Search strategies-Use of anticholinergic agents for haloperidol extrapyramidal side effects. A systematic review.

The antipsychotic drugs are caused by dopamine blockade in the nigrostriatal pathway and can be distressing and disabling for patients. Anticholinergic agents are commonly used to treat or prevent extrapyramidal symptoms by restoring the balance between dopamine and acetylcholine in the brain. Anticholinergics are drugs that block the action of acetylcholine, a neurotransmitter involved in various functions of the nervous system. These drugs are used to treat some side effects of antipsychotics, such as haloperidol, which can cause extrapyramidal symptoms, such as involuntary movement disturbances.The most used anticholinergics, such as biperiden, trihexyphenidyl, tropicamide, and procyclidine, are primarily used to treat the extrapyramidal side effects induced by some antipsychotics. These drugs act on the muscarinic receptors of acetylcholine, which are found in the striatum, an area of the brain involved in movement control. In this way, anticholinergics help restore the balance between dopamine and acetylcholine and improve symptoms such as tremors, rigidity, bradykinesia, parkinsonism, dystonia, and akathisia. However, anticholinergics can also have side effects for patients who take them along with antipsychotics, common side effects of anticholinergic medications include, blurred vision, constipation, urinary retention, cognitive impairment, delirium, dry mouth, increased salivation, loss of appetite, diarrhea, heartburn, nausea, vomiting, difficulty falling or staying asleep, and lack of energy. These effects may be more severe in older people or people with other illnesses. Therefore, the use of anticholinergics for haloperidol-induced extrapyramidal symptoms should be based on the type, severity, and duration of extrapyramidal symptoms, as well as the patient's age, and comorbidities.