CYSTITIS AND NONSTERIODAL ANTIINFLAMMATORY DRUGS - AN INCIDENTAL ASSOCIATION OR AN ADVERSE EFFECT

Aims. Cystits, a rare adverse effect of systematically administered dr ugs, was first reported to be associated with a nonsteroidal antiinfla mmatory drug, tiaprofenic acid, in 1991. Similar reports of adverse ef fect of tiaprofenic acid were received by a number of national drug mo nitoring centres. It was therefore deceided to investigate the frequen cy of cystitis associated with tiaprofenic acid and to see whether thi s association is typical of tiaprofenic acid or also occurs with other nonsteroidal antiinflammatory drugs. Methods. The Medicines Adverse R eaction Monitoring Centre has been monitoring drug related events/reac tions since 1965. An analysis of the spontaneous adverse reaction repo rts received at this centre during the period 1965-92 was carried out. Results. Haemorrhagic cystitis was reported to be associated with tia profenic acid (n=3) and indomethacion (n=3). In addition 11 other repo rts of haematuria (not associated with any coagulopathy and/or hepatic disorders) in relation to other nonsteroidal antiinflammatory drugs, such as diclofenac, ketoprofen, naproxen and piroxicam were received. Five patients who were rechallenged with the suspect drug, suffered fr om recurrence of cystitis/ haematuria. Conclusions. In addition to tia profenic acid, cystitis appears to be associated with indomethacin and possibly also with other nonsteroidal antiinflammatory drugs. An alle rgic or immunological mechanism is probably responsible for this react ion. Although our centre received the first report of cystitis in rela tion to indomethacin in 1966, judging by the number of reports receive d, this association appears to be poorly recognised.