It interferes with the transport of the neurotransmitter dopamine.

Which of the following alkaloids is a potent constipating agent?

Cocaine is commonly called as $:-$

Commercially, opium is obtained from which part of the plant?

Which stimulant is present in tea,cocoa,and cola drinks?

Assertion $A$: Nicotine increases blood pressure and heart rate.
Reason $R$: Nicotine stimulates the adrenal gland.
Which option is correct for Assertion $A$ and Reason $R$?