Penfluridol (Semap, Micefal, Longoperidol) is a highly potent, first generation diphenylbutylpiperidine antipsychotic.

[3] Related to other diphenylbutylpiperidine antipsychotics, pimozide and fluspirilene, penfluridol has an extremely long elimination half-life and its effects last for many days after single oral dose.

Its antipsychotic potency, in terms of dose needed to produce comparable effects, is similar to both haloperidol and pimozide.

Due to its extremely long-lasting effects, it is often prescribed to be taken orally as tablets only once a week (q 7 days).

The once-weekly dose is usually 10–60 mg. A 2006 systematic review examined the use of penfluridol for people with schizophrenia: