If you use methamphetamines for narcolepsy with prescription while on probation will you go to jail?

I'm not aware of methamphetamines being prescribed, however, amphetamines are often prescribed by your doctor for narcolepsy. Just make sure you report to probation, and if asked about medications, that you disclose all prescriptions, and be prepared to show documentation of the prescription. They cannot revoke your probation for taking something medically necessary.