Rivastigmine is a carbamate derivative of physostigmine that inhibits both acetyl choline esterase and butyl choline esterase. Exelon is more selective for G1 form of acetyl choline esterase. Acetyl choline esterase predominates in certain areas of brain. Rivastigmine Tartrateis highly lipid soluble and can easily enter brain. Rivastigmine Tartrateaugments cholinergic transmission in brain with mild peripheral effect. The carbamyl residue of Rivastigmine Tartrateinhibits Acetyl choline esterase for up to 10hrs. You can now easily buy Rivastigmine here Rx 2 Go Pharmacy.