Clozapine brands and prices in Pakistan

About Clozapine

Clozapine is an antipsychotic medicine from the 'atypical' group. It changes the activity of certain natural chemicals in the brain. It is a specialist medicine: it is used only when other antipsychotic medicines have not worked or have caused side effects that could not be managed. Because it can sometimes cause a dangerous drop in the white blood cells that fight infection, everyone taking it needs regular blood tests, and it is started and monitored by a specialist mental health team or clozapine clinic.

Who should not take it, or should take care

• Do not take it if you are allergic to clozapine, have ever had a low white blood cell count caused by a medicine, or had to stop clozapine before because of a serious side effect.
• It must not be used by people with bone marrow disease, epilepsy that is not controlled, severe kidney, liver or heart disease, myocarditis, a blocked or paralysed bowel (paralytic ileus), or with medicines that lower white blood cells.
• It is not used in people who have had long-acting antipsychotic (depot) injections, or whose mental illness is caused by alcohol or drugs.
• Tell your doctor if you have epilepsy or have had a seizure or head injury, constipation or bowel problems, glaucoma, prostate or urine problems, diabetes, high cholesterol, heart, lung, kidney or liver disease, low or high blood pressure, a heart rhythm problem (long QT), or a history of blood clots.
• Older people may be more likely to get some side effects, such as dizziness and falls.
• Tell your doctor about your smoking and how much coffee, tea or cola you drink. Starting or stopping smoking, or switching to e-cigarettes or nicotine replacement, can change the level of clozapine in your blood.
• Tell your doctor before any operation or long period of not moving, because of the risk of blood clots.
• Pregnancy: get advice from your doctor if you are pregnant or planning a baby, and tell them straight away if you become pregnant. Babies exposed late in pregnancy may have shaking, stiffness, sleepiness or breathing and feeding problems.
• Breastfeeding: the UK leaflet says not to breastfeed, as clozapine passes into breast milk.
• Periods may return after switching to clozapine, so use effective contraception if you do not want to become pregnant.

Medicines and drinks that can interact

• Medicines that can lower white blood cells or affect the bone marrow, such as carbamazepine, co-trimoxazole, chloramphenicol, penicillamine and cancer chemotherapy
• Medicines that raise or lower clozapine levels, such as fluvoxamine, some other antidepressants, erythromycin, ketoconazole, rifampicin, omeprazole, cimetidine, phenytoin and some HIV medicines
• Medicines that cause sleepiness, such as benzodiazepines, strong painkillers and antihistamines
• Lithium, valproate and other medicines for mental health
• Medicines that affect blood pressure, heart rhythm or the bowel, including medicines that cause constipation
• Warfarin and digoxin
• Hormonal contraceptives
• St John's wort (a herbal remedy)
• Alcohol: avoid it, as it can make side effects worse
• Smoking and caffeine: changes in either can change how clozapine works
• Always tell every doctor, dentist and pharmacist that you take clozapine before starting or stopping any medicine.

Always tell your doctor and pharmacist about every medicine, supplement and herbal product you take.

Using it safely

• Go to every blood test. You cannot be given clozapine without an up-to-date blood result, so contact your team quickly to rebook if you miss one.
• Tell your team about any fever or sign of infection straight away.
• Tell your team about constipation early and ask them how to prevent and treat it.
• If you miss a dose, take it when you remember unless the next one is nearly due. Never take two doses together.
• If you have stopped taking it, even for a short time, contact your doctor or clozapine team before starting again. The dose may need to be built up again slowly because your body loses its tolerance.
• Do not stop taking it suddenly without talking to your doctor. Stopping can cause withdrawal effects and your symptoms may come back.
• Do not drive, use machines, swim or climb until you know how it affects you, because it can cause sleepiness, fainting or fits.
• Get up slowly from sitting or lying down to avoid dizziness and falls.
• Your weight, blood sugar and blood fats may also be checked during treatment.
• Keep it in its original container out of the reach of children, and return unused medicine to your pharmacy or clinic.

Common questions

Why do I need so many blood tests?
Clozapine can occasionally cause a big drop in neutrophils, the white blood cells that fight infection. This can lead to a serious infection. Regular blood tests pick up changes early. The risk is highest in the first months but never disappears completely, so tests continue throughout treatment.

Does smoking affect clozapine?
Yes. Smoking lowers the level of clozapine in the blood. If you stop or start smoking, or switch to e-cigarettes or nicotine replacement, tell your doctor first, because your dose may need to change.

Why is constipation so important with clozapine?
Clozapine slows down the gut. Mild constipation is common, but it can turn into a serious bowel blockage that can be fatal. Tell your team as soon as you notice it, and get urgent help for severe tummy pain, swelling or vomiting.

Can I drink alcohol while taking clozapine?
It is best to avoid alcohol. It can make sleepiness and other side effects worse.

When will clozapine start to work?
It can take some time to feel the full benefit. Keep taking it and keep going to your appointments, and talk to your team if you are worried.

Prepared from the sources listed by the MedInfoBase team. General information, not medical advice: it gives no doses. Your doctor or pharmacist decides the medicine and dose for you.