Fluoro butyrophenones

Fluoro butyrophenones - SYNTHESIS AND DRUG PROFILE

a. Haloperidol (Halidol, Hexidol, Cizoren)

Synthesis

Metabolism: It is metabolized by oxidative N-dealkylation. The principal metabolites are oxidative products, such as 4-flurobenzoyl propionic acid and 4-fluro phenylaceturic acid.

Properties and uses: It is useful in the management of psychotic reactions, hostility, and hyperactivity. It is a drug of choice for Tourett’s syndrome. Haloperidol is an effective neuroleptic and also possesses antiemetic properties.

Dose: For restlessness and confusion: Adult 1–3 mg every 8 h. For psychoses: Adult: 0.5–5 mg twice or thrice/ day, may increase up to 100 mg daily in severe or resistant cases. Usual maintenance: 3–10 mg daily. Child: >3 year: Initially, 25–50 μg/kg daily in two divided doses, increased gradually if necessary. Maximum: 10 mg/day.

b. Trifluperidol

Synthesis

Uses: It is used for the treatment of schizophrenia and other psychosis, mania, and short-term adjunctive management of psychomotor agitation and excitement.

c. Droperidol

Synthesis

Properties and uses: It is a white or almost white powder insoluble in water, sparingly soluble in alcohol, freely soluble in dimethylformamide and in methylene chloride. The drug exhibits relatively low therapeutic potency, medium extrapyramidal toxicity, high sedative effect, and above all high hypotensive action. It is frequently used in combination with the nacrotic agents pre-anaesthetically. It is a neuroleptic used as an adjunct to anaesthesia to produce sedation and reduce incidence of nausea and vomiting. Also used as β1 -adrenoceptor agonist α-adrenoceptor agonist.

Assay: Dissolve the sample in a mixture of 1 volume of anhydrous acetic acid and 7 volumes of methyl ethyl ketone. Titrate with 0.1 M perchloric acid, using naphthol benzene solution, and end point is the colour change from orange-yellow to green.

Storage: It should be stored in well-closed airtight container and protected from light.

Dosage forms: Droperidol injection B.P., Droperidol tablets B.P.