Naftidrofuryl

Naftidrofuryl oxalate is a powerful vasodilator agent with an antagonist effect on 5-HT₂ receptors of the smooth muscle cells. The vasodilator effect, which occurs in both the cerebral and peripheral circulation, is probably the main action. However, the drug has also been shown to activate intracellular aerobic metabolism as demonstrated by a reduction in the level of lactic acid level and an increased level of ATP. It is claimed that this action protects cells against the metabolic effects of ischaemia. Furthermore, naftidrofuryl oxalate is a powerful spasmolytic agent.

Peak plasma levels are attained at 0.5-0.75 hours after oral dose. Some 24% of the drug (range 17-32%) is absorbed from the gastrointestinal tract. There is some pre-systemic metabolism. The plasma half life is approximately 1 hour (range 0.8-1.6 hours). The drug penetrates brain and other tissues. It is, however, 80% bound to albumin. Cumulation does not occur at a dose level of 200mg three times daily. Naftidrofuryl oxalate is excreted principally via the urine, all in the form of metabolites.

No toxic effects were seen in animal studies which provide additional information to that obtained in man. In repeated dose studies the no effect level was 25mg/kg/day or greater. There was no evidence of effects on reproduction below doses which caused maternal toxicity.