How should I taper off Zyprexa (olanzapine)?

Tablets can be split. Weight gain reversal during tapering. Rebound insomnia common. Slow gradual taper essential. Tablets available in small increments (2.5mg). Monitor for supersensitivity symptoms.

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Zyprexa Tapering Guide

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. Weight gain reversal during tapering. Rebound insomnia common.

Maudsley Deprescribing Guidance

Slow gradual taper essential. Tablets available in small increments (2.5mg). Monitor for supersensitivity symptoms.

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.

Sources & References

Zyprexa (olanzapine) information on this page is sourced from peer-reviewed research, regulatory bodies, clinical guidelines, and patient-advocacy organizations.

Encyclopedic & chemical databases

Neutral, high-authority entity references.

Wikipedia entry for olanzapine

Peer-reviewed research

Primary literature cited in this taper guide.

Horowitz MA, Jauhar S, Natesan S, Murray RM, Taylor D 2021 — A method for tapering antipsychotic treatment that may minimize the risk of relapse (Schizophrenia Bulletin)
Tranter R, Healy D 1998 — Antipsychotic withdrawal symptoms: phenomenology and pathophysiology (Journal of Psychopharmacology)
Davies J, Read J 2019 — A systematic review into the incidence, severity and duration of antidepressant withdrawal effects (Addictive Behaviors)

Clinical guidelines

Evidence-based deprescribing and prescribing standards.

Deprescribing-specific resources

Clinician-facing references on tapering protocols.

Royal College of Psychiatrists — Antipsychotics — UK clinical guidance on antipsychotic prescribing and discontinuation
Council for Evidence-Based Psychiatry (CEP UK) — Evidence-based critique of long-term antipsychotic prescribing
Deprescribing.org — Antipsychotic deprescribing algorithm for insomnia and BPSD

Patient-advocacy & lived-experience

Long-running communities documenting withdrawal experience.

Surviving Antidepressants — antipsychotic tapering forum — Community archive of antipsychotic taper experiences
Mad in America — antipsychotic archive — Independent journalism on antipsychotics and withdrawal
Inner Compass Initiative — Withdrawal Project — Peer-led psychiatric drug withdrawal resources
RxISK — adverse drug reaction reporting — Independent database of antipsychotic adverse-effect reports

TaperCommunity does not provide medical advice. Always consult a qualified prescriber before adjusting psychiatric medication.

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)

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