Clozapine

Why have I been prescribed Clozapine? 

Clozapine is an antipsychotic, used to treat schizophrenia. It is often effective where other antipsychotics have not helped or one had to stop them due to serious side effects. In schizophrenia, many people hear voices of people talking to them or about them. They may also become suspicious or paranoid. Some people have problems with their thinking and feel that other people can read their thoughts. These are usually called “positive” symptoms. Many people with schizophrenia also experience “negative symptoms”. They feel tired and lacking in energy and can become quite inactive and withdrawn. Clozapine can help both positive and negative symptoms. 

What exactly is Clozapine? 

Clozapine is an antipsychotic. Sometimes it is also known as an atypical or newer generation antipsychotic, because it tends not to  cause some of  the side effects that older generation antipsychotics do (like shaking and other strange movements). Clozapine works in  a different way  and has  other side effects. The brand  or trade name of Clozapine, available  in India is Sizopin, Skizoril, Lozapine, Chrozep among others. 

Is clozapine safe to take? 

Before  the patients start taking Clozapine, their blood has  to be tested,  and they will continue to have regular blood tests. This is because, very rarely, Clozapine can lower  the number of white cells in the blood. White cells are very important in the blood as they fight infection. If you have too few white cells, it  will be harder for  your body to fight off cells in your blood. Only one  or two in every hundred have this bad reaction. It is not related to  the dose of Clozapine that you are taking. If  your blood shows that your white cells are falling down, then Clozapine is stopped. 

It is usually safe to have  Clozapine regularly as prescribed by your psychiatrist, but it doesn’t suit everyone. You should always tell  your doctor if you have: 

• Epilepsy  or glaucoma,  or suffer from liver, heart, kidney  or prostrate trouble 
• If you are taking  any other medication, especially antidepressants, or anti convulsants 
• If you are taking medication from  the pharmacy for colds  or ulcers, especially antihistamines  or cimetidine (Tagamet) 
• If you are pregnant, breast feeding,  or wish to become pregnant 

What is the usual  dose of clozapine? 

The starting dose  is usually 12.5mg per day, which is increased slowly over a few weeks. The usual dose can be anything 300mg and 600mg a day, with the maximum dose being 900mg a day. 

What should I do  if I miss a dose? 

If  you miss  a dose of this medicine, take it as soon as possible. However, if it is almost time for  your next dose, skip the missed  dose and go back  to your regular dosing schedule. Do not double doses. If  you miss 2 or more days of clozapine doses, talk  to your doctor before you start taking it again. You may need to restart this medicine at a lower dose than you were taking before. 

How long will it take before I can see it work? 

Clozapine does  not work straight away. It may  take several  days or even weeks for some of the symptoms to reduce. To begin with, many people find that this medication  will help them feel more relaxed and calm. Later, after two or three weeks, other symptoms should begin to improve. Unfortunately,  you might get some side effects before you start  to feel any better. Most side effects should go away after  a few weeks. 

Are there any side effects of taking clozapine? 

Along  with its needed effects, a medicine  may cause some unwanted effects. Some side effects may not have signs or symptoms that you can see or feel. Clozapine can cause some very serious blood problems. Your doctor will watch for these by doing blood tests every week for 18 weeks, every two weeks for another 18 weeks  and then every four weeks  for as long as you are taking  clozapine and for 4 weeks after  you stop taking it. Please note that not all patients will get all the side effects listed. There may be possibly other side effects. Always consult your psychiatrist about the side effects. 

The most serious adverse reactions experienced with clozapine are agranulocytosis (lowering  of white cell count in  the blood), seizure, cardiovascular effects and fever. The most common side effects are drowsiness, excessive salivation, tachycardia and sedation. 

Contact  your doctor as soon as possible if you develop unusual tiredness  or weakness, fever, sore throat, or other symptoms of infection. These can be symptoms of a very serious blood problem. 

Contact your doctor as soon as possible if you have chest pain  or discomfort, a fast heartbeat, trouble breathing,  or fever  and chills. These can be symptoms  of a very serious problem  with your heart. 

Check with your  doctor immediately  if any of  the following side effects occur: 

More common:    Fast or irregular heartbeat; fever; low blood pressure
    
Less common:    High blood pressure (severe or continuing headache)
    
Rare:    Chest pain or discomfort; chills; convulsions (seizures); cough; difficult or fast breathing or sudden shortness  of breath; fainting; increased sweating;  loss of bladder control; muscle stiffness (severe); sore throat; sores, ulcers, or white spots on lips or  in mouth; swelling  or pain  in leg; trouble breathing;  unusual bleeding  or bruising  or any other change  in blood count, and any unusual tiredness or weakness; unusually pale skin. Check with your doctor as soon as possible if any  of the following side effects occur:
    
More common:  Dizziness, especially when getting up from a lying or sitting position
    
Less common:  Blurred vision; confusion; restlessness or need to keep moving; unusual anxiety, nervousness, or irritability
    
Rare:  Absence of or decrease in movement; decreased sexual ability; high blood sugar    (increased appetite, increased thirst, increased urination, weakness); lip smacking or puckering; liver problems (dark urine, decreased appetite, nausea, vomiting, yellow eyes or skin); mental depression; puffing of cheeks; rapid or worm-like movements of tongue; trembling or shaking; trouble in sleeping; trouble in urinating; uncontrolled chewing movements; uncontrolled movements of arms and legs 

Symptoms of overdose:  Convulsions (seizures); dizziness or fainting; drowsiness (severe) or coma; fast, slow, or irregular heartbeat; hallucinations (seeing, hearing, or feeling things  that are not there); increased watering of mouth (severe); slow, irregular, or troubled breathing; unusual excitement, nervousness, or restlessness
 
Other side effects may occur that  usually do not need medical attention. These side effects may go away during treatment as your body adjusts  to the medicine.  However, check with  your doctor if  any of the following side effects continue  or are bothersome:
    
More common:  Constipation; dizziness or light headedness (mild); drowsiness; headache (mild);    increased watering of mouth; nausea or vomiting; unusual weight gain
   
Less common: Abdominal discomfort or heartburn; dryness of mouth 

Will clozapine interact  with any other medication I am taking? 

Some medications may interact with clozapine while they are being metabolised in the body.  It is always safer to inform your psychiatrist about any other drugs you  may be taking, especially if  you are taking antidepressant medication, anti convulsants  to control seizures/epilepsy, lithium or  if you are  taking medication from the pharmacy  for colds  or ulcers, especially antihistamines or cimetidine (Tagamet) 

What about alcohol? 

It is officially recommended  that people taking clozapine should not drink alcohol. This  is because both alcohol  and clozapine can cause drowsiness, which can lead  to falls or accidents. Alcohol can also make  your psychosis worse. 

What about driving? 

For the above reasons  of drowsiness, it  is safer you do  not drive while you are taking clozapine. 

When  I feel better, can I stop the medication? 

No. If you stop taking clozapine,  your original symptoms may return, although sometimes it may not happen until 2-3 months after you stop clozapine. You  and your psychiatrist should decide together when you can stop  your medication. Most people need to be on clozapine for a long time, even several years. If  you need to stop it, it should be done gradually unless it is urgent that it be stopped abruptly.