Olanzapine

Class

• Thienobenzodiazepine atypical antipsychotic

Indications

• Acute and maintenance treatment of schizophrenia and related psychotic disorders

• Acute treatment of manic or mixed episodes of bipolar 1 disorder

• Psychotic symptoms in dementia

• Intramuscular olanzapine is indicated for the rapid control of agitated patients

Administration/Absorption

• Oral

  • 40% of the dose metabolized before reaching the systemic circulation

• IM

Dosage

Distribution

• 93% protein bound

• VOD 1000 L

Mechanism

• Combination of antagonism at:

  • D2 receptors in the mesolimbic pathway

    • Relieves positive symptoms

  • 5HT2A receptors in the frontal cortex

    • Relieves negative symptoms

Excretion

• Metabolized by the cytochrome P450 system isoenzymes 1A2 and 2D6

• Only 7% excreted unchanged in urine

• Half life 21 - 54 hr

Side effects

• Serious:

  • tardive dyskinesia,

  • neuroleptic malignant syndrome

• Other:

  • akathisia

  • dry mouth

  • dizziness

  • irritability

  • sedation

  • insomnia

  • constipation

  • urinary retention

  • orthostatic hypotension

  • weight gain

  • increased appetite

  • runny nose

  • impaired judgment, thinking, and motor skills

  • impaired spatial orientation

  • impaired responses to senses

  • seizures

  • trouble swallowing

  • dental problems and discolouration of teeth

  • missed periods

  • problems with keeping body temperature regulated

  • apathy, lack of emotion

  • Endocrine side effects have included hyperprolactinemia, hyperglycemia, and diabetes mellitus

  • Brain Zaps

  • Auditory Hallucinations[22]

Interactions

Contraindications