1 What is Clozaril?

Brand: Clozaril, FazaClo, Versacloz

Generic: Clozapine

Clozapine is an antipsychotic drug used for the treatment of severe schizophrenia. This drug has been proposed to antagonize dopamine and serotonin receptors which results to changes some of the chemicals in the brain that are thought to cause schizophrenia. 

This drug is contraindicated to people with dementia. This drug is only available through a restricted program.

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2 What to Know Before Using

Before taking this drug, the risks and benefits for your body should be discussed with your healthcare provider. Inform your healthcare provider for any allergic reactions to these drugs or any other drugs, foods, dyes, preservatives, or animals. 

Carefully read the label of non-prescription drugs for any possible allergic reaction or contraindications. There are no specific data comparing use of this drug in children with use in other age groups. 

Elderly patients require adjustments to the dose of this drug since they are more likely to have constipation, trouble passing urine, uncontrolled movements, or age-related liver, kidney, or heart problems. 

Adverse effects have been reported in animal studies but studies in pregnant women or animals are still inadequate. Studies determining infant risk when taking this drug during breastfeeding are still inadequate. 

Discuss with your healthcare professional the possible risks and benefits before taking this drug while breastfeeding. Drugs should not be taken together to prevent any interactions but in necessary cases inquire your healthcare provider regarding the adjustments in dosage or any other necessary precautions to prevent any unwanted side effects. 

Inform your healthcare professional if you are taking any other drugs such as: 

  • Amifampridine
  • Acebutolol
  • Acetyldigoxin
  • Amitriptyline
  • Amoxapine
  • Arsenic Trioxide
  • Atenolol
  • Bepridil
  • Betaxolol
  • Bevantolol
  • Bisoprolol
  • Carteolol
  • Celiprolol
  • Clomipramine
  • Crizotinib
  • Desipramine
  • Deslanoside
  • Digitalis
  • Digitoxin
  • Digoxin
  • Dilevalol
  • Diltiazem
  • Dofetilide
  • Dothiepin
  • Doxepin
  • Droperidol
  • Esmolol
  • Flecainide
  • Imipramine
  • Ketanserin
  • Levobunolol
  • Levomethadyl
  • Lithium
  • Lofepramine
  • Metildigoxin
  • Metipranolol
  • Metoprolol
  • Mirtazapine
  • Nadolol
  • Nebivolol
  • Nortriptyline
  • Oxprenolol
  • Penbutolol
  • Pindolol
  • Propranolol
  • Protriptyline
  • Sotalol
  • Tertatolol
  • Timolol
  • Trimipramine
  • Verapamil
  • Aceclofenac
  • Acemetacin
  • Alacepril
  • Amtolmetin
  • Guacil
  • Aspirin
  • Benazepril
  • Bromfenac
  • Bufexamac
  • Captopril
  • Celecoxib
  • Choline Salicylate
  • Cilazapril
  • Clonixin
  • Cyclosporine
  • Delapril
  • Dexibuprofen
  • Dexketoprofen
  • Diclofenac
  • Diflunisal
  • Dipyrone
  • Droxicam
  • Enalapril
  • Enalaprilat
  • Etodolac
  • Etofenamate
  • Etoricoxib
  • Felbinac
  • Fenoprofen
  • Fepradinol
  • Feprazo
  • Floctafenine
  • Flufenamic Acid
  • Fluphenazine
  • Flurbiprofen
  • Fosinopril
  • Gossypol
  • Ibuprofen
  • Ibuprofen Lysine
  • Imidapril
  • Indomethacin
  • Ketoprofen
  • Ketorolac, Licorice
  • Lisinopril
  • Lornoxicam
  • Loxoprofen
  • Lumiracoxib
  • Meclofenamate
  • Mefenamic Acid
  • Meloxicam
  • Mepivacaine
  • Moexipril
  • Morniflumate
  • Nabumetone
  • Naloxone
  • Naproxen
  • Nepafenac
  • Niflumic Acid
  • Nimesulide
  • Oxaprozin
  • Oxyphenbutazone
  • Parecoxib
  • Pentopril
  • Perindopril
  • Phenylbutazone
  • Piketoprofen
  • Piroxicam
  • Proglumetacin
  • Propionic Acid
  • Propyphenazone
  • Proquazone
  • Quinapril
  • Ramipril
  • Rofecoxib
  • Salicylic Acid
  • Salsalate
  • Sodium Salicylate
  • Spirapril
  • Sulindac
  • Temocapril
  • Tenoxicam
  • Tiaprofenic Acid
  • Tolfenamic Acid
  • Tolmetin
  • Trandolapril
  • Valdecoxib
  • Warfarin
  • Yohimbine
  • Zofenopril

Intake of specific food or using alcohol or tobacco with magnesium is associated with an increased risk of certain side effects. Your healthcare professional can give you special instructions about the use of food, alcohol, or tobacco. 

