your doctor how to treat it.

If you’re dealing with heartburn during pregnancy, ask your doctor these questions:

  • What’s the safest way to relieve my heartburn?
  • Can I take OTC Zantac at any time during my pregnancy?
  • What dosage of Zantac should I take?
  • If Zantac is bringing me relief, for how long is it safe to take?

Remember, if you’re still suffering from heartburn after using Zantac for two weeks, tell your doctor. Another health issue could be to blame. Tell your doctor right away if you also have:

  • trouble or pain while swallowing food
  • vomiting with blood
  • bloody or black stools
  • heartburn symptoms for longer than three months

These may be signs of a serious condition, such as an ulcer or serious stomach problems.