Perhaps interactions between drugs are like interactions between people: mostly inconsequential, occasionally beneficial, sometimes deadly. The principle of cancer chemotherapy before monoclonal antibodies was that the benefits of different anticancer drugs would add up, and their harmful effects would differ. This gave us CHOP and MOPP, FOLFOX, and VAMP. The principle could be extended to antihypertensive medicines (Am J Med 2009;122:290-300, doi:10.1016/j.amjmed.2008.09.038), so we may yet see HAIR (Hypovase (prazosin), Adalat (nifedipine), indapamide, and ramipril) or BALD (bendroflumethiazide, amlodipine, lisinopril, and doxazosin) replacing orthodox monotherapy. This should be good. Patients who take one drug may …