|
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:
- 3870 infants with cardiovascular defects
- 1962 infants with oral clefts
- 1100 infants with urinary tract defects
- 8387 control infants with malformations the risk
of which is not reduced after vitamin supplementation.
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
- Oral clefts
- 160% increase
It was determined that the use of antiepileptic
drugs at any time during pregnancy caused the following increased risks:
- Cardiovascular
defects - 120% increase
- Oral clefts
- 150% increase
- Urinary tract
defects - 150% 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.
|