Liquorice reduced cyclosporine bioavailability by activating P-glycoprotein and CYP 3A

► Liquorice activated P-gp and CYP3A4. ► Liquorice significantly decreased the oral bioavailability of cyclosporine. ► Liquorice is contraindicated for patients treated with cyclosporine. ► Concurrent use of liquorice with substrates of P-gp and CYP3A4 should be exercised with caution.