Comparing risk estimates of sulphonamide-induced agranulocytosis from the Swedish Drug Monitoring System and a case-control study

Abstract

A comparison has been made of risk estimates for agranulocytosis connected with sulphasalazine and trimethoprim-sulphamethoxazole (T-SM) therapy calculated from data in the Swedish Drug Monitoring System ("spontaneous" reports, sales and prescription information) and a population based case-control study (the IAAAS). The relative risk for agranulocytosis during sulphasalazine treatment was calculated to be 107 and 123 by the spontaneous reporting system and the case-control study, respectively. The corresponding excess risk in both systems was 1.8. For T-SM the relative risk was 17 in the spontaneous reporting system and 12 in the case-control study, while the excess risk calculated for 3 days of treatment was 0.9 in the spontaneous reporting system, and 1.6 for 3 or more days of treatment in the case-control study. It is concluded that the Swedish Drug Monitoring System gives an appropriate estimate of the risk of developing agranulocytosis in association with the two drugs studied.

Risk of acute liver injury associated with the use of drugs: a multicentre population survey

“…Additionally, the risk ratios were adjusted for the differential use of various drugs indicated for diseases concentrating on specific age groups. The case–population approach for risk estimation when the prevalence of use of the drugs of interest among those not affected is low, has been shown for a long period in pharmacovigilance studies 9, 37–39 . Fifthly, all drugs with high risk are among those described as hepatotoxic and that gives consistency to our results and sixthly, we have estimated the risks of drugs previously not related with ALI, as we took into account the frequency of exposure to drugs, independently of their known hepatotoxic potential.…”

Sulfasalazine associated agranulocytosis in Sweden 1972–1989

“…Only 19 % of the patients had taken other drugs previously associated with agranulocytosis, when their blood dyscrasia was detected. However, we believe that the reporting of agranulocytosis in connection with sulphasalazine is substantially higher, as the risk estimate is similar to that in a case-control study [12]. The relative risk of developing agranulocytosis during sulphasalazine treatment [12] is so high that other drugs should play a minor role [14,15].…”

A Swedish Regulatory Perspective on European Risk Management

“…This is interactions between warfarin and tramadol, [19] Stevens-Johnson equivalent to 280-390 reports per million inhabitants per year, and syndrome with lamotrigine, [20] drug-related blood dyscrasias, [21][22][23][24][25] is the highest reporting rate in the EU according to a recent survey Guillain-Barré syndrome associated with zimeldine, [26] myocardi-(see figure 2); [14] the annual number of reports in Sweden is shown tis and venous thromboembolism associated with clozapine, [27,28] in figure 3. The entire database now contains around 100 000 ADR lactic acidosis with biguanides, [29,30] dyspnoea, asthma and reports.…”