Why do dopamine agonists cause sleepiness?

Question by Sergej Varslavan: Why do dopamine agonists cause sleepiness?
All the meds that are dopamine agonists have a comon side effect – sleepiness. But i dont understand. Amphetamine, ritalin, meth and cocaine raise dopamine levels in the brain and make you alert, wired and active, but dopamine agonists which do the same thing as dopamine does make you sleepy. Why?

Best answer:

Answer by Sandra
Dopamine isn’t responsible for being alert and active, it’s responsible for pleasure (you’re not all wired and active after taking a shot of heroin, it’s a depressant and those that you said are stimulants). If you’re taking pills to get off drugs, it’s the hardest to fall asleep during withdrawal and that’s why they get mixed with other substances or them themselves have an effect to help you finally fall asleep. Has nothing to do with dopamine.
Hope it helped.

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