Indication for the relief of nicotine withdrawal symptoms and as an aid to smoking cessation.mechanism of action nicotine is a stimulant drug that acts as an agonist at nicotinic acetylcholine receptors. these are ionotropic receptors composed up of five homomeric or heteromeric subunits. in the brain, nicotine binds to nicotinic acetylcholine receptors on dopaminergic neurons in the cortico-limbic pathways. this causes the channel to open and allow conductance of multiple cations including sodium, calcium, and potassium. this leads to depolarization, which activates voltage-gated calcium channels and allows more calcium to enter the axon terminal. calcium stimulates vesicle trafficking towards the plasma membrane and the release of dopamine into the synapse. dopamine binding to its receptors is responsible the euphoric and addictive properties of nicotine. nicotine also binds to nicotinic acetylcholine receptors on the chromaffin cells in the adrenal medulla.