There are medication substitutes that can be given to reduce withdrawal symptoms as part of drug or alcohol related cessation programmes. On the whole don’t even need people in a coma (which implies so unconscious they need tubes to support breathing and other risky associated treatments). In very bad withdrawals such as seizures happening, the benzodiazapene levels used to control the withdrawal can definitely cause drowsiness bit rarely bad enough to need breathing support.
The reason they’re given as part of a programme is that quitting is only partially about physical addiction, psychological addiction (cooling mechanism alternatives and social triggers etc) need to be addressed.
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