Central Nervous System: Fluphenazine produces in general a lesser degree of central depression than the barbiturates or benzodiazepines, and tolerance to its sedative effects develops fairly quickly in most patients. It produces extrapyramidal dysfunction probably as a result of its effect on central dopaminergic transmission. Resultant disorders include acute dystonia, a parkinsonism-like syndrome, and akathisia; late effects include tardive dyskinesia and perioral tremor.
Autonomic Nervous System: It has antimuscarinic properties and may cause adverse effects such as dry mouth, constipation, difficulty with micturition, blurred vision, and mydriasis. Tachycardia, electrocardiographic changes and rarely cardiac arrhythmias may occur and hypotension is common.
Metabolism and Endocrine System: Weight change, peripheral edema, abnormal lactation, gynaecomastia, menstrual irregularities, false results on pregnancy tests, impotency in men and increased libido in women have all been known to occur in some patients on phenothiazine therapy.
Allergic Reactions: Hypersensitivity reactions include urticaria, exfoliative dermatitis, erythema multiforme and contact sensitivity.
Hematologic: Routine blood counts are advisable during therapy since blood dyscrasias including leukopenia, agranulocytosis, thrombocytopenic or nonthrombocytopenic purpura, eosinophilia and pancytopenia have been observed with phenothiazine derivatives. Furthermore, if any soreness of the mouth, gums or throat or any symptoms of upper respiratory infection occur and confirmatory leukocyte indicates cellular depression, therapy should be discontinued and other appropriate measures instituted immediately.
Hepatic: Liver damage as manifested by cholestatic jaundice may be encountered, particularly during the first months of therapy; treatment should be discontinued if this occur.
Others: Pain and irritation at the injection site have been reported.