Coadministration has not been studied. Boosted darunavir is expected to increase risperidone plasma concentrations due to CYP3A, CYP2D6 inhibition and/or P-gp. A dose decrease may be needed for risperidone when co-administered with boosted darunavir.

Coadministration with darunavir/ritonavir may increase risperidone concentrations. A dose decrease may be needed for this drug when co-administered with darunavir/ritonavir.

Angioedema was reported in three HIV+ patients receiving risperidone with darunavir/ritonavir (n=2) or lopinavir/ritonavir (n=1). The first patient was stable on emtricitabine, tenofovir-DF, darunavir/ritonavir and developed severe swelling of the face and feet approximately 5 months after starting risperidone (2 mg twice daily). Risperidone was discontinued after which the swelling resolved completely. The second patient was stable on emtricitabine, tenofovir-DF, lopinavir/ritonavir and risperidone (0.5 mg twice daily) and developed generalized swelling of the body, more so of the face and both arms, approximately 6 months after the risperidone dose was increased to 2 mg twice daily. Risperidone was slowly decreased to 1 mg twice daily and then eventually discontinued. Swelling resolved completely after several days. The third patient was stable on emtricitabine, tenofovir-DF, darunavir/ritonavir and was started on risperidone 0.5 mg twice daily which was increased gradually to 3 mg twice daily within a year. Swelling of the face, and the arms were observed after 15 months of having been on risperidone. Risperidone was then discontinued and the swelling slowly disappeared. All three patients taking ritonavir and risperidone had no documented evidence of edema before the incident and despite different dosage regimens of risperidone, they all developed edema after several months of receiving both medications.