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SAPHRIS

Last Updated: January 07, 2010

Manufacturer:

Schering, a div.of Merck & Co.

Pharmacological Class:

Atypical antipsychotic (dibenzo-oxepino pyrrole)

Active Ingredient(s):

Asenapine 5mg, 10mg; sublingual (SL) tabs.

Indication(s):

For the acute treatment of: 1) schizophrenia; 2) manic or mixed episodes associated with bipolar I disorder.

Pharmacology:

Although the precise mechanism of action of asenapine in the treatment of psychosis and bipolar disorder is not known, it may be due to its antagonistic effects at dopamine D₂ and serotonin 5-HT_2A and related receptor sites.

Clinical Trials:

The efficacy of asenapine in treating schizophrenia was evaluated in three placebo-controlled and active-controlled 6-week studies in adults with schizophrenia who were having an acute exacerbation. Two of the studies indicated a superior efficacy to placebo for asenapine. In one of these trials, asenapine 5mg twice daily was statistically superior to placebo on a Positive and Negative Syndrome Scale. In the second trial, two fixed doses of asenapine (5mg or 10mg twice daily) were compared to placebo. The 5mg twice daily dose was shown to be superior to placebo on the PANSS total score, and the 10mg twice daily dose did not show any added benefit and was not significantly better than placebo.

Two 3-week placebo-controlled and active-controlled studies were conducted in patients with bipolar I disorder with an acute manic or mixed episode, with or without psychosis. The Young Mania Rating Scale was used to assess manic symptoms, along with a Clinical Global Impression-Bipolar Scale. Asenapine was dosed initially at 10mg twice daily, and could be reduced to 5mg twice daily starting on day 2. In both trials, the study drug was shown to be statistically superior to placebo on both rating scales.

Legal Classification:

Adults:

Do not crush, chew, or swallow; do not eat or drink for 10 min after administration. Allow tablet to dissolve on tongue completely. Schizophrenia: 5mg twice daily. Bipolar disorder: 10mg twice daily; if adverse effects occur, may reduce to 5mg twice daily. Reevaluate periodically.

Children:

Not recommended.

Precaution(s):

Avoid in congenital long QT syndrome, cardiac arrhythmias. Severe hepatic impairment: not recommended. Discontinue if neuroleptic malignant syndrome occurs; consider discontinuing if tardive dyskinesia occurs. Cardio- or cerebrovascular disease. Pre-existing low WBCs or history of leukopenia/neutropenia; monitor CBCs during 1^st few months of treatment; discontinue if WBCs decline. Diabetes risk factors (obtain baseline fasting blood sugar).Monitor for hyperglycemia. History of seizures. Exposure to extreme heat. Dysphagia. Write Rx for smallest practical amount. Elderly (not for dementia-related psychosis). Pregnancy (Cat.C). Nursing mothers: not recommended.

Interaction(s):

Avoid drugs that can prolong QT interval (eg, Class 1A or Class III antiarrhythmics, ziprasidone, chlorpromazine, thioridazine, moxifloxacin, alcohol). Potentiates antihypertensives. Potentiated by fluvoxamine. Caution with other CNS drugs, drugs that are CYP2D6 substrates /inhibitors, drugs that cause orthostatic hypotension, and drugs with anticholinergic activity.

Adverse Reaction(s):

Akathisia, oral hypoesthesia, somnolence, dizziness, extrapyramidal effects, GI upset; orthostatic hypotension, syncope, QT prolongation, hyperglycemia, weight gain, hyperprolactinemia.