Jeffrey Panko NP Psychiatry · Patient education
Clozapine
Clozaril / Versacloz / Generic oral formulations
A guide for adults taking clozapine.
Follow the directions on your prescription and your provider's recommendations.
Formulations: Tablets, dissolving tablets, and oral suspension have formulation-specific instructions. Treatment starts at a low dose and increases gradually.
What it is used for
Clozapine treats schizophrenia that has not responded adequately to other antipsychotics. It also reduces recurrent suicidal behavior in people with schizophrenia or schizoaffective disorder when that risk is substantial.
How it works
It acts at several dopamine, serotonin, and other receptors. Its benefits and side-effect pattern differ from other antipsychotics, including important effects on blood cells, the heart, and bowel movement.
What to expect over time
Some symptoms improve earlier than others. Changes in hallucinations, mood, or organized thinking often develop over several weeks. Track practical goals, such as regular sleep and daily activities, and report side effects or limited benefit.
Taking your medication
- Follow the dose schedule exactly. Shake and measure suspension according to its instructions.
- If doses are missed, contact the clinic before restarting; even a short interruption may require a lower restart dose. Never double.
- Do not resume your usual dose after two or more missed days. A full restart dose can cause dangerous low blood pressure or collapse.
- Follow the agreed constipation-prevention plan and keep blood-test appointments.
When to get help
Emergency symptoms. Get urgent emergency assessment for chest pain, breathlessness, collapse, a seizure, or fever with stiffness and confusion. Severe abdominal pain, swelling, vomiting, or constipation with inability to pass gas can indicate a bowel emergency.
Prompt medical advice. Contact the clinic the same day for fever, sore throat, or infection symptoms, and promptly for reduced bowel movements or excessive sedation. Do not wait for a routine visit.
If you feel unsafe or have thoughts of self-harm, call 911 or go to an emergency department.
Possible side effects
- Sleepiness, dizziness, or increased saliva
- Constipation, which can become serious
- Increased appetite, weight, blood sugar, or lipids
- Fast pulse or fever requiring assessment
Keeping track of treatment
Some side effects resolve with time; others may require a change of medication. Discuss persistent or bothersome side effects with your provider.
ANC blood tests monitor infection-fighting white cells. The U.S. REMS program was removed, but recommended ANC monitoring continues. Follow the schedule in your treatment plan.
Track bowel movements. Heart assessment and sometimes clozapine levels are important when symptoms, infection, or interacting medicines change.
If you take too much
For a suspected overdose, call Poison Control at 1-800-222-1222 immediately, even if you feel well. Call 911 for a seizure, collapse, trouble breathing, or inability to wake.
Before you start
Discuss low blood counts, heart disease, seizures, severe constipation or bowel disease, diabetes, and liver or kidney problems. Antipsychotics carry increased mortality risk in older adults with dementia-related psychosis.
Discuss pregnancy, pregnancy plans, and breastfeeding with your provider. Treatment decisions should consider both the medication and the condition being treated.
Medicines and interactions
Review all your medications with your provider, including over-the-counter medicines and supplements. Have new medications checked before taking them.
Tell your provider immediately if smoking changes or you develop a significant infection; clozapine levels may rise. Major changes in caffeine intake also matter.
Fluvoxamine, ciprofloxacin, carbamazepine, medicines that lower blood counts, and drugs that increase seizure risk need particular review. Anticholinergic medicines can worsen dangerous constipation.
Everyday tips
Keep a bowel record and refill plan.
Tell every prescriber that you take clozapine before an antibiotic or other new medication is started.
Your questions answered
Are blood tests still needed after REMS ended?
Yes. Ending the administrative program did not remove the risk of severe neutropenia. Continue the ANC schedule your provider recommends.
Why is restarting different?
Tolerance to some cardiovascular effects is lost quickly. A lower dose and retitration may be needed after an interruption.
Storage and safety
Keep medication in its labeled container, away from excess heat and moisture and out of reach of children and pets. Do not share it. Ask a pharmacy about disposal of unused medication.
Sources
About this information
Educational handout; does not replace your prescription or provider's recommendations.
Educational inclusion does not mean this medication or its indications are treated at this practice. Review the guide for your exact product with your prescriber or pharmacist.