Inform your healthcare provider for any other medical problems such as alcohol abuse,  Blood clotting problems, Blood vessel problems, Dehydration, Head injury, Heart  disease,  Hypokalemia, Hypomagnesemia, Hypotension, Hypovolemia, stroke, Bowel problems, Diabetes, Difficult urination, Dyslipidemia, Enlarged prostate, Glaucoma, Hyperglycemia, Liver disease, Neuroleptic malignant syndrome, Seizures, Phenylketonuria, kidney or liver disease.

3 Proper Usage

This drug must be taken exactly as directed by your doctor. To prevent any side effects, take this drug exactly as directed in the label or as prescribed by your healthcare professional.  Follow the instructions in the label or as directed by your healthcare professional. 

You can take this drug with or without food. Make sure your hands are dry before using the disintegrating tablet. Peel back the foil to remove the tablet from the blister pack. Refrain from pushing the tablet through the foil.

The tablet should melt quickly after placing it in your mouth. Use the dosing syringe to measure the accurate amount of drug you will take. Wash the oral syringe with warm water after using it. You will be advised to increase your fluid intake to prevent constipation

The dose of this drug will be variable for different patients. The directions on the label or the prescription by your healthcare professional should be followed. The dosage of this drug you take depends on the medical problem for which you are using this drug.  

Adults with schizophrenia or with suicidal behavior are initially given 12.5 milligrams per day, taken as a single dose or two times per day. The dose must not exceed 900 mg per day. Use and dose in children must be determined by your healthcare professional. 

A missed dose should be taken as soon as possible. However, skip the missed dose and go back to your regular dosing schedule if it is almost time for your next dose. Consult with your healthcare professional first if you miss 2 or more days of clozapine doses. 

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing. Keep out of the reach of children. 

Dispose any outdated or expired drugs and ask your healthcare professional for the proper disposal of the drugs. Throw away any unused drugs 100 days after opening the bottle for the first time.

4 Precautions to Take

Your healthcare provider should closely monitor the effectiveness of this drug as well as check for unwanted effects. Unwanted effects may be screened using blood tests. This drug will be dispensed to you only if your blood tests show that it is safe for you to take it. 

This drug may increase your risk of getting an infection as it can temporarily lower the number of white blood cells in your blood. Avoid any form of contact to people with infections. 

Consult with your healthcare provider immediately if you suspect an infection, or if you have a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination, or symptoms of a heart problem such as chest pain or discomfort, a fast or slow heartbeat, trouble breathing, or fever and chills. 

Refrain from driving, operating machines, swimming, climbing, or do anything else that could be dangerous as this drug may cause drowsiness, blurred vision or convulsions. This drug may cause QT prolongation that may alter you heart rhythm causing you to faint or experience some serious side effects. 

If you experience any symptoms of heart rhythm problems such as fast, pounding, or uneven heartbeats, dizziness, lightheadedness, or fainting, contact emergency medical services immediately. Diabetic patients taking this drug should check their blood and urine sugar levels more often than normal since this drug can elevate the glucose level in your blood. 

Consult with your healthcare professional immediate if you have increased thirst or urination. This drug can cause either wetness or dryness of the mouth. Use sugarless gum or candy, melt bits of ice in your mouth, or use a saliva substitute for temporary relief of mouth dryness. 

Consult with your healthcare professional if your mouth dryness persists for more than 2 weeks as this may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections. 

Consult with your healthcare professional immediately if you experience symptoms of neuroleptic malignant syndrome (NMS) such as convulsions, difficulty with breathing, fast heartbeat, high fever, high or low blood pressure, increased sweating, loss of bladder control, severe muscle stiffness, unusually pale skin, or tiredness. 

Use of this drug in the elderly may cause symptoms of tardive dyskinesia such as lip smacking or puckering, puffing of the cheeks, rapid or worm-like movements of the tongue, uncontrolled chewing movements, or uncontrolled movements of the arms and legs. 

Seek advice from your healthcare professional if you experience symptoms of a liver problem such as pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, unusual tiredness or weakness, or yellow eyes or skin. 

