Setting

This audit has relevance across all settings where antimuscarinic medications are prescribed (e.g. acute in-patient, rehabilitation and community settings).

Background

Antimuscarinic drugs are extensively used in mental health settings. However, clinical research and guidance on their use are scant. Their longer-term sideeffects include autonomic effects, cognitive impairment, agitation and the initiation or worsening of tardive dyskinesia (Birmingham et al, 1999). Hence, clinicians need regularly to monitor the use of these medications (World Health Organization, 1990).

Standards

Standards were developed from several evidence-based sources (Birmingham et al, 1999; Steele, 2000; Taylor et al, 2007; Joint Formulary Committee, 2009):

ᐅ Only one antimuscarinic should be prescribed for each patient.

ᐅ Doses of antimuscarinics should not exceed the limits set out in the British National Formulary (BNF) (Joint Formulary Committee, 2009).

ᐅ Continued use of antimuscarinics should be reviewed at least every 3 months.

ᐅ If on antimuscarinics for more than 3 months, dose reduction should be attempted in the absence of extra-pyramidal side-effects.

ᐅ Antimuscarinic use on an ‘as required’ (p.r.n. basis) should be reviewed at least once every 4 weeks.

ᐅ Antimuscarinic drug prescriptions should be removed from the p.r.n. chart if the drug has not been administered in the previous 2 months.

The target is that these standards are met for all patients who are prescribed antimuscarinic medication.

Method

Data collection

Current prescription data (either drug cards or last clinic letter) and the medical notes on antimuscarinic medication were examined for each patient in the relevant service of interest. Patients who were currently prescribed antimuscarinics were included in the audit, with a view to obtaining the following information:

ᐅ the number of in-patients on antimuscarinic medication and their diagnoses

ᐅ details of antipsychotic medications, including names, whether typical or atypical and number

ᐅ frequency of antimuscarinic use, their number, names, whether their total dose exceeded BNFlimits and duration of use

ᐅ whether dose reduction or withdrawal had been considered or attempted where appropriate, for patients on antimuscarinics for more than 3 or 2 months, respectively

ᐅ whether prescribed p.r.n. antimuscarinic medication had been reviewed within the preceding month

ᐅ total time on the current dose of antimuscarinic medication.