Nicotine Pharmacology and the Basics of Addiction

Addiction

is a brain disease manifested by compulsive substance use despite harmful consequences

DSM-V 9 types of substance related addictions

alcohol, caffeine, cannabis, hallucinogen, inhalants, opioids, sedatives, stimulants, tobacco

Nicotine Addiction: US Surgeon General’s Report

-Cigarettes and other form of tobacco are addicting.

-Nicotine is the primary drug in tobacco that causes addiction.

The pharmacological and behavioral processes that determine tobacco addiction are similar to those that determine addiction to drugs such as heroin and cocaine

How long does it take for nicotine to reach the brain after inhalation

10-20 seconds

Nicotine mimics

acetylcholine receptors

Nicotine and the body

trouble breathing, damage to lungs, heart beats faster, activates fight or flight response, increase acid reflux

Nicotine pharmacodynamics on the CNS

pleasure, enhanced vigilance, arousal, improved task performance, anxiety relief

Nicotine Pharmacodynamics Other

appetite suppression, increased metabolic rate, skeletal muscle relaxation

Nicotine Pharmacodynamics Cardiovascular System

increased heart rate, increased cardiac output, increased blood pressure, coronary vasoconstriction, cutaneous vasoconstriction

Dopamine

pleasure, appetite suppression

Norepinephrine

arousal, appetite suppression

Acetylcholine

arousal, cognitive enhancement

Glutamate

learning, memory enhancement

Serotonin

Mood modulation, appetite suppression

B-Endorphin

reduction of anxiety and tension

GABA

reduction of anxiety and tension

Nicotine Pharmacology

Colorless, weak base

pka 8.0

In acidic media nicotine is

ionized which means it is poorly absorbed across membranes

Nicotine in alkaline media

nonionized= well absorbed across membranes

Nicotine absorption Buccal

-pH inside the mouth is 7.0

-acidic media (cigarette): decrease absorption

-alkaline media: increase absorption

Lung nicotine absorption

-pH of the lung is 7.4

-Large alveolar surface area

-Extensive capillary system in lung

What is the by product of nicotine metabolism?

cotitine

Half life of nicotine

2 hours

Cotinine half life

16 hours

Nicotine excretion

-occurs through kidneys (pH dependent; increase with acidic pH)

-through breast milk