The effect of diclofenac (Voltarol) and pethidine on ureteric peristalsis and the isotope renogram

Diclofenac (a non-steroidal anti-inflammatory drug) and pethidine (a synthe tic opiate) are the two analgesics most commonly used to relieve the pain o f ureteric colic. Fast frame renography is a non-invasive means of imaging ureteric peristalsis and renal drainage. The aim of this study was to deter mine the effects of each of these drugs on the drainage pattern of the uppe r tracts. Twelve normal male volunteers were studied. All underwent a stand ard fast frame renogram using 75 MBq of technetium-99m-mercaptoacetyltrigly cine, and were then administered either 100 mg pethidine or 75 mg diclofena c by intramuscular injection. Fast frame renography was then repeated. Peri stalsis was determined from the condensed image of each meter and the renog ram curves were analysed to obtain standard parameters and deconvolution an alysis. Diclofenac caused a profound disruption to both ureteric peristalsi s and the renogram curve. This effect was not seen after the administration of pethidine. Deconvolution analysis suggests the effects of diclofenac ar e mediated via a direct effect on drainage rather than by any alteration of blood flow to the kidney. This study suggests that pethidine is the analge sic of choice prior to renography and that inferences about alterations of drainage in the presence of diclofenac should be interpreted with care.