In total, ten potentially dangerous prescriptions were found for interaction (4.8%): digoxin in patients with renal failure at a dosage > 0.125 mg (2 cases, 0.9%); three cases with risk of “triple whammy” (NSAIDs + ACE inhibitor/angiotensin-2 antagonists + furosemide) (1.4%), one case with risk of serotonin syndrome (SSRI + tricyclic + selegilin), three cases of pharmacodynamic antagonism (donepezil-biperiden, antidiarrheal/laxative, risperidone/L-DOPA), and one case of pharmacodynamic synergy (two sedative-hypnotic administered improperly together). The gene discussed is AGT; the disease is serotonin syndrome.