Publications by authors named "Richard Alfred Preston"

The pharmacokinetics (PK) and safety of single-dose alpelisib (300 mg) were assessed in participants with moderate to severe hepatic impairment (n = 6 each) compared with their matching healthy controls (n = 11). Blood samples were collected upto 144 hours post-dose and evaluated by liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay. The primary PK parameters (maximum plasma concentration [C], area under the curve [AUC] and AUC) and secondary PK parameters (AUC, apparent total body clearance [CL/F], apparent volume of distribution [Vz/F], time of maximum observed concentration [T], and half-life [T]) of oral alpelisib 300 mg were determined from individual plasma concentration-time profiles using non‑compartmental analysis.

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Nirmatrelvir coadministered with ritonavir is highly efficacious in reducing the risk of coronavirus disease 2019 (COVID-19) adverse outcomes among patients at increased risk of progression to severe disease, including patients with chronic kidney disease. Because nirmatrelvir is eliminated by the kidneys when given with ritonavir, this phase I study evaluated the effects of renal impairment on pharmacokinetics, safety, and tolerability of nirmatrelvir/ritonavir. Participants with normal renal function (n = 10) or mild, moderate, or severe renal impairment (n = 8 each) were administered a single 100-mg nirmatrelvir dose with 100 mg ritonavir given 12 hours before, together with and 12 and 24 hours after the nirmatrelvir dose.

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