“Many drugs such as clonidine, guanabenz, methamphetamine, imipramine, clomipramine, nortriptyline, quinine , xylazine, ephedrine, and diphenhydramine strongly inhibited the [3H]clonidine uptake with Ki values between 0.15 and 1 mM.ConclusionsClonidine is transported by a carrier-mediated process.”