Haldol Warnings and Precautions (Cont.)

• There have been reports of sudden death in people taking Haldol, most likely due to a dangerous irregular heart rhythm (arrhythmia) called QT prolongation. This problem is more likely in people with low potassium levels in the blood (hypokalemia) or other electrolyte imbalances. It is also more likely in people with long QT syndrome (who are prone to QT prolongation arrhythmias).

• Haldol can cause a life-threatening condition called neuroleptic malignant syndrome (NMS). Some symptoms of NMS include:

• A high fever
• Stiff muscles
• Confusion
• An irregular pulse or blood pressure
• A fast heart rate (tachycardia)
• Sweating
• An irregular heart rhythm (arrhythmia).

Tell your healthcare provider right away if think you might have NMS.

• Haldol can cause tardive dyskinesia, a condition involving unusual, uncontrollable body or face movements. The condition can become permanent (even if Haldol is stopped). The best way to prevent it from becoming permanent is to tell your healthcare provider right away if you notice any abnormal movements (including abnormal movements of the tongue) while taking Haldol.
   
• There have been cases of pneumonia (some of which have proven fatal), possibly due to Haldol. If you have symptoms of pneumonia -- such as a cough, chest pain, and a fever -- let your healthcare provider know right away.
   
• Haldol can impair your mental or physical abilities to drive a car or operate heavy machinery. Make sure you know how Haldol affects you before you do any activities that require mental concentration or physical coordination.
   
• Haldol can cause a drop in blood pressure (hypotension). This can cause a person to have lightheadedness or dizziness, or to faint. Tell your healthcare provider if you have any of these symptoms when standing. Hypotension can be especially dangerous in people with heart disease or congestive heart failure (CHF). Combining alcohol with Haldol can also increase the risk of hypotension (see Alcohol and Haldol).
   
• Haldol may increase the risk of seizures in some people. Before starting Haldol, tell your healthcare provider if you have epilepsy or a history of seizures.
   
• Haldol can cause a "switch" to depression in people with bipolar disorder.
   
• Haldol can cause dangerous side effects in people with an uncontrolled, overactive thyroid (hyperthyroidism). If you have thyroid problems, be sure to talk with your healthcare provider before taking Haldol.
   
• Haldol is considered a pregnancy Category C medication. This means that it may not be safe to take during pregnancy. Be sure to talk with your healthcare provider about the risks and benefits of using Haldol during pregnancy (see Haldol and Pregnancy).
   
• Haldol passes through breast milk. Therefore, if you are breastfeeding or plan to start breastfeeding, be sure to talk with your healthcare provider about using Haldol (see Haldol and Breastfeeding for more information).
   
• Haldol can interact with certain other medications (see Haldol Drug Interactions).