Drug-induced bronchospasm: analysis of 187 spontaneously reported cases

Background: The Swiss Drug Monitoring Center (SANZ) uses a systematic approach to the collection of spontaneously reported individual cases on suspected adverse drug reactions (ADRs). Spontaneous reporting schemes are designed to detect new, rare and unexpected ADRs and to act as an early warning system but there is a tendency to overreport severe reactions.

Objectives: The aim of the study was to determine drug-induced episodes of bronchospasm, their seriousness and predisposing risk factors. An ADR is classified as serious if the reaction results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability or incapacity.

Results: From 1986 to 1995 SANZ received 8,191 case reports of suspected ADRs. In 187 cases (2%) bronchospasm was reported. In 55% of these cases the reaction was regarded as serious. Analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) were reported most frequently and were involved in 24% of the cases of which 64.5% were classified as serious. In three cases a lethal outcome was reported after intravenous administration of metamizol. Anti-infectious agents were implicated in 18% (52% serious), cardiovascular drugs in 11% (50% serious), drug formulation agents in 9% (41% serious), vaccines and immunoglobulins in 5.5% (50% serious), and plasma volume expanders in 5.5% (80% serious). Other drug groups were involved in 27% of the cases. About 50% of patients experiencing bronchospasm after NSAIDs, pharmaceutical formulation agents, vaccines and immunoglobulins had predisposing risk factors such as asthma, atopy or drug allergy. In other drug groups a predisposing factor was identified in 27% or less.

Conclusion: Drug-induced bronchospasm is frequently reported with NSAIDs, anti-infective agents, cardiovascular drugs and excipients with a high proportion of serious reactions.