Pharmacokinetics and safety of tazarotene.

The pharmacokinetic profile of tazarotene helps to ensure that systemic exposure to the drug and its metabolites is minimal. First, percutaneous penetration is limited, with less than 6% of the applied drug being absorbed into the bloodstream. Second, tazarotene is rapidly metabolized into tazarotenic acid and other metabolites that are not lipophilic. Third, tazarotene and its metabolites are rapidly eliminated from the blood in the urine and feces. These three pharmacokinetic features help to ensure that post-treatment plasma levels of tazarotene and its metabolites are comparable to those of endogenous retinoids, which suggests that the risk of teratogenic effects is minimal. Limited systemic exposure to the drug also ensures that any adverse effects are local effects rather than systemic effects. Overall, tazarotene has a good safety profile and is not associated with contact sensitization, phototoxicity, photoallergic reactions, mutagenicity, or carcinogenicity.