title: Trial studies PI combination.
mesh_terms: D002986:Clinical Trials as Topic; D004338:Drug Combinations; D016527:Drug Costs; D004346:Drug Information Services; D017320:HIV Protease Inhibitors / Q000191:economics / Q000627:therapeutic use*; D006801:Humans; D019469:Indinavir / Q000191:economics / Q000627:therapeutic use*; D010349:Patient Compliance / Q000523:psychology; D019438:Ritonavir / Q000191:economics / Q000627:therapeutic use*
chemical_list: D004338:Drug Combinations; D017320:HIV Protease Inhibitors; D019469:Indinavir; D019438:Ritonavir