American Journal Of Hospital Pharmacy[JOURNAL]

Recent research on the role of clozapine in the treatment of Parkinson's disease and other movement disorders is discussed. Most clinical trials have shown resolution of or improvement in psychotic symptoms accompanying... Recent research on the role of clozapine in the treatment of Parkinson's disease and other movement disorders is discussed. Most clinical trials have shown resolution of or improvement in psychotic symptoms accompanying Parkinson's disease without worsening of parkinsonian symptoms. Adverse effects appear to be mild at dosages of < 100 mg/day; sedation is the most frequent problem. Most of these studies have serious limitations, however; until better studies have been completed, the decision to use clozapine for Parkinson's disease-related psychosis should be made on a case-by-case basis, with thorough evaluation of risks, benefits, and other therapeutic options. Some patients with Parkinson's disease have shown improvement in tremor and other abnormal movements when given clozapine. Clozapine cannot be recommended for treating tardive dyskinesia on the basis of the research done so far; some trials show dramatic resolution of symptoms, others no benefit. Anticholinergics or dopamine-reuptake inhibitors should be considered before clozapine is given to patients with tardive dyskinesia because of clozapine's potential for serious adverse effects. A few patients with Huntington's disease have responded to clozapine, but again no conclusions can be drawn. Clozapine appears to offer no real advantage over haloperidol for treating choreiform movements in Huntington's disease. The frequency of tics in Tourette's syndrome does not seem to be reduced by clozapine. Clozapine has shown some efficacy as a treatment for psychosis and abnormal movements in Parkinson's disease. Results have been less promising for other movement disorders. Further study in larger populations is needed before any definitive conclusions about clozapine's place in movement disorder therapy can be made.

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Venlafaxine: a heterocyclic antidepressant.

Ellingrod VL, Perry PJ

Am J Hosp Pharm · 1994 Dec · PMID 7856622

The pharmacology, pharmacokinetics, and clinical efficacy of venlafaxine hydrochloride, a new antidepressant, are described. Venlafaxine inhibits the reuptake of serotonin, norepinephrine, and, to a lesser extent, dopami... The pharmacology, pharmacokinetics, and clinical efficacy of venlafaxine hydrochloride, a new antidepressant, are described. Venlafaxine inhibits the reuptake of serotonin, norepinephrine, and, to a lesser extent, dopamine. In animal models, it does not significantly inhibit muscarinic, histaminic, or adrenergic receptor activity and does not inhibit monoamine oxidase. Venlafaxine is rapidly absorbed and metabolized in the liver to its active metabolite, O-desmethylvenlafaxine (ODV). Time to peak concentration is one to two hours for the parent compound and four to five hours for ODV. The pharmacokinetics of venlafaxine might be dose-dependent, although pharmacokinetic studies have had conflicting results. The major route of elimination is renal; thus, patients with renal dysfunction may require lower doses. In double-blind, placebo-controlled trials of venlafaxine for maintenance therapy, venlafaxine has shown effective antidepressant activity in severely ill patients with major depression. Antidepressant effectiveness may be apparent within two weeks; this finding needs to be replicated. The dosage is 75-375 mg/day administered in two or three divided doses. The strength of the antidepressant response may be correlated with increasing dosage. Nausea is the most commonly reported adverse drug reaction (ADR). Others include somnolence, dizziness, dry mouth, and sweating. All ADRs have commonly occurred at the beginning of therapy and decreased with time. Overall, venlafaxine is well tolerated. Venlafaxine is as effective as other available antidepressants. It may cause fewer anticholinergic, antihistaminic, and antiadrenergic ADRs and may have a quicker onset of therapeutic action than existing antidepressants.

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