IT MAY ENHANCE THE SEDATIVE EFFECTS OF CNS DEPRESSANTS INCLUDING ALCOHOL, BARTIBURATES, HYPNOTICS, OPIOID ANALGESICS, ANXIOLYTIC SEDATIVES, AND ANTIPSYCHOTICS. CONCOMITANT ADMINISTRATION OF ERYTHROMYCIN OR KETOCONAZOLE THE PLASMA CONCENTRATIONS OF MEPYRAMINE HAVE BEEN INCREASED. ANTACIDS CONTAINING ALUMINIUM, MAGNESIUM REDUCED THE ABSORPTION OF MEPYRAMINE.