Grapefruit juice increases the bioavailability of artemether

Six healthy men took 100 mg artemether with water, then a week later with 350 ml grapefruit juice. Grapefruit juice more than doubled Cmax (42 → 107 ng/mL) and nearly doubled AUC (177 → 336 ng·h/mL), while shortening tmax (3.6 → 2.1 h) and leaving half-life unchanged. Saliva showed negligible drug levels, and no ECG changes (bradycardia or QTc prolongation) were detected. The authors conclude grapefruit juice inhibits intestinal CYP3A4, reducing first-pass metabolism and boosting oral bioavailability of artemether.

Source : https://pubmed.ncbi.nlm.nih.gov/10456492/