Do any psychiatric drugs or their withdrawals lead to arrythmias or to the development of sleep apnea or is this neuromuscular or a different issue?

Simplify PLEASE!!: You have crammed several different questions together! some psychoactive drugs could/can prolong the qt interval & thus might contribute to an arrhythmia. Cocaine use resulting in arrhythmia is a leading cause of sudden cardiac death in young people- even athletes (len bias) some drugs suppress respiratory drive, leading to apnea, such as the dangerous combo of opiate pain drugs with tranquilizers.