Understanding and improving the use of allopurinol in a teaching hospital

BACKGROUND

An emphasis on renal function in deciding maintenance doses of allopurinol to prevent allopurinol hypersensitivity has resulted in ineffective prevention of attacks of gout. New therapeutic guidelines for gout have shifted the focus back to titrating maintenance doses to reach a serum uric acid (SUA) concentration target of ≤ 0.36 mmol/L.

AIMS

To examine trends in the prescribing of allopurinol in a teaching hospital and their concordance with the new guidelines for gout management, and to explore prescribers' approaches and attitudes to the use of allopurinol.

METHODS

An audit was conducted of all inpatients prescribed allopurinol at a teaching hospital between January 2008 and December 2012. Allopurinol dose, SUA, serum creatinine concentrations and estimated glomerular filtration rates were extracted from the hospital databases. Doctors from medical units who regularly prescribed allopurinol were interviewed.

RESULTS

The allopurinol dose prescribed in gout patients most commonly was a continuation of the pre-admission dosage. Dosage change during admission was rarely observed. Dosages reflected a consideration of renal function. SUA concentrations were measured in only 21% (n = 269) of gout patients. Prescriber interviews (n = 12) reflected adequate knowledge regarding allopurinol use, but most maintained that the primary care setting was more suitable for the management of dose titration in gout.

CONCLUSIONS

SUA concentrations were not routinely measured in the majority of admitted gout patients taking allopurinol. Without SUA measurements and allopurinol dose titration, patients with SUA > 0.36 mmol/L are at increased risk for acute attacks of gout in hospital.