Fluphenazine Side Effects

Not all side effects for fluphenazine may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to fluphenazine: oral elixir, oral solution concentrate, oral tablets, parenteral injection

Side effects include:

Extrapyramidal reactions (e.g., pseudo-parkinsonism, dystonia, dyskinesia, akathisia, oculogyric crises, opisthotonos, hyperreflexia), drowsiness, lethargy, weight gain.

For Healthcare Professionals

Applies to fluphenazine: injectable solution, oral concentrate, oral elixir, oral tablet

Nervous system

The drowsiness associated with fluphenazine therapy may resolve after several doses.

Tardive dyskinesia involves involuntary, dyskinetic, repetitive movements and may be more common in elderly women receiving fluphenazine. Tardive dyskinesia may be irreversible and is related to both the duration of therapy and the total amount of drug consumed. Frequent discontinuation and resumption of therapy may predispose patients to the development of tardive dyskinesia.

One study has suggested that the prevalence of tardive dyskinesia in patients receiving fluphenazine for more than two years is approximately 50% and is not different form the prevalence of tardive dyskinesia in patients taking other neuroleptics. Other studies have reported a lower prevalence.

Dystonias frequently involve tongue protrusions, muscle rigidity, torticollis, and opisthotonus. Dystonias usually resolve after neuroleptic discontinuation, but may require antihistamine and antiparkinsonian therapy if symptoms are severe of if respiration is compromised. Treatment of dystonic reactions and extrapyramidal effects, in addition to general supportive measures, may include judicious use of one or more of the following: benztropine, trihexyphenidyl, biperiden or diphenhydramine.

Pseudoparkinsonism involves flat facies, pill-rolling, shuffling gait, and cogwheel rigidity. Pseudoparkinsonism symptoms may respond to judicious use of one or more of the following: benztropine, trihexyphenidyl, biperiden or diphenhydramine.

Fever, altered consciousness, autonomic dysfunction and muscle rigidity are the hallmarks of the neuroleptic malignant syndrome. The neuroleptic malignant syndrome is associated with a case fatality rate of about 20%. Immediate discontinuation of neuroleptic therapy, consideration of dantrolene (or bromocriptine) administration as well as intensive monitoring and supportive care are indicated. (Case reports have suggested an association between the neuroleptic malignant syndrome and malignant hyperpyrexia.)

Cases of suicide associated with fluphenazine induced akathisia have been reported rarely. Other authors have suggested that an association between neuroleptic use and suicide risk is uncertain.

Nervous system side effects have been common and most often included sedation and drowsiness. Tardive dyskinesia, dystonia, akathisia, pseudoparkinsonism, stuttering, increased neuromuscular excitability, tremors, seizures, and the neuroleptic malignant syndrome have also been reported.


Other side effects have included anticholinergic effects such as constipation, dry mouth, urinary retention, and blurred vision which have been reported.

Abrupt discontinuation has been reported to result in recurrence of psychosis. A case of severe debilitating rhinorrhea has also been reported following abrupt discontinuation.

Elevated body temperature and cases of prolonged fever (without the extrapyramidal symptoms associated with the neuroleptic malignant syndrome) have been reported.

A case of finger clubbing has been reported.


Hepatic side effects including transient elevations in liver function tests and cases of cholestatic jaundice have been reported.


Cardiovascular side effects including hypotension, hypertension, and arrhythmias have been reported rarely.


General side effects including weight gain and obesity have been reported frequently.


Endocrine side effects including hyperprolactinemia and galactorrhea have been reported. These effects have been reported to result in female menstrual irregularities and male sexual dysfunction in patients taking other phenothiazines. Cases of the syndrome of inappropriate secretion of antidiuretic hormone have also been reported.


Respiratory side effects have included rare cases of sudden death thought to be due to fluphenazine induced bulbar palsy, laryngeal dysfunction, and consequent aspiration have been reported.


Hematologic side effects including thrombocytopenia have been reported rarely.


Genitourinary side effects including priapism have been reported rarely. Hypersexuality, impotence, and loss of libido have also been reported.


Ocular side effects including cases of maculopathy have been associated with long-term fluphenazine therapy (and exposure to potential causes of photic damage).

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