Drug Allergies

Drug Allergies

Should all NSAIDS be avoided in patients with aspirin reactions?

Most aspirin and NSAID reactions AREN’T immune mediated or TRUE allergies.  Most are sensitivities due to inhibition of COX-1 which triggers leukotriene productions…leading to bronchospasm, hives, etc.

Patients with aspirin sensitivity are usually also sensitive to NONselective NSAIDS such as ibuprofen, naproxen, ketorolac, etc.  Avoid nonselective NSAIDS in these patients.Consider these alternatives for patients with aspirin sensitivity.

Acetaminophen or salsalate weakly inhibit COX-1 but cross-sensitivity with aspirin usually isn’t  a problem at lower dose.  Try up to 650mg/dose of acetaminophen   and 1500mg/dose of salsalate for people with aspirin sensitivity.

Celecoxib (Celebrex) prescribing info discourages using it in patients with aspirin sensitivity.  But cross – sensitivity is rare..because it’s COX-2  selective.

Meloxicam (Mobic,etc) is COX-2 selective at low doses but loses selectivity at high doses.  Try up to 7.5 mg/day for meloxicam.

Consider giving the first dose of these alternatives in your office in case there’s a reaction or refer patients to an allergist.

Occasionally a reaction to aspirin is immune mediated.  In this case, it’s usually okay to use an NSAID because its chemical structure is different than aspirin.

The problem is that it’s hard to distinguish between aspirin sensitivity and a true allergy.  When in doubt, refer these patients to an allergist for evaluation.

Curr Allergy Asthma Rep 2009;9:155