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, dronedarone, an H₁ antagonist (eg, astemizole, terfenadine), nilotinib, propafenone, sodium oxybate (GHB), or tetrabenazine.

Contact your doctor or health care provider right away if any of these apply to you.

Some medical conditions may interact with Haldol. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you have the blood disease porphyria, low white blood cell levels, electrolyte problems (eg, low blood magnesium, low blood potassium), or high or low blood pressure
• if you have a history of dementia, Alzheimer disease, seizures, thyroid problems, or neuroleptic malignant syndrome (NMS)
• if you have heart problems or irregular heartbeat (eg, QT prolongation), or if a member of your family has a history of these conditions
• if you have had high blood prolactin levels or a history of certain types of cancer (eg, breast, pancreas, pituitary), or if you are at risk for breast cancer
• if you are dehydrated, drink alcohol, or if you are regularly exposed to extreme heat.

Some medicines may interact with Haldol. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Certain antiarrhythmics (eg, amiodarone, disopyramide, dronedarone, flecainide, procainamide, quinidine, sotalol), certain antipsychotics (eg, iloperidone, paliperidone, ziprasidone), arsenic, bepridil, chloroquine, cisapride, dofetilide, dolasetron, domperidone, droperidol, gadobutrol, H₁ antagonists (eg, astemizole, terfenadine), halofantrine, kinase inhibitors (eg, lapatinib, nilotinib), macrolides or ketolides (eg, erythromycin, telithromycin), maprotiline, methadone, phenothiazines (eg, thioridazine), pimozide, propafenone, certain quinolones (eg, moxifloxacin) or tetrabenazine because the risk of serious heart-related side effects may be increased
• Lithium because the risk of unexpected toxic effects, including weakness, severe tiredness, confusion, or unusual muscle movements, may be increased
• Tramadol because the risk of seizures may be increased
• Azole antifungals (eg, itraconazole) because they may increase the risk of Haldol's side effects
• Rifampin because it may decrease Haldol's effectiveness.
• Carbamazepine because side effects of Haldol may be increased or the effectiveness of Haldol may be decreased
• Anticoagulants (eg, warfarin) or sodium oxybate (GHB) because their actions and the risk of their side effects may be increased by Haldol.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Haldol may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information:

• 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 possible 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.
• Do NOT use more than the recommended dose without checking with your doctor.
• 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.
• 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 lower the ability of your body to fight infection. Avoid contact with people who have colds or infections. Tell your doctor if you notice signs of infection like fever, sore throat, rash, or chills.
• Haldol may increase the amount of a certain hormone (prolactin) in your blood. Symptoms may include enlarged breasts, missed menstrual period, decreased sexual ability, or nipple discharge. Contact your doctor right away if you experience any of these symptoms.
• 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.
• Lab tests, including complete blood cell counts, may be performed while you use Haldol. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lap appointments.
• Use Haldol with caution in the elderly; they may be more sensitive to its effects, especially uncontrolled muscle movements.
• Haldol should not be used in children younger 3 years; safety and effectiveness in these children have not been confirmed.
• 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 breastfeed while taking Haldol.

All medicines may cause side effects, but many people have no, or minor, side effects.

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

Constipation; diarrhea; dizziness; drowsiness; dry mouth; headache; loss of appetite; nausea; restlessness; stomach upset; trouble sleeping.

Seek medical attention right away if any of these severe side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blurred vision or other vision changes; confusion; dark urine; decreased sexual ability; decreased urination; difficulty speaking or swallowing; drooling; enlarged breasts; excessive or unusual sweating; fainting; fast or irregular heartbeat; fever, chills, or persistent sore throat; hallucinations; mental or mood changes (eg, abnormal thinking, agitation, anxiety, depression); missed menstrual period or other menstrual changes; nipple discharge; prolonged, painful erection; rigid or stiff muscles; seizures; severe or persistent dizziness, headache, or vomiting; shuffling walk; uncontrolled muscle movements (eg, of the arms, legs, tongue, jaw, cheeks; tremors; twitching); yellowing of the skin or eyes.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.