Skip to main content

What you need to know about the special drug called Clozapine

What you need to know about the special drug called Clozapine

Have you or someone you know been prescribed Clozapine by your doctor? If so, you may be a little apprehensive or curious about this medication. This is not a commonly prescribed medication. Most of the time, doctors decide to prescribe this medication when other medications fail to control the symptoms. So, let's talk about it in a very simple and friendly way today.

Simply put, what is Clozapine?

Clozapine is a medication used to treat schizophrenia , a mental illness. It is usually used when other medications have failed or are not tolerated.

Think of our brain as a city with a traffic jam. Messages need to go back and forth. These messages are carried by chemicals like dopamine and serotonin . In a state like schizophrenia, these chemicals are out of balance. It's like the traffic lights in the city are not working. Clozapine works by restoring that imbalance. It belongs to a class of drugs called antipsychotics .

Things you need to tell your doctor before starting this medication

This is very important. It is important for your safety to inform your doctor about any medical conditions you have. If you have any of the following, be sure to tell your doctor before starting the medication.

  • Bowel blockage or frequent constipation
  • Cancer
  • Forgetfulness diseases such as dementia
  • Diabetes
  • Glaucoma condition
  • Difficulty controlling muscles
  • Heart disease or elevated cholesterol levels
  • Having an irregular heartbeat or having had a stroke in the past
  • Kidney or liver disease
  • Decreased blood cell levels (white blood cells, red blood cells)
  • Low blood pressure
  • Parkinson's disease
  • Phenylketonuria (PKU)
  • Prostate problems
  • Seizures
  • Tobacco use (if you smoke)
  • Difficulty urinating or swallowing
  • Having had an allergic reaction to Clozapine or any other medicine or food
  • If you are trying to get pregnant, are pregnant, or are a breastfeeding mother

How exactly do you use this medicine?

This is not like a regular pill. This is a disintegrating pill that dissolves when placed in the mouth.. That means when you put it in your mouth, it dissolves automatically, and then you can swallow it. You don't have to drink it with water, but there's no problem with drinking water.

  • Before or after food?: This medicine can be taken before or after food. It doesn't matter.
  • Take it on time: Take the exact dose, exactly as your doctor tells you. Do not take more than the prescribed amount.
  • Do not stop suddenly: This is the most important thing. Never stop taking this medicine suddenly without consulting your doctor. Doing so can cause serious side effects. If you need to stop taking the medicine, your doctor will gradually reduce the dose.
  • About the pill: Do not take the pill out of the packet until just before you need to take it. If your doctor tells you to take half a pill, do not save the remaining half for later use. Destroy it.

Important: This medicine has been prescribed for you only. Never share it with anyone else.

What to do if you miss a dose of medication?

If you miss a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and take your next dose at the scheduled time. Never take two doses at the same time. If you miss more than two days of medication, do not start again at the same dose. Call your doctor immediately for advice.

What if I take too much medicine?

If you think you have taken too much medicine, immediately call the National Poisons Information Centre at the Colombo National Hospital , or go to the Emergency Treatment Unit (ETU) of the nearest hospital.

Things to keep in mind when taking this medicine

Clozapine is a medication that should always be taken under medical supervision, so be careful about these things.

1. Mandatory blood test: This is the most important thing. When you start taking the medicine, you need to have a blood test once a week . This checks your white blood cell count. If your blood count is good after 6 months, your doctor may ask you to do this test every two weeks. Your name will also be recorded in a national register, to make sure you have not had a severe allergy to this medicine.

2. Skin reactions: Some people may develop serious skin reactions several weeks after starting this medicine. If you develop red or purple spots on your skin along with fever, body aches, and then blisters and the skin starts to peel off, tell your doctor right away.

3. Constipation:This medicine can cause stomach upset. If you are not having regular bowel movements, or if you are having fewer than three bowel movements a week, tell your doctor. If you have stomach pain along with bloating, nausea, or vomiting, it may be serious. So drink plenty of fluids.

4. Dizziness and drowsiness: This medicine may affect your balance and alertness. Therefore , avoid driving or operating machinery until you know how this medicine affects you. To reduce the risk of dizziness and fainting, stand up straight when getting up from a chair or bed. Drinking alcohol can increase these side effects.

5. Blood sugar levels: This medicine may increase blood sugar levels. If you have diabetes, talk to your doctor about this and get the necessary advice.

6. Smoking: If you smoke, tell your doctor. If you stop smoking, your medication dosage may need to be adjusted.

7. Body temperature: This medicine may cause problems in controlling body temperature. The ability to tolerate extreme cold or extreme heat may decrease. Therefore, wear warm clothes on very cold days, be careful of the sun on very hot days, and drink plenty of water.

