Certain drugs, such as those known to be folic acid antagonists, can lower a woman's folic acid levels and increase the risks of birth defects, should she become pregnant, a new study shows.

Researchers assessed exposure to folic acid antagonist drugs and to certain antiepileptic drugs in infants born with the following infants:

Mothers were interviewed within six months after delivery about their medication use during pregnancy.

The following medication are considered folic acid antagonists:

• trimethoprim
  
• triamterene
  
• carbamazepine
  
• phenytoin
  
• phenobarbital
  
• primidone
  

It was determined that the use of folic acid antagonist drugs during the second or third month after the last menstrual period caused the following increased risks:

• Cardiovascular defects - 240% increase

It was determined that the use of antiepileptic drugs at any time during pregnancy caused the following increased risks:

• Cardiovascular defects - 120% increase

Maternal use of multivitamin supplements containing folic acid reduced the adverse effects of folic acid antagonist drugs, but not the effects of the antiepileptic drugs.

The New England Journal of Medicine, November 30, 2000; 343: 1608-14.

Dr. Mercola's Comments:

In addition to the drugs mentioned in the study, there are many other drugs that are known to deplete folic acid levels: Aspirin Cimetidine Methotrexate Ranitidine Bismuth Citrate Barbiturates Colestipol Methsuximide Ranitidine Hydrochloride Carbamazepine Corticosteroids Nizatidine Salsalate Celecoxib (Celebrex) Ethosuximide NSAIDs Sulfasalazine Cholestyramine Resin (Questran) Famotidine Oral Contraceptives Triamterene Choline Magnesium Trisalicylate Hydrochlorothiazide and Triamterene Phenytoin Trimethoprim Choline Salicylate Indomethacin Primidone Valproic Acid The best food sources of folic acid are leafy dark green vegetables and eggs. Other foods high in folic acid are: beets, broccoli, Brussel sprouts, orange juice, cabbage, cauliflower, cantaloupe, and kidney and lima beans. In addition, folic acid is also synthesized by the "friendly" intestinal bacteria, so maintaining a healthy gut is also important. This is best achieved by following the diet and avoiding antibiotics as such as possible. Related Articles: Severe Stress During Pregnancy May Cause Birth Defects Vegetarian diet in pregnancy linked to birth defects COUGH SUPPRESSANT LINKED TO BIRTH DEFECTS MOTHER'S WORK TIED TO BIRTH DEFECTS