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Olanzapine

Medication atypical antipsychotic mental health
Aka: Zyprexa
Brands seen in Singapore: Zyprexa, Zyprexa Zydis, Onzapin, Olankline, Olanzapine STADA
Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.
How to use
What it’s for
HealthHub: schizophrenia and bipolar mood symptoms
When to take
HealthHub: once daily, with or without food
Take with
Water · NHS: alcohol can make you sleepy or unsteady
Pros & cons
Pros
  • SG label: acute and maintenance use in schizophrenia
  • HealthHub: may be taken with or without food
  • SG label: plain and orodispersible tablets in SG
Cons
  • NHS: sleepiness, weight gain, dizziness, constipation
  • HealthHub: can worsen blood sugar control in diabetes
  • NHS: it may take days or weeks before symptoms improve
Sources
  1. HSA — Listing of Registered Therapeutic Products (data.gov.sg open dataset, 5,511 rows, cached in full and filtered locally) · read 2026-08-27
    what it says
    “All 21 registered olanzapine products read 'Prescription Only' and every one is a 5 mg or 10 mg oral tablet — ZYPREXA · ZYPREXA ZYDIS · Onzapin · OLANKLINE · Olanzapine STADA · OLANCOR · TOLANZ ODT · JUBREXA”
  2. National Drug Formulary (SG, MOH) — ZYPREXA TABLET 10 MG [SIN09410P], approved indications and posology · read 2026-08-27
    what it says
    “indicated for the acute and maintenance treatment of schizophrenia … daily dosage may subsequently be adjusted on the basis of individual clinical status within the range 5–20 mg/day … The recommended starting dose for olanzapine is 10 mg/day”
  3. HealthHub (National Medication Information workgroup, SG) — Olanzapine: what is this medication for · read 2026-08-27
    what it says
    “Olanzapine belongs to a class of medications known as atypical (second-generation) antipsychotics. It is used to treat and prevent return of symptoms in Schizophrenia … It can be used to treat symptoms in bipolar disorder”
  4. HealthHub — Olanzapine: how should I take or use this medication · read 2026-08-27
    what it says
    “Olanzapine should be taken with or without food. Olanzapine is available as orodispersible tablets … Olanzapine needs to be taken regularly for a few weeks before you can feel its full benefits.”
  5. HealthHub — Olanzapine: what precautions should I take · read 2026-08-27
    what it says
    “You have diabetes. Olanzapine may sometimes worsen blood sugar control in diabetes … You are smoking or have any changes to your smoking habits. Smoking may decrease the amount of Olanzapine that stays in your body.”
  6. NHS — About olanzapine (brand name: Zyprexa), Key facts · read 2026-08-27
    what it says
    “Olanzapine does not work straight away. It may take several days, or even weeks, for some of your symptoms to start improving … Drinking alcohol with olanzapine can make you feel sleepy or unsteady”
  7. NHS — Side effects of olanzapine · read 2026-08-27
    what it says
    “These common side effects of olanzapine may affect up to 1 in 10 people … Feeling sleepy in the day … Putting on weight or an increase in your appetite … Feeling dizzy … Rash … Constipation”
  8. NHS — Who can and cannot take olanzapine · read 2026-08-27
    what it says
    “tell your doctor before starting to take it if you have: … a heart problem, including an irregular heartbeat … had a stroke … had a blood clot … Parkinson's disease dementia … diabetes epilepsy … glaucoma”
  9. NHS — Taking olanzapine with other medicines and herbal supplements · read 2026-08-27
    what it says
    “carbamazepine, a medicine for epilepsy fluvoxamine, used to treat depression ciprofloxacin, an antibiotic medicines that make you feel calm or sleepy … Cannabidiol (also known as CBD) might affect how olanzapine works”
  10. NHS — Dosage and how to take olanzapine · read 2026-08-27
    what it says
    “Most people feel better with daily doses of 5mg to 20mg … Take olanzapine once a day, at the same time each day. You can take it with or without food.”
  11. US FDA label — ZYPREXA (olanzapine) oral, section 2.1 Schizophrenia, via openFDA · read 2026-08-27
    what it says
    “Olanzapine is not indicated for use in doses above 20 mg/day.”
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Updated 2026-08-29. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.