What are the possible side effects?

Like any medication, this one can have side effects. Some are serious, some are common. It's important to be aware of these.

Side effects that you should report to your doctor immediately
Allergic reactions Skin rash, itching, swelling of the face, lips or tongue.
Symptoms of infection Fever, chills , cough, sore throat.
Heart muscle problems Unusual tiredness, shortness of breath, chest pain, fast or irregular heartbeat, ankle swelling.
High fever and muscle stiffness Symptoms of a serious condition called neuroleptic malignant syndrome may include excessive sweating and confusion.
Stroke symptoms Numbness on one side of the face, arm, or leg, difficulty speaking, difficulty walking, severe headache.
Liver problems (Liver injury) Pain in the upper right side of the stomach, loss of appetite, yellowing of the eyes or skin, dark urine.
Seizures Sudden convulsions.
Uncontrollable movements (EPS) Involuntary movements of body parts, muscle tension, tremors, restlessness.
Side effects that are usually not serious, but should be reported to the doctor if they persist
Dizziness Dizziness
Drowsiness Drowsiness
Spitting out saliva from the mouth Excessive drooling
Headache Headache
Weight gain Weight gain

If you experience any other unusual symptoms not mentioned in this list, tell your doctor about them as well.

Take-Home Message

  • Clozapine is a very effective medication for schizophrenia , but it must be taken under medical supervision.
  • It is mandatory to have weekly blood tests while taking this medication. This is very important for your safety.
  • Do not stop taking the medication suddenly for any reason without your doctor's advice.
  • If you experience any serious side effects such as fever, severe skin rashes, or chest pain, seek medical advice immediately.
  • Be sure to tell your doctor about any other medications you are taking and any illnesses you have.
  • If you have any questions about this medicine, don't hesitate to ask your doctor.

Clozapine, Fazaclo, schizophrenia , antipsychotics, mental health, dopamine, serotonin, side effects, blood test
⚠️ Important: The medical articles and information on Nirogi Lanka are for general awareness only, and are by no means a substitute for professional medical advice, diagnosis, or treatment. For any medical problem you have, consult a qualified physician immediately.

💬 Comments (0)

No comments have been posted yet. Add your comment here for the first time.

Add your comment

Please calculate: 6 + 8 =
What you need to know about the special drug called Clozapine
MedicationsJuly 7, 2026

What you need to know about the special drug called Clozapine

Have you or someone you know been prescribed Clozapine by your doctor? If so, you may be a little apprehensive or curious about this medication. This is not a commonly prescribed medication. Most of the time, doctors decide to prescribe this medication when other medications fail to control the symptoms. So, let's talk about it in a very simple and friendly way today.

Simply put, what is Clozapine?

Clozapine is a medication used to treat schizophrenia , a mental illness. It is usually used when other medications have failed or are not tolerated.

Think of our brain as a city with a traffic jam. Messages need to go back and forth. These messages are carried by chemicals like dopamine and serotonin . In a state like schizophrenia, these chemicals are out of balance. It's like the traffic lights in the city are not working. Clozapine works by restoring that imbalance. It belongs to a class of drugs called antipsychotics .

Things you need to tell your doctor before starting this medication

This is very important. It is important for your safety to inform your doctor about any medical conditions you have. If you have any of the following, be sure to tell your doctor before starting the medication.

  • Bowel blockage or frequent constipation
  • Cancer
  • Forgetfulness diseases such as dementia
  • Diabetes
  • Glaucoma condition
  • Difficulty controlling muscles
  • Heart disease or elevated cholesterol levels
  • Having an irregular heartbeat or having had a stroke in the past
  • Kidney or liver disease
  • Decreased blood cell levels (white blood cells, red blood cells)
  • Low blood pressure
  • Parkinson's disease
  • Phenylketonuria (PKU)
  • Prostate problems
  • Seizures
  • Tobacco use (if you smoke)
  • Difficulty urinating or swallowing
  • Having had an allergic reaction to Clozapine or any other medicine or food
  • If you are trying to get pregnant, are pregnant, or are a breastfeeding mother

How exactly do you use this medicine?

This is not like a regular pill. This is a disintegrating pill that dissolves when placed in the mouth.. That means when you put it in your mouth, it dissolves automatically, and then you can swallow it. You don't have to drink it with water, but there's no problem with drinking water.

