Levodropropizine-Induced Anaphylaxis: Case Series and Literature Review.

Levodropropizine is commonly used as an antitussive drug for acute and chronic cough. It is a non-opioid agent with peripheral antitussive action via the modulation of sensory neuropeptide levels in the airways. Thus, levodropropizine has a more tolerable profile than opioid antitussives. However, we experienced 3 cases of levodropropizine-induced anaphylaxis. Three patients commonly presented with generalized urticaria, dyspnea, and collapse after taking cold medication including levodropropizine. To find out the culprit drug, we performed skin tests, oral provocation tests (OPTs), and basophil activation tests (BATs). Two patients were confirmed as having levodropropizine-induced anaphylaxis by OPTs, and one of them showed positive to skin prick tests (SPTs). The other patient was confirmed by skin tests and BATs. When we analyzed pharmacovigilance data related to levodropropizine collected for 5 years, most cases (78.9%) had allergic reactions, such as rash, urticaria, angioedema, and anaphylaxis. Therefore, physicians should consider that levodropropizine can be a culprit drug, when anaphylaxis occurs after taking anti-cough or common cold medication.