Common uses of Olanzapine
Olanzapine is an atypical antipsychotic prescribed primarily for schizophrenia and bipolar I disorder. In schizophrenia, it helps reduce positive symptoms (hallucinations, delusions), calms agitation, and supports improvement in negative symptoms such as social withdrawal. In bipolar I disorder, it treats acute manic or mixed episodes and can be used alone or with mood stabilizers for maintenance to reduce relapse risk. In some cases, it is used off-label for severe agitation associated with psychosis or mood disorders when rapid control is necessary.
The medicine works by balancing neurotransmitters—mainly dopamine and serotonin—in key brain circuits involved in perception, motivation, and mood. Compared with older antipsychotics, olanzapine has a lower risk of certain movement disorders but carries a higher risk of metabolic side effects. Clinical decisions weigh symptom control against risks, with ongoing monitoring to optimize long-term outcomes.
Dosage and direction
Dosing is individualized. For schizophrenia, typical starting doses are 5–10 mg once daily, titrated to a usual range of 10–20 mg daily based on response and tolerability. For acute mania or mixed episodes in bipolar I disorder, common starting doses are 10–15 mg once daily; adjustments are made in 5 mg increments at intervals of at least 24 hours. Many patients stabilize between 10 and 20 mg daily. Older adults and those sensitive to side effects may start at 2.5–5 mg. Olanzapine can be taken with or without food, preferably at the same time each day.
For acute agitation associated with schizophrenia or bipolar I disorder, short-acting intramuscular olanzapine may be used in a controlled clinical setting. Doses typically range from 2.5–10 mg per injection, with careful spacing and a maximum daily limit (often not exceeding 30 mg total per day, including oral formulations). A long-acting injectable (LAI) olanzapine formulation is available for maintenance treatment; it is administered by a healthcare professional on a scheduled basis and may require observation after injection due to rare post-injection delirium/sedation events.
Do not change your dose, frequency, or route without medical guidance. Because relapse can occur if stopped abruptly, any discontinuation should be gradual under clinician supervision to minimize withdrawal symptoms and symptom recurrence.
Forms and administration
Olanzapine is available as standard tablets, orally disintegrating tablets (ODTs) that dissolve on the tongue without water, short-acting intramuscular injections for acute agitation, and long-acting injections for maintenance therapy. Swallow tablets whole with water; for ODTs, ensure dry hands, peel the blister carefully, and place the tablet on the tongue to dissolve. Do not split ODTs. Long-acting injections are clinic-administered only. Adherence tools—such as reminders or blister packs—can help keep dosing on schedule.
Precautions
Metabolic effects are the major precaution. Olanzapine can cause weight gain, elevated blood glucose (including new-onset diabetes), and dyslipidemia. Baseline and periodic monitoring is recommended: weight/BMI, waist circumference, fasting glucose or A1C, and lipid panel. Nutrition counseling and physical activity meaningfully reduce risk; early attention to modest weight changes can prevent larger gains.
Olanzapine may cause sedation, orthostatic hypotension, and anticholinergic effects (dry mouth, constipation, blurred vision). Use caution with activities requiring alertness until you know how you respond. Rise slowly from sitting or lying positions to minimize dizziness. Maintain hydration and avoid overheating, as antipsychotics can impair body temperature regulation, increasing heat-related illness risk.
Serious but uncommon risks include neuroleptic malignant syndrome (fever, muscle rigidity, confusion, autonomic instability), tardive dyskinesia (involuntary movements), severe hyperglycemia with ketoacidosis, seizures (use caution in seizure disorders), and blood dyscrasias. Seek immediate medical care if you experience high fever, severe muscle stiffness, confusion, uncontrolled movements, or signs of severe infection.
Boxed warning: Elderly patients with dementia-related psychosis treated with antipsychotic drugs have an increased risk of death; olanzapine is not approved for this population. In patients with depression, the combination product with fluoxetine carries additional antidepressant-class warnings about suicidality in younger individuals; closely monitor mood and behavior changes.
Pregnancy and breastfeeding: Use only if the potential benefit justifies the potential risk. Discuss family planning and pregnancy goals with your clinician. Olanzapine passes into breast milk; if used while breastfeeding, monitor the infant for sedation, feeding difficulties, or abnormal weight gain. Pediatric and adolescent use requires specialist oversight; growth, metabolic parameters, and movement symptoms should be monitored closely.
Contraindications
Olanzapine is contraindicated in patients with known hypersensitivity to olanzapine or any formulation components (e.g., prior anaphylaxis, angioedema, severe rash). Use extreme caution or consider alternatives in individuals with narrow-angle glaucoma risk, significant hepatic impairment, severe cardiovascular disease, untreated sleep apnea with marked sedation risk, history of neuroleptic malignant syndrome, or a high seizure propensity. In patients with diabetes or strong metabolic risk, use only with rigorous monitoring and lifestyle management.