Consult with your healthcare professional before you stop taking drug. Your healthcare might slowly taper the amount you are taking before stopping it completely to prevent the illness from suddenly returning and to decrease the chance of having symptoms such as headache, nausea, vomiting or diarrhea. 

This drug potentiate the effects of alcohol and other central nervous system (CNS) depressants such as antihistamines or medicine for hay fever, other allergies, or colds, sedatives, tranquilizers, or sleeping medicine, prescription pain medicine or narcotics, medicine for seizures or barbiturates, muscle relaxants, or anesthetics, including some dental anesthetics. 

Inform your healthcare professional that you are taking this drug before having surgery or medical tests. Consult with your healthcare professional before taking any other prescription or non-prescription drugs, and herbal or vitamin supplements.

5 Potential Side Effects

Side effects may vary for each individual and prompt medical attention should be given if they occur. 

Inform you healthcare provider immediately if you experience any unusual symptoms such as:

  • blurred vision
  • confusion
  • dizziness,
  • aintness or lightheadedness when getting up suddenly from a lying or sitting position 
  • fainting
  • fast, pounding or irregular heartbeat or pulse
  • fever
  • shakiness in the legs, arms, hands, or feet
  • sleepiness or unusual drowsiness
  • sweating
  • trembling or shaking of the hands or feet
  • unusual tiredness or weakness
  • anxiety 
  • black, tarry stools
  • chest pain
  • chills
  • convulsions
  • cough or hoarseness
  • decrease in the frequency of urination
  • decrease in urine volume
  • difficult or labored breathing
  • difficulty in passing urine
  • discouragement
  • dry mouth
  • feeling sad or empty
  • fever with or without chills
  • frequent strong or increased urge to urinate
  • general feeling of tiredness or weakness
  • headache
  • hyperventilation
  • irritability,
  • lack of appetite
  • loss of bladder control
  • loss of interest or pleasure
  • lower back or side pain
  • muscle spasm or jerking of the arms or legs
  • painful or difficult urination
  • pounding in the ears
  • restlessness or need to keep moving
  • severe or continuing headache
  • shakiness and unsteady walk
  • slurred speech
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • sudden jerky movements of the body
  • sudden loss of consciousness,
  • swollen glands
  • throat discomfort
  • tightness in the chest
  • trouble concentrating
  • trouble sleeping
  • unsteadiness, trembling, or other problems with muscle control or coordination
  • absence of or decrease in movement
  • change in appetite
  • dark urine
  • decreased sexual ability
  • difficult or fast breathing or sudden shortness of breath
  • increased sweating
  • increased thirst
  • increased urination
  • lip smacking or puckering
  • muscle stiffness
  • nausea
  • puffing of the cheeks
  • rapid or worm-like movements of the tongue
  • swelling or pain in the leg
  • uncontrolled chewing movements
  • uncontrolled movements of the arms and legs
  • unusual bleeding or bruising
  • unusually pale skin
  • vomiting
  • weakness
  • yellow eyes or skin
  • abdominal or stomach pain
  • bloating
  • burning
  • crawling
  • itching
  • numbness
  • prickling, pins and needles, or tingling feelings
  • clay-colored stools
  • confusion as to time, place, or person
  • constipation
  • diarrhea
  • epileptic seizure that will not stop feeling that others are watching you or controlling your behavior feeling that others can hear your thoughts
  • feeling, seeing, or hearing things that are not there
  • holding false beliefs that cannot be changed by fact
  • inability to move the eyes
  • increased blinking or spasms of the eyelid
  • indigestion
  • itching or skin rash
  • joint pain
  • light-colored stools
  • muscle twitching
  • pains in the stomach, side, or abdomen, possibly radiating to the back rhythmic movement of the muscles
  • severe mood or mental changes
  • sticking out of the tongue
  • swelling around the eyes
  • swelling of the body or feet and ankles
  • trouble with speaking
  • unpleasant breath odor
  • unusual behavior
  • unusual excitement
  • nervousness or restlessness
  • unusual facial expressions
  • unusual weight gain
  • upper right abdominal or stomach pain
  • vomiting of blood

Some side effects may occur that usually do not need medical attention. As your body adjusts to the drug, these side effects may eventually disappear. Ask your healthcare professional about ways to prevent or reduce some of these side effects. 

If any of the following side effects persists, or are inconvenient, or if you notice any other effects, or if you have any questions about them, consult with your health care professional.

 If any of the following side effects persists, or are inconvenient, or if you notice any other effects, or if you have any questions about them, consult with your health care professional. Report any side effects to the FDA hotline at 1-800-FDA-1088.

6 Related Clinical Trials