As with all anticholinergics such as procyclidine, cautious prescribing is indicated in patients pre-disposed to glaucoma or with existing angle-closure (narrow angle) glaucoma, obstructive disease of the gastro-intestinal tract and those with urinary symptoms associated with prostatic hypertrophy.
In a proportion of patients undergoing neuroleptic treatment, tardive dyskinesias will occur. While anticholinergic agents do not cause this syndrome, when given in combination with neuroleptics they may reduce the threshold at which the dyskinesias appear in patients pre-disposed to the abnormality. In such individuals, subsequent adjustment of neuroleptic therapy or reduction in anti-cholinergic treatment should be considered.
Patients with mental disorders occasionally experience a precipitation of a psychotic episode when procyclidine is administered for the treatment of the extrapyramidal side effects of neuroleptics.
Elderly patients especially those on high doses of anticholinergics may be more susceptible to the adverse events associated with such therapy (see Undesirable Effects). Specifically the elderly patient may be particularly vulnerable to central nervous system disturbances such as confusion, impairment of cognitive function and memory, disorientation and hallucinations. These effects are usually reversible on reduction or discontinuation of anticholinergic therapy.
There is no specific information available concerning the use of procyclidine hydrochloride in patients with impairment of renal or hepatic function. However, since procyclidine is metabolised in the liver and excreted via the urine care should be exercised when administering procyclidine to patients with impairment of renal or hepatic function
Procyclidine should not be withdrawn abruptly as rebound parkinsonian symptoms may occur.
Abuse
Procyclidine, along with other anticholinergic drugs, has the potential to be abused. Although the cases of abuse are rare, physicians should exercise caution in prescribing Procyclidine to patients with symptoms that may not be genuine.
Excipient Warnings
• Benzyl Alcohol – This medicine contains 0.26mg benzyl alcohol in each 5ml. Benzyl alcohol may cause allergic reactions. High volumes should be used with caution and only if necessary, especially in subjects with liver or kidney impairment because of the risk of accumulation and toxicity (metabolic acidosis).
• Ethanol – This medicine contain 0.05mg of alcohol (ethanol) in each 5ml. The amount in 5ml of this medicine is equivalent to less than 1ml beer and 1ml wine. The small amount of alcohol in this medicine will not have any noticeable effects.
• Liquid Maltitol (E965) - Patients with rare hereditary problems of fructose intolerance should not take this medicine.
• Methyl and Propyl parahydroxybenzoates (E218 and E216) – May cause allergic reactions (possibly delayed).
• Propylene Glycol (E1520) - This medicine contains 113mg of propylene glycol in each 5ml.
• Sodium – This medicine contains less than 1 mmol sodium (23mg) per 5ml, that is to say essentially 'sodium-free'.