  • Before or after food?: This medicine can be taken before or after food. It doesn't matter.
  • Take it on time: Take the exact dose, exactly as your doctor tells you. Do not take more than the prescribed amount.
  • Do not stop suddenly: This is the most important thing. Never stop taking this medicine suddenly without consulting your doctor. Doing so can cause serious side effects. If you need to stop taking the medicine, your doctor will gradually reduce the dose.
  • About the pill: Do not take the pill out of the packet until just before you need to take it. If your doctor tells you to take half a pill, do not save the remaining half for later use. Destroy it.

Important: This medicine has been prescribed for you only. Never share it with anyone else.

What to do if you miss a dose of medication?

If you miss a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and take your next dose at the scheduled time. Never take two doses at the same time. If you miss more than two days of medication, do not start again at the same dose. Call your doctor immediately for advice.

What if I take too much medicine?

If you think you have taken too much medicine, immediately call the National Poisons Information Centre at the Colombo National Hospital , or go to the Emergency Treatment Unit (ETU) of the nearest hospital.

Things to keep in mind when taking this medicine

Clozapine is a medication that should always be taken under medical supervision, so be careful about these things.

1. Mandatory blood test: This is the most important thing. When you start taking the medicine, you need to have a blood test once a week . This checks your white blood cell count. If your blood count is good after 6 months, your doctor may ask you to do this test every two weeks. Your name will also be recorded in a national register, to make sure you have not had a severe allergy to this medicine.

2. Skin reactions: Some people may develop serious skin reactions several weeks after starting this medicine. If you develop red or purple spots on your skin along with fever, body aches, and then blisters and the skin starts to peel off, tell your doctor right away.

3. Constipation:This medicine can cause stomach upset. If you are not having regular bowel movements, or if you are having fewer than three bowel movements a week, tell your doctor. If you have stomach pain along with bloating, nausea, or vomiting, it may be serious. So drink plenty of fluids.

4. Dizziness and drowsiness: This medicine may affect your balance and alertness. Therefore , avoid driving or operating machinery until you know how this medicine affects you. To reduce the risk of dizziness and fainting, stand up straight when getting up from a chair or bed. Drinking alcohol can increase these side effects.

5. Blood sugar levels: This medicine may increase blood sugar levels. If you have diabetes, talk to your doctor about this and get the necessary advice.

6. Smoking: If you smoke, tell your doctor. If you stop smoking, your medication dosage may need to be adjusted.

7. Body temperature: This medicine may cause problems in controlling body temperature. The ability to tolerate extreme cold or extreme heat may decrease. Therefore, wear warm clothes on very cold days, be careful of the sun on very hot days, and drink plenty of water.

What are the possible side effects?

Like any medication, this one can have side effects. Some are serious, some are common. It's important to be aware of these.

Side effects that you should report to your doctor immediately
Allergic reactions Skin rash, itching, swelling of the face, lips or tongue.
Symptoms of infection Fever, chills , cough, sore throat.
Heart muscle problems Unusual tiredness, shortness of breath, chest pain, fast or irregular heartbeat, ankle swelling.
High fever and muscle stiffness Symptoms of a serious condition called neuroleptic malignant syndrome may include excessive sweating and confusion.
Stroke symptoms Numbness on one side of the face, arm, or leg, difficulty speaking, difficulty walking, severe headache.
Liver problems (Liver injury) Pain in the upper right side of the stomach, loss of appetite, yellowing of the eyes or skin, dark urine.
Seizures Sudden convulsions.
Uncontrollable movements (EPS) Involuntary movements of body parts, muscle tension, tremors, restlessness.
Side effects that are usually not serious, but should be reported to the doctor if they persist
Dizziness Dizziness
Drowsiness Drowsiness
Spitting out saliva from the mouth Excessive drooling
Headache Headache
Weight gain Weight gain

If you experience any other unusual symptoms not mentioned in this list, tell your doctor about them as well.

Take-Home Message

  • Clozapine is a very effective medication for schizophrenia , but it must be taken under medical supervision.
  • It is mandatory to have weekly blood tests while taking this medication. This is very important for your safety.
  • Do not stop taking the medication suddenly for any reason without your doctor's advice.
  • If you experience any serious side effects such as fever, severe skin rashes, or chest pain, seek medical advice immediately.
  • Be sure to tell your doctor about any other medications you are taking and any illnesses you have.
  • If you have any questions about this medicine, don't hesitate to ask your doctor.

Clozapine, Fazaclo, schizophrenia , antipsychotics, mental health, dopamine, serotonin, side effects, blood test
⚠️ Important: The medical articles and information on Nirogi Lanka are for general awareness only, and are by no means a substitute for professional medical advice, diagnosis, or treatment. For any medical problem you have, consult a qualified physician immediately.

💬 Comments (0)

No comments have been posted yet. Add your comment here for the first time.

Add your comment

Please calculate: 6 + 8 =