There are many possible side effects with antipsychotics, which vary according to the specific drug. Some of the most common include:

• Extrapyramidal (disruption in the nerves and muscles controlling movement and coordination) side effects, including:
  
  
• Parkinsonian side effects. Symptoms that resemble Parkinson’s disease (progressive disorder of the nervous system) such as slowed movements, decreased facial expression, resting tremor and a shuffling gait.
  
  
• Dystonic symptoms. These involve sustained muscle spasms, usually of the neck or shoulders, which can be painful and frightening.
  
  
• Akathisia. Intense feeling of restlessness. This can sometimes be confused with psychotic agitation.
  
  
• Anticholinergic (affecting the autonomic nervous system, which controls involuntary body functions such as circulation and intestinal functions) side effects. These symptoms may be very mild or severe, depending on the medication, and may include:
  
  
• Dry mucous membranes (especially mouth and eyes).
  
  
• Blurred vision (especially when viewing items at close range).
  
  
• Intestinal slowing (constipation).
  
  
• Difficulty urinating.
  
  
• Sedation.
  
  
• Sexual dysfunction.
  
  
• Rapid heart rate (tachycardia).
  
  
• Antiadrenergic (blocking or reducing the effects of adrenaline in the body) side effects. These may include orthostatic hypotension. When a person stands, blood pressure drops dramatically. This can lead to transient lightheadedness and a potential fall and injury.
  
  
• Tardive dyskinesia. Involuntary movements that may include tongue thrusting, repetitive chewing, jaw swinging and/or facial grimacing. This is more common with conventional antipsychotics and usually occurs only if the medication is taken for extended periods of time on an ongoing basis.

Other side effects of antipsychotic medications may include weight gain, a rise in blood sugar levels (occurs primarily with olanzapine use), seizures, hyperthermia (excessive body heat) and agranulocytosis (a blood disorder that causes a drop in white blood cells, which help fight infection; associated with clozapine use).

Research also suggests that certain antipsychotics (e.g., risperidone) may ibe associated with an ncreased risk of developing benign (noncancerous) pituitary tumors. In very rare instances, patients may develop neuroleptic malignant syndrome (NMS). NMS is characterized by fever, confusion and rigidity. If not treated promptly, it can lead to coma and death.

Patients who experience certain side effects should contact their physician immediately because medication changes may be necessary. These side effects include:

• Confusion
• Falls
• Inability to urinate
• Prolonged or severe constipation
• Rash
• High fever (this may be due to agranulocytosis or NMS)
• Involuntary movements
• Jaundice (yellowing of the skin, including eyes)
• Severe sedation
• Severe restlessness
• Muscle spasms

Patients sometimes use an antipsychotic side effects checklist (ASC) to monitor side effects. ASC is a screening tool developed by mental health professionals to help patients document common side effects associated with antipsychotic medications. Symptoms commonly tracked include:

• Loss of energy and drive
• Muscles that tremble or shake
• Weight change
• Dry mouth
• Insomnia