Ranitidine and theophylline.
D000368:Aged; D004347:Drug Interactions; D006801:Humans; D008297:Male; D011899:Ranitidine / Q000009:adverse effects*; D013806:Theophylline / Q000097:blood / Q000506:poisoning*
D011899:Ranitidine; D013806:Theophylline