Drug Interaction Report

GENERALLY AVOID: Coadministration with drugs that are capable of increasing the activity of delta-aminolevulinic acid synthetase (e.g., estrogens, barbiturates, steroid metabolites, rifampin) may negate the pharmacologic effect of hemin. In the treatment of porphyria, hemin is thought to limit the rate of porphyrin/heme biosynthesis by inhibiting delta-aminolevulinic acid synthetase, thus any induction of this enzyme would be expected to counteract the therapeutic effect of hemin.

MANAGEMENT: Drugs capable of increasing the activity of delta-aminolevulinic acid synthetase should be avoided during hemin therapy.

GENERALLY AVOID: Concurrent acute use of barbiturates and ethanol may result in additive CNS effects, including impaired coordination, sedation, and death. Tolerance of these agents may occur with chronic use. The mechanism is related to inhibition of microsomal enzymes acutely and induction of hepatic microsomal enzymes chronically.

MANAGEMENT: The combination of ethanol and barbiturates should be avoided.