Icatibant: Uses, Mechanism, and Side Effects

Sudden swelling attacks from hereditary angioedema can be frightening and unpredictable, and patients often want to know what treatment options exist for acute episodes. Icatibant is one such option, approved specifically to address attacks as they occur.

Key takeaways

• Icatibant is a bradykinin B2 receptor antagonist approved to treat acute hereditary angioedema (HAE) attacks in adults 18 and older.
• It is marketed under the brand name SAJAZIR and carries no boxed warning.
• More than 40 clinical trials have studied icatibant or related bradykinin-pathway approaches for angioedema.
• FDA Adverse Event Reporting System data most frequently lists hereditary angioedema itself and drug-ineffectiveness reports alongside injection site pain.
• Reported weight changes and product use issues appear often in adverse event reports, though these reflect reporting patterns, not confirmed side effects.

What Icatibant Is

Icatibant works by blocking the bradykinin B2 receptor, competing with bradykinin at that site with similar binding affinity. In hereditary angioedema, a missing or malfunctioning protein called C1-esterase-inhibitor allows a cascade of proteolytic activity that generates excess bradykinin. Because bradykinin widens blood vessels and drives the swelling, inflammation, and pain typical of HAE attacks, blocking its receptor is the therapeutic strategy behind icatibant.

What Icatibant Is Approved For

Icatibant, sold as SAJAZIR, is approved for treating acute attacks of hereditary angioedema in adults aged 18 and older. It is classified as a bradykinin B2 receptor antagonist. The current label does not carry a boxed warning.

What the Evidence Shows

Icatibant and related bradykinin-pathway compounds have been the subject of more than 40 registered clinical trials. Among sampled studies, a completed Phase 2 trial evaluated BCX7353 for preventing angioedema attacks in people with hereditary angioedema. A separate Phase 1 trial examined a bradykinin receptor blocker for ACE inhibitor-associated angioedema, though that study was terminated.

Reported Side Effects

Adverse event reports submitted to FDA most commonly reference hereditary angioedema itself, the underlying condition being treated, along with reports describing the drug as ineffective. Injection site pain is also frequently reported, consistent with icatibant's injectable route. Weight decreased and weight increased both appear as common report terms, alongside product use issues and instances of off-label use. These figures represent counts of submitted reports, not confirmed rates of occurrence or evidence of a causal link to icatibant.