Trimethoprim (2.4-diamino-5-(3',4',5'-trimethoxybenzyl) pyrimidine) is a synthetic folate antagonist anti-infective agent used for the treatment of urinary tract infections and for Pneumocystis pneumonia in AIDS patients.
Bronchospasm, hypersensitivity pneumonitis.
Rash, pruritus, general urticaria, facial angioedema, fixed drug eruption.
Skin-prick tests with trimethoprim 10 mg/ ml in glycerol.
RAST TMP-HSA + RAST inhibition (TMP-HSA coupled to bis-oxirane-activated sepharose or nitrocellulose paper disks).
IgE-mediated hypersensitivity (positive cutaneous tests, specific IgE)
3 different IgE antibody binding determinants:
- 3-4 dimethoxybenzyl group.
- 2-4 diamino-5-(3',4'-dimethoxy-benzyl) pyrimidine group.
- entire TMP molecule.