SIDE EFFECTS: See also Warning section. Drooling, drowsiness, dizziness, lightheadedness, headache, shaking (tremor), vision problems (e.g., blurred vision), and weight gain may occur. Many of these effects (especially drowsiness) lessen as your body gets used to the medication. If any of these effects persist or worsen, contact your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Constipation may occur when using clozapine, and can lead to very serious complications. To help prevent constipation, maintain a diet adequate in fiber, drink plenty of water, and exercise. If you become constipated, tell your doctor right away - and ask whether regular use of a laxative (such as an osmotic or stimulant type) is necessary while using clozapine. This medication may rarely make your blood sugar rise, which can cause or worsen diabetes. Tell your doctor right away if you have symptoms of high blood sugar such as increased thirst/urination. If you already have diabetes, check your blood sugar regularly as directed and share the results with your doctor. Your doctor may need to adjust your diabetes medication, exercise program, or diet. This drug may also cause significant weight gain and a rise in your cholesterol (or triglyceride) levels. These effects, along with diabetes, may increase your risk for developing heart disease. Discuss the risks and benefits of treatment with your doctor. Tell your doctor right away if you have any serious side effects, including: facial/muscle twitching, seizures, uncontrollable movements, interrupted breathing during sleep, trouble urinating. Get medical help right away if you have any very serious side effects, including: severe dizziness, fainting, mental/mood changes, difficulty breathing with exercise, sudden weakness, pain/redness/swelling of the arms/legs, persistent nausea/vomiting, stomach/abdominal pain, yellowing of eyes/skin. This medication may rarely cause a very serious condition called neuroleptic malignant syndrome (NMS). Get medical help right away if you have any of the following symptoms: fever, muscle stiffness/pain/tenderness/weakness, severe tiredness, severe confusion, sweating, fast/irregular heartbeat, dark urine, signs of kidney problems (such as change in the amount of urine). A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: See also Warning and Side Effects sections. Before taking clozapine, tell your doctor or pharmacist if you are allergic to it or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this medication, tell your doctor or pharmacist your medical history, especially of: history of blood disorders (such as leukemia, low white blood cell count), bowel problems (such as paralytic ileus, irritable bowel syndrome ), breathing problems, diabetes/family history of diabetes, high cholesterol/triglyceride levels, glaucoma, heart problems, kidney problems, liver problems, obesity/family history of obesity, seizures, difficulty urinating (for example, due to enlarged prostate), breathing trouble during sleep (sleep apnea). Clozapine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can rarely cause serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that need medical attention right away. The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may affect the heart rhythm. Before using clozapine, tell your doctor or pharmacist of all the drugs you take and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death). Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using clozapine safely. This drug may make you dizzy or drowsy or blur your vision. Alcohol or marijuana can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana. Tell your doctor if you are a descendent of Ashkenazi Jews because you may be at a higher risk for a drop in your white blood cells. Before having surgery, tell your doctor or dentist that you are using this medication. Liquid products or dissolving tablets may contain sugar and/or aspartame. Liquid products may also contain alcohol. Caution is advised if you have diabetes, liver disease, phenylketonuria (PKU), or any other condition that requires you to limit/avoid these substances in your diet. Ask your doctor or pharmacist about using this product safely. Older adults may be more sensitive to the side effects of this drug, especially constipation, trouble urinating, drowsiness, dizziness, lightheadedness, and QT prolongation (see above). Drowsiness, dizziness, and lightheadedness can increase the risk of falling. During pregnancy, this medication should be used only when clearly needed. Babies born to mothers who have used this drug during the last 3 months of pregnancy may rarely develop symptoms including muscle stiffness or shakiness, drowsiness, feeding/breathing difficulties, or constant crying. If you notice any of these symptoms in your newborn especially during their first month, tell the doctor right away. Since untreated mental/mood problems (such as schizophrenia, schizoaffective disorders) can be a serious condition, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately discuss with your doctor the benefits and risks of using this medication during pregnancy. This medication may pass into breast milk and have undesirable effects on a nursing infant. Breast feeding is not recommended while taking clozapine. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. A product that may interact with this drug is: metoclopramide. Other medications can affect the removal of clozapine from your body, which may affect how clozapine works. Examples include fluvoxamine, rifamycins (such as rifabutin, rifampin), saquinavir, St. John's wort, drugs used to treat seizures (such as carbamazepine, phenytoin), among others. Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana, drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine). Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely. Cigarette smoking decreases blood levels of this medication. Tell your doctor if you smoke or if you have recently stopped smoking.

OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.