SAN FRANCISCO -- Hydroxychloroquine to treat rheumatic disease seemed safe in a retrospective study of 60 pregnancies, but a separate study found that the drug does cross the placental barrier to the fetus.
The antimalarial medication is widely used to treat rheumatic disease, but controversy remains about whether to stop treatment during pregnancy. One case of fetal ototoxicity has been associated with use of the drug during pregnancy.
Because of its long half-life, discontinuing hydroxychloroquine in pregnancy will not necessarily prevent fetal exposure and may actually precipitate a flare of disease, particularly in patients with systemic lupus erythematosus, Dr. Angela Tincani said during the annual meeting of the American College of Rheumatology.
She reported on 60 pregnancies since 1995 in 55 women taking hydroxychioroquine for rheumatid disease, mainly systemic lupus (36 patients). All had been taking the drug for at least 1 year before becoming pregnant and were continued on 200 mg/day throughout gestation and after delivery Patients also took 100 mg/day of aspirin and, when needed, sometimes used other drugs such as corticosteroids, heparin, or azathioprine.
Fifty newborns (83%) were delivered at term; six (10%) were preterm deliveries. One fetus (2%) died and three (5%) were aborted. The babies weighed a mean of 3,000 g at birth; one had intrauterine growth retardation, and seven were small for gestational age. No malformations were detected. Two urinary tract infections and one streptococcal pneumonia detected at birth resolved with treatment.
Ophthalmologic exams in 16 of the infants 1 month and 12 months after birth found no abnormalities. Two babies developed retinal hemorrhages immediately after delivery-a common occurrence in premature infants-and both resolved by 1 month of age, said Dr. Tincani of the University of Milan, Italy
Nineteen infants breast-fed for 1-19 months developed normally and showed no signs of problems with vision or hearing. The investigators did not formally test hearing but will follow the cohort as they enter preschool, when hearing tests are done, she said.
Dr. Jean Charles Piette presented a separate prospective study that demonstrated for the first time that hydroxychloroquine crosses the placenta to produce nearly identical serum concentrations in the fetus and the mother.
Seven women with systemic lupus erythematosus and four women with other connective tissue diseases took 200 mg hydroxychloroquine either once a day (three patients) or b.i.d. for a daily dosage of 400 mg (eight patients) during pregnancy Tests of maternal blood and cord blood sampled at delivery showed mean blood concentrations of hydroxychloroquine at 893 ng/mL in the mother and 894 ng/mL in the fetus, he said at the meeting.
The mean gestational age at delivery was 38 weeks.
The investigators also measured hydroxychloroquine concentrations in the breast milk of two mothers who breast-fed their babies. They estimated the daily infant intake to be 0.06 mg/kg in one infant and 0.2 mg/kg in the other.
Although concentrations in breast milk were 344 ng/mL in one woman and 1,424 ng/mL in the other, the doses passed to infants through breast milk "were very very low,' said Dr. Piette of Paris. The primary investigator in the study was Dr. Nathalie Costedoat of Paris.
It would be illogical to tell mothers not to breast-feed if they had maintained hydroxychloroquine treatment throughout pregnancy Dr. Piette said.
COPYRIGHT 2002 International Medical News Group
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