Procyclidine hydrochloride ((±)-Procyclidine hydrochlorid)

Anticholinergic medication for antipsychotic-induced tardive dyskinesia

Background: Antipsychotic (neuroleptic) medication is used extensively to treat people with serious mental illnesses. However, it is associated with a wide range of adverse effects, including movement disorders. Because of this, many people treated with antipsychotic medication also receive anticholinergic drugs in order to reduce some of the associated movement side-effects. However, there is also a suggestion from animal experiments that the chronic administration of anticholinergics could cause tardive dyskinesia. Objectives: To determine whether the use or the withdrawal of anticholinergic drugs (benzhexol, benztropine, biperiden, orphenadrine, procyclidine, scopolamine, or trihexylphenidyl) are clinically effective for the treatment of people with both antipsychotic-induced tardive dyskinesia and schizophrenia or other chronic mental illnesses. Search methods: We retrieved 712 references from searching the Cochrane Schizophrenia Group's Study-Based Register of Trials including the registries of clinical trials (16 July 2015 and 26 April 2017). We also inspected references of all identified studies for further trials and contacted authors of trials for additional information. Selection criteria: We included reports identified in the search if they were controlled trials dealing with people with antipsychotic-induced tardive dyskinesia and schizophrenia or other chronic mental illness who had been randomly allocated to (a) anticholinergic medication versus placebo (or no intervention), (b) anticholinergic medication versus any other intervention for the treatment of tardive dyskinesia, or (c) withdrawal of anticholinergic medication versus continuation of anticholinergic medication. Data collection and analysis: We independently extracted data from included trials and we estimated risk ratios (RR) with 95% confidence intervals (CIs). We assumed that people who left early had no improvement. We assessed risk of bias and created a 'Summary of findings' table using GRADE. Main results: The previous version of this review included no trials. We identified two trials that could be included from the 2015 and 2017 searches. They randomised 30 in- and outpatients with schizophrenia in the USA and Germany. Overall, the risk of bias was unclear, mainly due to poor reporting: allocation concealment was not described; generation of the sequence was not explicit; studies were not clearly blinded; and outcome data were not fully reported.Findings were sparse. One study reported on the primary outcomes and found that significantly more participants allocated to procyclidine (anticholinergic) had not improved to a clinically important extent compared with those allocated to isocarboxazid (MAO-inhibitor) after 40 weeks' treatment (1 RCT, n = 20; RR 4.20, 95% CI 1.40 to 12.58; very low quality evidence); that there was no evidence of a difference in the incidence of any adverse effects (1 RCT, n = 20; RR 0.33, 95% CI 0.02 to 7.32; very low quality evidence); or acceptability of treatment (measured by participants leaving the study early) (1 RCT, n = 20; RR 0.33, 95% CI 0.02 to 7.32; very low quality evidence). The other trial compared anticholinergic withdrawal with anticholinergic continuation and found no evidence of a difference in the incidence of acceptability of treatment (measured by participants leaving the study early) (1 RCT, n = 10; RR 2.14, 95% CI 0.11 to 42.52; very low quality evidence).No trials reported on social confidence, social inclusion, social networks, or personalised quality of life - outcomes designated important to patients. No studies comparing either i. anticholinergics with placebo or no treatment, or ii. studies of anticholinergic withdrawal, were found that reported on the primary outcome 'no clinically important improvement in TD symptoms and adverse events'. Authors' conclusions: Based on currently available evidence, no confident statement can be made about the effectiveness of anticholinergics to treat people with antipsychotic-induced tardive dyskinesia. The same applies for the withdrawal of such medications. Whether the withdrawal of anticholinergics may benefit people with antipsychotic-induced TD should be evaluated in a parallel-group, placebo-controlled randomised trial, with adequate sample size and at least 6 weeks of follow-up.

Procyclidine abuse

Procyclidine hydrochloride (kemadrin) treatment of parkinsonism; result in 108 patients

Bioanalytical method for estimation of procyclidine in human plasma using liquid chromatography-tandem mass spectrometry: Application to pharmacokinetic study

A rapid, selective and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for quantification of procyclidine hydrochloride in human plasma using Procyclidine D11 hydrochloride as internal standard. Liquid-liquid extraction technique with methyl tertiary butyl ether was used for the extraction of plasma samples. Chromatographic separation of the analyte and the internal standard from the endogenous components was done on Zodiac C₁₈ column (50 × 4.6 mm, 5 ?m) using a mixture of methanol and 0.1% formic acid in water (70:30, v/v) as mobile phase at a flow rate of 1 mL/min with the run time of 2 min. The detection of the eluents was done using multiple reaction monitoring (MRM) in positive ion mode. Linearity of the method was established in the concentration range of 0.5 to 120 ng/mL. Full validation of the method was done as per USFDA guidelines and the results were well within the acceptance limits. The successful application of the method was done on healthy human subjects under fasting conditions, proving it to be used for bioequivalence and bioavailability (BA/BE) studies of procyclidine.

Stereoselectivity of procyclidine binding to muscarinic receptor subtypes M1, M2 and M4

The goals of the present study were: (1) to investigate the binding properties of (R)- and (S)-procyclidine and two achiral derivatives of muscarinic M1, M2 and M4 receptor subtypes and (2) to identify the interactions which allow these receptors to discriminate between the two stereoisomers. (R)-Procyclidine showed a higher affinity for human neuroblastoma NB-OK 1 muscarinic M1 and rat striatum muscarinic M4 receptors, as compared to rat cardiac M2 receptors. (S)-Procyclidine had a 130-fold lower affinity than (R)-procyclidine for M1 and M4 receptors, and a 40-fold lower affinity for M2 receptors. Pyrrinol, the achiral diphenyl derivative with the cyclohexyl group of (S)-procyclidine replaced by a phenyl group, has an eight-fold lower affinity for M1 and M4 receptors, as compared to (R)-procyclidine, and a three-fold lower affinity for M2 receptors. Hexahydro-procyclidine, the corresponding achiral dicyclohexyl compound, had a 10- to 20-fold lower affinity than (R)-procyclidine for the three receptors. The increase in binding free energy, which is observed when the phenyl and cyclohexyl groups of procyclidine are separately replaced by cyclohexyl and phenyl groups, respectively, was additive in the case of M1, M2 and M4 receptors. This indicates that the muscarinic receptor stereoselectivity was based on the coexistence of two binding sites, one preferring a phenyl rather than cyclohexyl group and the second preferring a cyclohexyl rather than a phenyl group. In addition, there were also binding sites for the hydroxy moiety and the protonated amino group of the ligands. The greater affinity and stereoselectivity of M1 and M4 muscarinic receptors for (R)-procyclidine reflected the better fit of the cyclohexyl group of (R)-procyclidine to the subsite of M1 and M4 as compared to M2 receptors.