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Olanzapine (Zyprexa)
by Erowid
Olanzapine is a thienobenzodiazapine atypical antipsychotic. It is chemically related to Quetiapine (Seroquel) and Clozapine (Clozaril). Olanzapine is used for reducing psychotic symptoms for medium-length periods (1-8 weeks). Long term usage has not been well studied and because it can take more than a day to reach stable blood levels, it is not often chosen for acute, emergency treatment.
Dose #
Taken orally, 5-20mg per day, starting at 5mg/day and then increased slowly by increments of 5mg per day, giving a week between changes to allow levels to stabilize. Zyprexa brand olanzapine comes in 2.5mg, 5mg, 7.5mg, 10mg, 15mg, and 20mg tablets. The Zyprexa Zydis tablets are an orally disintigrating version for people who have a tendency to spit out their medication.
Price #
No Price
Olanzapine is an unscheduled pharmaceutical available by prescription.
Chemistry #
No Chemistry
Pharmacology #
No Pharmacology
Production #
No Production
History #
No History
Terminology / Slang #
Brand Names:
The Substance:
The Experience:
No common terms known.
The peak plasma concetrations of olanzapine are achieved 6 hours after ingestion. The initial effects of olanzapine are sedation and, possibly, a dry mouth. The antipsychotic effect of olanzapine is not immediately apparent after single dosing. This is likely due to the fact that olanzapine accumulates over the period of a week to a steady state level in the bloodstream. These levels are roughly twice what would occur after a single dose of olanzapine.

Experimentally, olanzapine causes sedation in a a higher percentage of people than quetiapine or clozapine, however it is generally considered less sedating than either of these drugs. This makes olanzapine a very attractive choice for many patients who are bound to antipsychotics.

There is reason to believe that the 5-HT2 antagonism of olanzapine may have an antidepressant effect.

Onset #
As with other antipsychotics, olanzapine is considered quite safe. Nonetheless, there is a small potential for a syndrome known as Neuroleptic Malignant Syndrome (NMS). NMS *has* been reported with olanzapine. Tardive Dyskinesia (potentially irreversible, involuntary, jerking) may develop in patients treated with olanzapine for long periods.

Mental side effects include agitation, akathisia, amnesia, anxiety, dizziness, euphoria, headache, hostility, insomnia, sleepiness, stuttering, akithisia (restlessness of the legs).

Physical side effects include chest pain, edema, hypotension, tachycardia, abdominal pain, constipation, dry mouth, increased appetite, PMS (in women), weight gain, joint pain, rash, fever, and occasional sexual side effects.

  • Carbamazepine reduces the effectiveness of olanzapine.
  • Levodopa's effects may be blocked by the systemic antagonism of olanzapine.