Skip to main content

Promazine Side Effects

Medically reviewed by Last updated on Sep 2, 2022.

Applies to promazine: injectable solution, oral tablet

Nervous system

Nervous system side effects are common and include drowsiness, dystonia, akathisia, athetoid movements and other extrapyramidal effects. Mutism has also been reported.[Ref]


Involuntary rhythmical movements of the tongue, face and mouth characterize tardive dyskinesia. Early recognition of premonitory symptoms of tardive dyskinesia (like hyperkinetic dysarthria and fine vermiform movements of the tongue) may allow discontinuation of promazine before irreversible dyskinesia ensues.

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 and intensive monitoring and supportive care are indicated.

Withdrawal symptoms have included sweating, hypotension, insomnia, nausea, vomiting, constipation and diarrhea.[Ref]

Other side effects including tardive dyskinesia have been reported after administration of other phenothiazines and may be irreversible.

The neuroleptic malignant syndrome has been reported to occur in as many as 0.5 to 1% of patients taking other neuroleptic agents.

Withdrawal symptoms after abrupt discontinuation of promazine and other neuroleptics have been reported.

Sudden death after parenteral administration of other neuroleptics has been rarely reported in patients without underlying medical illness.[Ref]


Local side effects including intravenous and inadvertent intra-arterial injection of promazine have been associated with distal necrosis requiring amputation of the affected limb.[Ref]


Gastrointestinal side effects including nausea, vomiting, constipation, excessive salivation, and dry mouth have been reported.[Ref]


Endocrine side effects including hyperprolactinemia, galactorrhea, amenorrhea, gynecomastia, and (less frequently) hyponatremia have been reported with other neuroleptics.[Ref]


Hematologic side effects including agranulocytosis have been reported rarely.[Ref]


Genitourinary side effects including priapism, urinary incontinence, nocturnal enuresis, and spontaneous ejaculation have been reported with other neuroleptics.[Ref]


Immunologic side effects including Raynaud's phenomenon and a lupus-like syndrome have been reported with other neuroleptics.[Ref]


Cardiovascular side effects including nonspecific EKG changes of uncertain clinical significance, orthostatic hypotension, tachycardia, and syncope have been reported with other neuroleptics.[Ref]


Oncologic side effects including endometrial adenocarcinoma has been reported in association with neuroleptic induced hyperprolactinemia.[Ref]

Some investigators have suggested that endometrial sampling be performed in women taking neuroleptics if warranted by clinical suspicion.[Ref]


1. Hu OY, Tang H-S, Sheeng T-Y, et al. "Pharmacokinetics of promazine I: disposition in patients with acute viral hepatitis B." Biopharm Drug Dispos 11 (1990): 557-68

2. Marcotte DB "Neuroleptics and neurologic reactions." South Med J 66 (1973): 321-4

3. Behrman S "Mutism induced by phenothiazines." Br J Psychiatry 121 (1972): 599-604

4. Yesavage JA, Tanke ED, Sheikh JI "Tardive dyskinesia and steady-state serum levels of thiothixene." Arch Gen Psychiatry 44 (1987): 913-5

5. "Product Information. Sparine (promazine)." Wyeth-Ayerst Laboratories (2001):

6. Fisher TL "Intravenous promazine: a cautionary note." Can Med Assoc J 95 (1966): 367

7. Ash PR, Bouma D "Exaggerated hyperprolactinemia in response to thiothixene ." Arch Neurol 38 (1981): 534-5

8. Akintonwa DA "A new concept in the relationship between biochemical reaction mechanisms and molecular basis of agranulocytosis." Biochem Med 32 (1984): 151-60

9. Balon R, Berchou R, Han H "Priapism associated with thiothixene, chlorpromazine, and thioridazine." J Clin Psychiatry 48 (1987): 216

10. Shenoy RS "Nocturnal enuresis caused by psychotropic drugs." Am J Psychiatry 137 (1980): 739-40

11. Keitner GI, Selub S "Spontaneous ejaculations and neuroleptics." J Clin Psychopharmacol 3 (1983): 34-6

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.