Lesson of the Week: Allopurinol, erythema multiforme, and renal insufficiencyBMJ 1996; 312 doi: https://doi.org/10.1136/bmj.312.7024.173 (Published 20 January 1996) Cite this as: BMJ 1996;312:173
- A Kumar, lecturera,
- N Edward, consultant nephrologista,
- M I White, consultant dermatologista,
- P W Johnston, honorary senior registrarb,
- G R D Catto, professora
- a Department of Medicine and Therapeutics, University of Aberdeen Medical School, Foresterhill, Aberdeen AB9 2ZD
- b Department of Pathology, Aberdeen Medical School
- Correspondence to: Dr Kumar.
- Accepted 5 October 1995
Allopurinol, a xanthine oxidase inhibitor, has become established as the drug of choice for preventing and treating conditions where there is overproduction of uric acid, such as occurs in gout, uric acid nephrolithiasis, and polycythaemia vera; during chemotherapy for lymphomas; and in the Lesch-Nyhan syndrome.1 Allopurinol may, however, cause a severe, and sometimes fatal, hypersensitivity reaction in patients with pre-existing renal disease. We describe two patients with severe hypersensitivity. In both the syndrome was relapsing and in one ultimately fatal.
Allopurinol should be prescribed judiciously in the presence of renal insufficiency, in reduced dosage, but where possible is best avoided
A 52 year old man presented with a five day history of a widespread rash, oral and genital ulceration, fever, malaise, diarrhoea, and diminished urine output. Five weeks earlier he had developed gout in his great toe, for which he was treated with ibuprofen followed by allopurinol 300 mg daily. Then his serum urate concentration was 0.78 mmol/l (normal <0.42) and serum creatinine concentration 130 μmol/l (normal <110). Idiopathic dilated cardiomyopathy had been diagnosed three years previously. He had taken warfarin, enalapril, and frusemide regularly since then and, intermittently, ibuprofen for episodic back pain.
On examination he was feverish and unwell. His face was red and oedematous, and he had blistering on his hands and feet, superficial ulceration in the mouth and conjunctiva, and balanitis. He had a morbilliform rash over his trunk and limbs (fig 1). Blood pressure was 80/50 mm Hg and urine output 20 ml/h. There was haematoproteinuria but no urinary casts. The white cell count was 17 × 109/l with 70% neutrophils and 12% eosinophils. Erythrocyte sedimentation rate was 85 mm in 1 h, alanine aminotransferase concentration was 143 U/l (normal <31), and the creatinine concentration had risen to 360 μmol/l. The kidneys …