Description

Paxil

PAXIL (paroxetine hydrochloride) is an orally administered psychotropic drug. It is the hydrochloride salt of a phenylpiperidine compound identified chemically as (-)-?trans?-4?R?-(4′-fluorophenyl)-3?S?-[(3′,4′-methylenedioxyphenoxy) methyl] piperidine hydrochloride hemihydrate and has the empirical formula of C 19 H 20 FNO 3 ?HCl?1/2H 2 O. The molecular weight is 374.8 (329.4 as free base).

Paroxetine hydrochloride is an odorless, off-white powder, having a melting point range of 120? to 138?C and a solubility of 5.4 mg/mL in water.

Dosage

Usual Adult Dose:
The administration of paroxetine should be initiated at 20 mg daily. For most patients, 20 mg daily will also be the optimum dose. The therapeutic response may be delayed until the third or fourth week of treatment.

Dose Adjustments:
Based on pharmacokinetic parameters, steady-state paroxetine plasma levels are achieved over a 7 to 14 days interval. Hence, dosage adjustments in 10 mg increments should be made at 1 to 2 week intervals or according to clinician’s judgment.

Dose Range :
For those patients who do not respond adequately to the 20 mg daily dose, a gradual increase in dosage up to 40 mg daily may be considered. The maximum recommended daily dose is 50 mg.

Precautions

Not recommended for use during pregnancy, in nursing mothers, epileptic patients, glaucoma, neuroleptic malignant syndrome, renal or hepatic impairment, activation of mania/hypomania, suicidal tendency, MI or unstable heart disease. Efficacy/safety of combined Paxil and electroconvulsive therapy has not been studied. Hyponatremia (reversible), abnormal bleeding. If a decision is made to stop Paxil therapy, the drug should be gradually withdrawn, as abrupt discontinuation may cause withdrawal symptoms.

Side Effects

Commonly Observed:
The most commonly observed adverse experiences associated with the use of paroxetine and not seen at an equivalent incidence among placebo treated patients were: Nausea, somnolence, sweating, tremor, asthenia, dizziness, dry mouth, insomnia and male sexual dysfunction (primarily ejaculatory delay).