Possible side effects
Common side effects include sleepiness/sedation, increased appetite, weight gain, dry mouth, constipation, dizziness, orthostatic hypotension, and mild tremor or restlessness (akathisia). Laboratory changes may show increased blood sugar and lipids, mildly elevated liver enzymes, and sometimes elevated prolactin. Many effects are dose-related and improve with careful titration, timing doses in the evening, hydration, fiber intake, and regular exercise.
Less common but serious side effects include severe hyperglycemia, diabetic ketoacidosis, seizures, significant liver injury, blood dyscrasias (e.g., neutropenia), arrhythmias, tardive dyskinesia, and neuroleptic malignant syndrome. Rare hypersensitivity reactions (e.g., DRESS) have been reported. If you develop severe confusion, chest pain, rapid heartbeat, fainting, uncontrollable movements, high fever, or a widespread rash, seek urgent care.
Drug interactions
Central nervous system depressants (alcohol, benzodiazepines, opioids, sedating antihistamines) can add to olanzapine’s sedation and respiratory-depressant effects; avoid or limit alcohol and use caution combining with sedatives. Antihypertensives may potentiate orthostatic hypotension. Dopamine agonists (e.g., levodopa) may have reduced effectiveness when used with antipsychotics.
Metabolic interactions involve CYP1A2 primarily: strong inhibitors (e.g., fluvoxamine, ciprofloxacin) can raise olanzapine levels—dose reductions may be needed. Inducers (e.g., carbamazepine, smoking tobacco) can lower levels and efficacy—dose increases may be required under supervision. Use caution with agents that prolong QT interval, although olanzapine has relatively low QT risk. Always provide your clinician and pharmacist a complete list of prescription medicines, OTC products, and supplements to screen for interactions.
Use in special populations
Older adults may be more sensitive to sedation, orthostatic hypotension, and anticholinergic effects; start low and titrate slowly. In individuals with hepatic impairment, conservative dosing and liver function monitoring are prudent. Smokers may require higher doses due to CYP1A2 induction; conversely, stopping smoking can increase drug exposure—notify your clinician if your smoking status changes. Adolescents may gain weight more rapidly; emphasize nutrition and activity, and monitor growth and metabolic markers closely.
Missed dose
If you miss a dose, take it as soon as you remember unless it is close to the time for your next dose. If it is near the next scheduled dose, skip the missed dose and resume your regular schedule. Do not double up to catch up. For long-acting injections, contact your clinic promptly to reschedule; maintaining the injection window reduces relapse risk.
Overdose
Overdose symptoms may include marked sedation or coma, agitation or delirium, rapid heartbeat, low blood pressure, respiratory depression, anticholinergic effects (dry mouth, blurred vision), extrapyramidal symptoms, and cardiac rhythm changes. This is a medical emergency. Call emergency services and, in the U.S., contact Poison Control at 1-800-222-1222 for immediate guidance. Management is supportive: airway protection, cardiovascular monitoring, IV fluids, treatment of agitation or extrapyramidal effects, and temperature regulation. Activated charcoal may be considered in early presentations by healthcare professionals.
Storage
Store tablets and orally disintegrating tablets at room temperature (generally 20–25°C/68–77°F), protected from moisture and excessive heat. Keep ODTs in the original blister until use; handle with dry hands. Do not freeze injectable products; they are stored and administered by healthcare professionals. Keep all medications out of reach of children and pets, and dispose of unused or expired medicine according to local guidance or pharmacy take-back programs.
U.S. sale and prescription policy
In the United States, olanzapine is a prescription-only medication. You generally cannot legally buy Olanzapine without prescription from retail or online pharmacies. Safe access requires evaluation by a licensed clinician who can diagnose, determine appropriateness, and provide ongoing monitoring for efficacy, side effects, and drug interactions. Be cautious with websites offering to sell antipsychotics without a prescription; they may be unsafe, counterfeit, or unlawful.
HealthSouth Rehabilitation Hospital of Tallahassee offers a legal and structured path to therapy within its care programs: patients receiving clinician-directed treatment can be administered or supplied olanzapine under medical orders without needing to present a personal “take-home” prescription at a retail pharmacy. This supervised access is compliant with U.S. regulations and is not the same as public sale without a prescription. Outside of such supervised settings, a valid prescription from a licensed prescriber is required. To explore your options, contact your clinician or the hospital directly to discuss evaluation, insurance coverage, and safe, compliant access to treatment.
