Do not use Haldol if:

• you are allergic to any ingredient in Haldol;
• you are in a coma, have Parkinson disease, or have severe central nervous system depression;
• you are taking dofetilide, an H1 antagonist (e.g., astemizole, terfenadine), or sodium oxybate (GHB).

• Haldol may cause drowsiness, dizziness, or blurred vision. These effects may be worse if you take it with alcohol or certain medicines. Use Haldol with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
• Do not drink alcohol or use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using Haldol ; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.
• Haldol may cause you to become sunburned more easily. Avoid the sun, sunlamps, or tanning booths until you know how you react to Haldol. Use a sunscreen or wear protective clothing if you must be outside for more than a short time.
• Do not become overheated in hot weather or while you are being active; heatstroke may occur.
• Tell your doctor or dentist that you take Haldol before you receive any medical or dental care, emergency care, or surgery.
• Neuroleptic malignant syndrome (NMS) is a possibly fatal syndrome that can be caused by Haldol . Symptoms may include fever; stiff muscles; confusion; abnormal thinking; fast or irregular heartbeat; and sweating. Contact your doctor at once if you have any of these symptoms.
• Some patients who take Haldol may develop muscle movements that they cannot control. This is more likely to happen in elderly patients, especially women. The chance that this will happen or that it will become permanent is greater in those who take Haldol in higher doses or for a long time. Muscle problems may also occur after short-term treatment with low doses. Tell your doctor at once if you have muscle problems with your arms; legs; or your tongue, face, mouth, or jaw (eg, tongue sticking out, puffing of cheeks, mouth puckering, chewing movements) while taking Haldol.
• Diabetes patients - Haldol may affect your blood sugar. Check blood sugar levels closely. Ask your doctor before you change the dose of your diabetes medicine.
• Haldol may rarely cause a prolonged, painful erection. This could happen even when you are not having sex. If this is not treated right away, it could lead to permanent sexual problems such as impotence. Contact your doctor right away if this happens.
• Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Haldol while you are pregnant. Haldol is found in breast milk. Do not breast-feed while taking Haldol.

Check with your doctor if any of these most common side effects persist or become bothersome:

• blurred vision; constipation; diarrhea; dizziness; drowsiness; dry mouth; headache; loss of appetite; nausea; stomach upset; trouble sleeping.

• severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); confusion; decreased urination; difficulty speaking or swallowing; drooling; excessive or unusual sweating; fainting; fast or irregular heartbeat; fever; hallucinations; mental or mood changes (e.g., abnormal thinking, agitation, anxiety, depression); prolonged, painful erection; rigid or stiff muscles; seizures; severe or persistent dizziness, headache, or vomiting; shuffling walk; uncontrolled muscle movements (e.g., of the arms, legs, tongue, jaw, cheeks; twitching; tremors); vision problems or changes; yellowing of skin or eyes.

Haldol is to be used only by the patient for whom it is prescribed. Do not share it with other people.
If your symptoms do not improve or if they become worse, check with your doctor.