Before starting antiplatelet therapy, what is a critical factor to assess in patients?

Assessing a patient's allergy history is crucial before initiating antiplatelet therapy because certain medications in this class can provoke allergic reactions in susceptible individuals. For instance, patients may have a documented allergy to specific antiplatelet agents like aspirin or clopidogrel, which could lead to serious adverse effects such as anaphylaxis or urticaria. Understanding a patient's allergy history helps in selecting an appropriate antiplatelet agent that will be effective while minimizing the risk of an allergic response.

Other factors, such as patient age, renal function, and smoking status, while relevant in the overall assessment of a patient's treatment plan, do not carry the same immediate risk associated with direct allergic reactions. Adjustments related to age or renal function typically pertain to dosing and the tolerability of the medication rather than the fundamental ability to safely begin therapy. Smoking status may influence cardiovascular risk and treatment decisions, but it does not pose a direct threat as an allergy would.