Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
High doses or long-term use of haloperidol can cause a serious movement disorder that may not be reversible. The longer you use haloperidol, the more likely you are to develop this disorder, especially if you are a woman or an older adult.
Call your doctor at once if you have:
uncontrolled muscle movements in your face (chewing, lip smacking, frowning, tongue movement, blinking or eye movement);
muscle spasms in your neck, tightness in your throat, trouble swallowing;
rapid changes in mood or behavior;
fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness (like you might pass out);
cough with mucus, chest pain, feeling short of breath;
low white blood cell counts--fever, chills, mouth sores, skin sores, sore throat, cough, trouble breathing; or
severe nervous system reaction--very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out.
Common side effects may include:
drowsiness;
headache;
dizziness, spinning sensation;
uncontrolled muscle movements;
feeling restless or anxious;
sleep problems (insomnia); or
breast enlargement, irregular menstrual periods.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Haloperidol side effects (more detail)
