Yes, we are very fortunate to have other choices now. I took Mestinon for quite a few years and then was switched to prostigmin when GI problems began. I will have to tweak my dosage of Mestinon and hopefully get it right within a short time. My son is getting married next week so I will not risk that until after the wedding! The two drugs are different and as far as I know, there is no problem getting Mestinon or generic form.