Milk thistle (silymarin) and darunavir/ritonavir
The effect of the botanical supplement milk thistle (silymarin, 150 mg every 8 hours) on the pharmacokinetics of darunavir/ritonavir (600/100 mg twice daily) was investigated in 15 HIV positive patients.
In the presence of milk thistle, Darunavir AUC, Cmax and Ctrough decreased by 14% (GMR 0.86: 90%CI 0.67-1.10), 17% (GMR 0.83; 90%CI 0.68-1.02) and 6% (GMR 0.94; 90% CI 0.70-1.26), respectively.
As all patients had darunavir concentrations well above the median protein-binding-adjusted IC50, the study concluded that no dose adjustment for darunavir/r appears to be necessary.
Molto J et al. Effect of milk thistle on the pharmacokinetics of darunavir/ritonavir in HIV-infected patients. 13th PK Workshop, 16-18 April 2012, Barcelona. Abstract: P_04.