protease-sparing regimen protease-sparing regimen protease-sparing regimen, often abbreviated as psr, is a method or therapy for treating people infected with hiv that involves a three-drug combination that reduces viral load below the limit of detection while saving protease inhibitors for later use. it is considered a weaker (in terms of quantity and concentration) form of hiv treatment. it has been argued that such a regimen is not as potent as giving hiv patients with the strongest drugs as soon as it is detected. others believe that this might be considered a long-term strategy in order to reduce the amount of hiv, and in some instances have proven to be successful. protease-sparing regimenother namespsrspecialtyvirology