Prevalence of drugs with constipation-inducing potential and laxatives in community-dwelling older adults in Bahrain: therapeutic implications

Abstract

Objectives: This study evaluated the prevalence of prescribing drugs with constipation-inducing potential and the prophylactic use of laxatives in community-dwelling older adults. Method: An audit of outpatient prescriptions ordered for older adults aged ≥65 years with one or more chronic morbidities in 24 governmental primary healthcare centres in Bahrain. The prescriptions were collected by pharmacist-in-charge of each health centre between December 2015 and June 2016. The proportion of prescriptions with constipation-inducing drugs and co-prescribed laxatives was determined. Key findings: The overall prevalence of prescribing drugs with the potential to cause constipation was 30.5% (642/2106). Prescriptions with at least one anticholinergic/drug with anticholinergic potential (DAP) were 22.5% (473/2106): single medication in 16.6% (350/2106) and two or more combinations in 5.9% (124/2106). A combination of two or more anticholinergics/DAP accounted for 2.9% (61/2106) prescriptions. Constipation-inducing drugs other than anticholinergics such as multivalent cation preparations and non-dihydropyridine calcium channel blockers were prescribed in 8.0% (168/2106) of cases. Orphenadrine and first-generation antihistamines, both with high anticholinergic drug burden, were the frequently prescribed medications, either alone or combined. The rate of prescribed laxatives was 2.96% (19/642), mostly for those on constipation-inducing drug monotherapy. Conclusion: Approximately a third of prescriptions for older adults had constipation-inducing medications, typically a single DAP. Prescribing laxatives were uncommon and did not correlate with the prevalence of prescribing drugs with constipation potential. Physicians' awareness about anticholinergic drugs and their potential risks, and the prophylactic use of laxatives to mitigate iatrogenic constipation are to be included in continuing professional programmes.