During long-term therapy, periodic liver function tests should be performed. In addition, blood counts should be conducted regularly, particularly during the first 2 or 3 months of treatment, and physicians should watch for any signs of blood dyscrasia. Methotrimeprazine does not alter EEG activity. Nevertheless, since phenothiazines can lower the threshold of cortical excitation, it is advisable to administer an appropriate anticonvulsant medication to epileptic patients receiving Nozinan therapy. Drowsiness may appear early in treatment but will gradually disappear during the first weeks or with an adjustment in the dosage.
Extrapyramidal effects are rare and usually appear only after prolonged therapy at high doses.
These reactions may be corrected either by reducing the dose of Nozinan or by administering an antiparkinsonian agent. Orthostatic hypotension may be encountered at the start of treatment by the parenteral route or with high oral doses. Rare instances of agranulocytosis have been reported. Weight gain has been occasionally reported in patients during prolonged treatment with high doses. Skin reactions due to photosensitivity or allergies are extremely rare.