Pipotiazine (Piportil), also known as Pipothiazine, is a typical antipsychotic of the phenothiazine class used in the United Kingdom and other countries for the treatment of schizophrenia. Its properties are similar to those of chlorpromazine. Piportil® L4 (pipotiazine palmitate) is the palmitic ester of pipotiazine, a piperidine phenothiazine with antipsychotic properties and weak sedative activity. The esterification of pipotiazine is responsible for its prolonged duration of action. The onset of action appears usually within the first 2 to 3 days after injection and the effects of the drug on psychotic symptoms are significant within one week. Improvement in symptomatology lasts from 3 to 6 weeks, but adequate control may frequently be maintained with one injection every 4 weeks. However, in view of the variations in individual response, careful supervision is required throughout treatment. Piportil L4 has actions similar to those of other phenothiazines. Among the different phenothiazine derivatives, Piportil L4 appears to be less sedating and to have a weak propensity for causing hypotension or potentiating the effects of CNS depressants and anesthetics. However, it produces a high incidence of extrapyramidal reactions.