Warfarin teratogenicity

Teratogenic effects have been observed in humans after maternal warfarin exposure. The effects are primarily seen in the nasal region of the fetus and include nasal hypoplasia, bone stippling, and mental retardation. Central nervous system abnormalities due to localized hemorrhaging and scarring have occurred after second- or third-trimester exposures, whereas exposure during early pregnancy may result in dysmorphism. ... 

As noted above, OC failure may lead to accidental pregnancy and exposure of the developing fetus to potentially teratogenic properties of CBZ ( 383). Therefore, OC levels should be closely monitored and patients should notify their physician of spotting, an indicator of OC failure. Prothrombin time and the International Normalized Ratio (INR) should be monitored when patients are on warfarin and CBZ concomitantly. Patients stabilized on an antipsychotic may decompensate when CBZ is added. This may necessitate an increase in the antipsychotic dose and is one indication for TDM of antipsychotic drug levels ( 384). Conversely, when CBZ is discontinued, the dose of these other agents may need to be lowered to avoid toxicity. In summary ... 

SAFETY PROFILE Poison by intraperitoneal route. Moderately toxic by ingestion and subcutaneous routes. An experimental teratogen. Human reproducdve effects by ingestion developmental abnormalities of the cardiovascular system, stillbirth, and unspecified neonatal effects. An andcoagulant. See also WARFARIN and ESTERS. When heated to decomposidon it emits acrid and irritadng fumes. 

Drugs known to be teratogenic include cytotoxics, warfarin, alcohol, lithium, methotrexate, phenytoin, valproate, ACE inhibitors and isotretinoin. Selective interference can produce characteristic anatomical abnormalities, and the phocomelia (flipper-Uke) limb defect was one factor that caused thalidomide to be so readily recognised. (For an account of thalidomide see p. 81.)... 

C. Delavirdine Drug interactions are a major problem with delavirdine, which is metabolized by both CYP3A4 and CYP2D6. Its blood levels are decreased by antacids, ddl. phenytoin. rifampin, and nelfinavir. Conversely, the blood levels of delavirdine are increased by azole anti-fiingals and macrolide antibiotics. Delavirdine increases plasma levels of several benzodiazepines, nifedipine, protea.se inhibitors, quinidine, and warfarin. Delavirdine causes skin rash in up to 20% of patients, and the drug should be avoided in pregnancy since it is teratogenic in animals. 

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