A longitudinal study of serum creatinine levels in patients of rheumatoid arthritis on long term NSAID therapy.

ABSTRACT

AIM: Primary To study the effect of long term NSAID therapy on serum creatinine in patients of rheumatoid arthritis. Secondary To study the effect of discontinuation, reduction in the dose or continuation of NSAID and of rechallenge. MATERIAL AND METHODS: Case records of RA patients with a minimum two years of follow up were analysed. Age, sex, duration of RA, type, dose and duration of NSAID and DMARD therapy, co-morbid conditions and serial serum creatinine levels were charted. RESULTS: Ninety nine case records were studied. Incidence of abnormal creatinine level (renal insufficiency) defined as rise in creatinine equal to or above the upper limit of normal was 27.7%. This rise was asymptomatic in all patients. No NSAID was particularly associated with an increased risk in renal insufficiency. The rise of serum creatinine was reversible in most patients irrespective of discontinuation or continuation of NSAID but settled at a higher level. Rechallenge resulted in rise of serum creatinine in 50% patients. Hypertension, DM, IHD and diuretics carried a higher but not statistically significant risk of renal insufficiency. CONCLUSION: NSAID-induced asymptomatic rise of creatinine in patients of RA on long term NSAIDs is common. It is mostly reversible. Regular monitoring of serum creatinine is essential.