synthetic anticholinergic agent

procyclidine hydrochloride

Procyclidine Hydrochloride BP 5mg per tablet

Tablet

Kemadrin is indicated for the treatment and symptomatic relief of all forms of Parkinson's disease e.g. idiopathic (paralysis agitans), postencephalitic and arteriosclerotic disease.

Kemadrin is also indicated for the control of extrapyramidal symptoms induced by neuroleptic drugs including pseudo-parkinsonism, acute dystonic reactions and akathisia.

The variation in optimum dosage from one patient to another should be taken into consideration by the physician.

Dosage in adults:-

Parkinson's disease:-

Treatment is usually started at 2.5mg procyclidine three times per day, increasing by 2.5 to 5mg per day at intervals of two or three days until the optimum clinical response is achieved.

The usual maintenance dose to achieve optimal response is 15 to 30 mg procyclidine per day.

Addition of a fourth dose before retiring has been seen to be beneficial in some patients. Doses up to 60mg procyclidine have been well tolerated, and at the discretion of the attending physician dosing to this level may be appropriate.

In general younger patients or those with postencephalitic parkinsonism may require higher doses for a therapeutic response than older patients and those with arteriosclerotic parkinsonism.

Kemadrin may be combined with levodopa or amantadine in patients who are inadequately controlled on a single agent.

Neuroleptic-induced extrapyramidal symptoms:-

Treatment is usually initiated at 2.5mg procyclidine three times per day increasing by 2.5mg daily until symptoms are relieved.

The effective maintenance dose is usually 10 to 30mg procyclidine per day.

After a period of 3 to 4 months of therapy, KEMADRIN should be withdrawn and the patient observed to see whether the neuroleptic-induced extra-pyramidal symptoms recur.

If this is the case KEMADRIN should be reintroduced to avoid debilitating extra-pyramidal symptoms. Cessation of treatment periodically is to be recommended even in patients who appear to require the drug for longer periods.

The use of Kemadrin in this age group is not recommended.

Elderly patients may be more susceptible than younger adults to the anticholinergic effects of Kemadrin and a reduced dosage may be required.

Kemadrin is contra-indicated in individuals with known hypersensitivity to any component of the preparation, untreated urinary retention, closed angle glaucoma and gastro-intestinal obstruction.

As with all anticholinergics the benefit/risk ratio should be assessed when prescribing Kemadrin in patients with existing angle-closure (narrow angle) glaucoma or those considered to be predisposed to glaucoma. Cautious prescribing is also indicated in patients predisposed to 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 exacerbate the symptoms of tardive dyskinesia or reduce the threshold at which these symptoms appear in predisposed patients. In such individuals subsequent adjustment of neuroleptic therapy or reduction in anticholinergic 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. 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 impaired 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.

Kemadrin should not be withdrawn abruptly as rebound parkinsonian symptoms may occur.

Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.

Abuse

Kemadrin, along with other anticholinergic drugs, has the potential to be abused. Although the cases of abuse are rare, physicians should exercise caution in prescribing Kemadrin to patients with symptoms that may not be genuine.

Monoamine oxidase inhibitors or drugs with anticholinergic properties, such as amantadine, memantine, antihistamines, phenothiazines, tricyclic and related antidepressants, clozapine, disopyramide and nefopam may increase the anticholinergic action of procyclidine.

The use of drugs with cholinergic properties, such as tacrine, may reduce the therapeutic response to Kemadrin. Furthermore, drugs with anticholinergic properties may antagonise the effect of parasympathomimetic agents.

The concomitant use of procyclidine with some neuroleptics for the treatment of extrapyramidal symptoms has been associated with a reduction in neuroleptic plasma concentrations. However this reduction is unlikely to be associated with a significant reduction in clinical effect.

Drugs with anticholinergic properties may decrease salivation causing dry mouth and, in theory, may reduce the absorption and therefore the therapeutic effect of sublingual or buccal nitrate tablets.

Anticholinergics, including procyclidine, may reduce the efficacy of levodopa by increasing gastric emptying time, resulting in enhanced gastric degradation.

The effect of anticholinergics such as procyclidine may antagonise the gastrointestinal effects of cisapride, domperidone and metoclopramide.

Procyclidine may potentiate the vagolytic effects of quinidine.

Anticholinergics may reduce the absorption of ketoconazole.

Exposure to high environmental temperature and humidity in association with a phenothiazine/anticholinergic drug regimen has rarely resulted in hyperpyrexia.

Daily administration of paroxetine increases significantly the plasma levels of procyclidine. If anticholinergic effects are seen, the dose of procyclidine should be reduced.

For this preparation there is no modern clinical documentation which can be used as support for determining the frequency of adverse reactions.

The main undesirable effects are those to be expected from any anticholinergic agent – these are generally reversible on reducing the dosage.

With high doses of procyclidine dizziness, mental confusion, impaired cognition and memory, disorientation, anxiety, agitation and hallucinations may occur.

Laboratories Genopharm

(POM)

15 February 2012