Nitrofurantoin in Pregnancy

Mainly sold under the trade name Macrobid, nitrofurantoin is an antibiotic used to clear bladder infections. It works well but is not that effective for kidney infections. When taken orally, it slows down the multiplication of bacteria. It first came into the market in 1953 and is now among the most essential medications required in a basic health system. Many experts believe you should have nitrofurantoin in pregnancy. But under what circumstances can you take this antibiotic in pregnancy? Find out now.

Nitrofurantoin During Pregnancy

While nitrofurantoin is commonly used in the treatment of urinary tract infections, it may also help clear other types of bacterial infections. However, it is a pregnancy category B drug, meaning that animal reproduction studies have failed to show any risks to fetus and there is no enough and well-controlled studies on pregnant women, which means you should take it only when it is clearly needed. There are also certain times when the use of this drug is contraindicated – this is usually during delivery and labor, as well as during 38 to 42 weeks of pregnancy. You should never take it if you are in the last 2-4 weeks of pregnancy.

When given late in pregnancy, it increases the risk of hemolytic anemia in the newborn because the newborn has underdeveloped enzymatic pathways required for glutathione metabolism. Nitrofurantoin in pregnancy may also cause oxidative damage to the red blood cell. Moreover, it increases the chances of developing neonatal jaundice in newborns.

Related Studies

Animal studies have not found any evidence of teratogenicity or fetotoxicity except when given in very high doses. Unfortunately, no controlled data in human pregnancy is yet available. No case related to congenital anomalies caused by nitrofurantoin use has ever been reported. According to a retrospective review involving 91 pregnancies, there was no evidence to link nitrofurantoin use to birth defects. In another study, nitrofurantoin was administered to 1292 pregnant women during their first trimester. It was also given to 9998 women at no specific time during pregnancy. Women taking it during their first trimester gave birth to babies with about 52 birth defects (55 expected), with 15/12 cardiovascular defects, 3/2 limb reductions, 1/0 oral clefts, and 5/3 hypospadias.

Nitrofurantoin and Breastfeeding

Nitrofurantoin in pregnancy should only be taken when clearly needed, and the American Academy of Pediatrics has tagged it as compatible with breastfeeding. However it is worth pointing out that it can be excreted into human milk; theoretically there is still a risk of hemolytic anemia and G-6-PD-deficient infants. It is, therefore, a good idea to avoid it if the breastfeeding infant is less than one month old. You have to decide whether to discontinue nursing or stop taking the drug depending on the importance of the drug for the mother' current situation.

What Other Side Effects Will Nitrofurantoin Bring About?

You should seek immediate medical attention if you develop signs of an allergic reaction, such as difficult breathing, hives, and swelling of tongue, lips, face or throat. You should discontinue its use if you have serious side effects, such as:

  • Bloody or watery diarrhea
  • Shortness of breath
  • Wheezing with sudden chest pain and dry cough
  • Chills, fever, unexplained weight loss, and body aches
  • Numbness, pain, or tingling in the feet and hands
  • Upper stomach pain, nausea, dark urine, itching, jaundice or clay-colored stools
  • Easy bruising, pale skin and weakness
  • Severe headache, dizziness, pain behind the eyes and ringing in the ears

You may also experience some less severe side effects when taking nitrofurantoin.  The list includes mild diarrhea, upset stomach, brownish urine, vomiting and vaginal discharge or itching.

How to Take Nitrofurantoin

Be sure to drink a full glass of water with each dose and take it with food. If you are using it in liquid form, you should shake it well before use. Use a special dose-measuring spoon to take the right dose. You can mix your liquid dose with milk, water or fruit juice, but drink the mixture completely.

You should always take it as prescribed by your doctor. Never change its dose without asking your doctor. Do not use nitrofurantoin over an extended period or it may affect liver, kidney and lung function.

Who Should Avoid Nitrofurantoin

You already know that nitrofurantoin in pregnancy is not always recommended, but there are other situations when you should avoid taking it. Do not take it if you are allergic to it or you have a history of jaundice. You should avoid it when you are urinating less than usual or you have a severe kidney disease. Always inform your doctor if you have anemia, kidney disease, diabetes, G6PD deficiency, vitamin B deficiency, or other serious diseases. The FDA has listed it as pregnancy category B medicine, so you should always inform your doctor about your pregnancy before you start using nitrofurantoin.