Fluphenazine Decanoate is indicated in the long-term management of psychotic disorders including:

• Schizophrenia
• Mania and
• Organic brain syndrome

Fluphenazine blocks postsynaptic dopamine D1 and D2 receptors in the mesolimbic system and decreases the release of hypothalamic and hypophyseal hormones. It produces calmness and reduces aggressiveness with disappearance of hallucinations and delusions. Fluphenazine Decanoate is a phenothiazine derivative. It is a highly potent antipsychotic agent with a markedly extended duration of action, available for intramuscular administration. The esterification of Fluphenazine with decanoic acid markedly prolongs the drug's duration of effect without reducing its activity.

Fluphenazine Decanoate is administered by deep intramuscular injection into the gluteal muscle. A test dose of 12.5 mg (6.25 mg in the elderly) is given, then after 4-7 days, 12.5-100 mg is repeated at intervals of 14-35 days, adjusted according to response. It is not recommended for children.

Fluphenazine reverses the antihypertensive effects of Guanethidine, Methyldopa, and Clonidine. It also causes lithium toxicity by interacting with it. Antacids may reduce the bioavailability of phenothiazines. Additive CNS depressant effects are produced with alcohol, barbiturates, hypnotics, sedatives, opiates, and antihistamines.

Fluphenazine Decanoate oily injection is contraindicated in patients with hypersensitivity to the drug. It is also contraindicated in comatose or severely depressed states, blood dyscrasias, liver disease, pregnancy (3rd trimester), and lactation.

The side effects include tardive dyskinesia, sedation, mental confusion, hypotension, hyperprolactinaemia leading to galactorrhoea and amenorrhoea in women, loss of libido, impotence and sterility in males. Also include allergic reactions, cholestatic jaundice, corneal and lens deposits, and skin pigmentation. Other potential adverse reactions are agranulocytosis and neuroleptic malignant syndrome.

The safety for the use of Fluphenazine decanoate during pregnancy has not yet been established; therefore, the possible hazards should be weighed against the potential benefits when administering this drug to pregnant patients.

Special precaution should be practiced in the presence of convulsive disorders, hepatic, renal, cerebrovascular, respiratory and cardiovascular diseases. Precaution should also be observed in cases of phaeochromocytoma, bone marrow suppression, and elderly or debilitated patients.

Symptoms of overdose may include muscle weakness, an irregular heart rhythm, and breathing difficulty.

Phenothiazine drugs

Store in a cool (below 30°C) and dry place, away from light. Keep out of the reach of children.