CONCOMITANT USE OF ANTIHISTAMINES WITH ALCOHOL, TRICYCLIC ANTIDEPRESSANTS, BARBITURATES, OR OTHER CNS DEPRESSANTS MAY HAVE AN ADDITIVE EFFECTS. MAO INHIBITORS. KETOCONAZOLE AND ERYTHROMYCIN INCREASES THE PLASMA LEVEL AND INHIBIT THE METABOLISM. PLASMA CONCENTRATION OF LORATADINE POSSIBLY INCREASED BY AMPRENAVIR, RITONAVIR & CIMETADINE