1. Myasthenia gravis
is an autoimmune neuromuscular disease
leading to fluctuating muscle weakness
and fatigue and since the disease is diagnosed and already medicine prescribed, thus he is under medical Supervision.
2. Methadone is a synthetic opioid,[ that work by mimicking the action of naturally occurring pain-reducing chemicals called endorphins.] very similar to morphine and has been used primarily as substitution therapy of opioid dependence.[Methadone is an opioid that is used mainly to wean people off their addiction to stronger opioid such as heroin,methadone prevents the physical withdrawal symptoms
that occur when these drugs are stopped.This prevents physical cravings for the drug.
3. Adderall [amphetamine,dextroamphetamine]: ) is used to treat narcolepsy and attention deficit hyperactivity disorder
(ADHD), and may cause the following symptoms that are related to myasthenia gravis [MG]
i. Muscle weakness in 6% of people.
ii. Stroke caused by blockage of the arteries that supply blood to the brain.
So instead of going for maximum limit, [for which he is insisting] have your Doctor review the same.