How should I taper off Zyprexa (olanzapine)?

Tablets can be split for graduated reductions. Metabolic burden (weight, lipids, glucose) often improves during taper. Rebound histaminergic insomnia and cholinergic rebound are predominant withdrawal features. Monitor for dopamine supersensitivity psychosis. Slow hyperbolic taper essential, particularly after long-term use. Available 2.5 mg tablets support stepwise reductions; aqueous suspension may be needed for sub-mg increments. Monitor for supersensitivity psychosis and EPS during reductions.

Zyprexa Tapering Guide

Q: What are the withdrawal symptoms of Zyprexa (olanzapine)?

Common withdrawal symptoms of Zyprexa (olanzapine) include: rebound insomnia, anxiety, nausea, psychosis risk, sweating. Symptom severity varies by individual, dose, and duration of use.

olanzapine

Atypical AntipsychoticFDA 1996

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Boxed Warning

Increased mortality in elderly patients with dementia-related psychosis. Post-injection delirium/sedation syndrome with extended-release IM formulation (Zyprexa Relprevv).

Overview

Olanzapine is an atypical antipsychotic approved for schizophrenia and bipolar disorder (manic/mixed episodes, maintenance, and bipolar depression in combination with fluoxetine). It is effective but carries the highest metabolic risk among atypical antipsychotics.

Common Doses

2.5mg, 5mg, 10mg, 15mg, 20mg

Formulations

Tablets: 2.5mg, 5mg, 7.5mg, 10mg, 15mg, 20mg; Orally disintegrating tablets (Zydis): 5mg, 10mg, 15mg, 20mg; Intramuscular injection: 10mg; Extended-release injection (Zyprexa Relprevv): 210mg, 300mg, 405mg

Pregnancy

Category C (risk cannot be ruled out)

Mechanism of Action

Antagonist at dopamine D1–D4, serotonin 5-HT2A/2C/3/6, histamine H1, muscarinic M1–M5, and alpha-1 adrenergic receptors. The broad receptor profile contributes to efficacy but also drives significant weight gain and metabolic effects.

Taper Notes

Tablets can be split for graduated reductions. Metabolic burden (weight, lipids, glucose) often improves during taper. Rebound histaminergic insomnia and cholinergic rebound are predominant withdrawal features. Monitor for dopamine supersensitivity psychosis.

Maudsley Deprescribing Guidance

Slow hyperbolic taper essential, particularly after long-term use. Available 2.5 mg tablets support stepwise reductions; aqueous suspension may be needed for sub-mg increments. Monitor for supersensitivity psychosis and EPS during reductions.

Common Withdrawal Symptoms

rebound insomniaanxietynauseapsychosis risksweating

Interactions & Safety

Drug Interactions

CYP1A2 inhibitors (fluvoxamine, ciprofloxacin) increase olanzapine levels — reduce dose
CYP1A2 inducers (smoking, carbamazepine) decrease olanzapine levels — dose adjustment needed (smokers need higher doses)
CNS depressants — additive sedation

Food Interactions

Food does not significantly affect absorption
Avoid alcohol (additive CNS depression)

Contraindications

Known hypersensitivity to olanzapine

Toxicity

Significant metabolic syndrome (weight gain, hyperglycemia, diabetes, dyslipidemia — highest among atypical antipsychotics). Sedation. Orthostatic hypotension. Tardive dyskinesia. NMS rarely.

Pharmacokinetics

ADME Profile

Absorption

Well absorbed after oral administration. Bioavailability ~60% due to first-pass metabolism. Tmax ~6 hours. Food does not significantly affect absorption.

Distribution

~1000 L (~14 L/kg)

Metabolism

Extensively metabolized hepatically via CYP1A2 (primary) and CYP2D6 via glucuronidation and oxidation. Major metabolites (10-N-glucuronide and 4'-N-desmethyl) are inactive.

Elimination

Renal (~57%) and fecal (~30%). Approximately 7% excreted unchanged in urine.

Protein Binding

~93%

Clearance

~26 L/hr (apparent oral clearance)

Build Zyprexa taper plans in minutes

TaperMeds turns these protocols into prescriber-ready taper schedules with hyperbolic dose curves, symptom tracking, and patient handouts — for the clinicians supervising the taper.