Life-Threatening Reaction to Lifesaving Medication: Stepwise Approach to Severe Adverse Reactions to PCSK-9 Monoclonal Antibodies.

Typical side effects of proprotein convertase subtilisin/kexin type 9 monoclonal antibodies including influenza-like illness and injection site reactions, are minor and well tolerated. This case, however, highlights a less common but severe reaction, indicating the need for clinicians to understand and manage potential rare side effects noted with biologics.