I agree with Skye. There's no medication that can get rid of alters, especially since there's no medication that specifically treats DID/OSDD. Sometimes when on a medication you can have more difficulty communicating with your alters because of side effects of brain fog, but that doesn't mean they're gone :) Psychiatric side effects/side effects in general also usually go away within six weeks. If you're concerned about a specific side effect of a medicine you're taking, you should talk to your doctor(s).