Withdrawal of trihexyphenidyl

Area of Science:

• Pharmacology
• Neuroscience
• Psychiatry

Background:

• Trihexyphenidyl is an anticholinergic used to manage neuroleptic-induced extrapyramidal symptoms.
• The necessity of continuous trihexyphenidyl therapy remains debated.
• Antipsychotic medications can cause significant side effects, including movement disorders.

Purpose of the Study:

• To investigate the effects of trihexyphenidyl withdrawal in patients receiving long-term antipsychotic treatment.
• To identify and characterize a potential withdrawal syndrome associated with trihexyphenidyl discontinuation.

Main Methods:

• A double-blind, placebo-controlled study was conducted on 22 psychiatric patients.
• Patients receiving concurrent antipsychotic and trihexyphenidyl therapy were monitored during withdrawal.
• Key parameters assessed included anxiety, psychotic and extrapyramidal symptoms, salivary flow, vital signs, and sleep duration.

Main Results:

• Trihexyphenidyl withdrawal precipitated a recognizable syndrome.
• This syndrome was characterized by increased anxiety, physical complaints, orthostatic hypotension, and tachycardia.
• Temporary exacerbation of psychotic and extrapyramidal symptoms was observed.

Conclusions:

• The findings support the existence of a trihexyphenidyl withdrawal syndrome.
• Discontinuation of trihexyphenidyl can lead to a transient increase in adverse symptoms.
• This highlights the importance of careful consideration before discontinuing the medication.