Substance use: cigarette smoking (tobacco) Flashcards
What is the structure of the mesolimbic dopamine system?
Cell bodies originate in the Ventral Tegmental area (VTA) and release dopamine into the Nucleus Accumbens (NAcc – found in the Ventral Striatum) which makes you feel rewarded.
What are the risk factors for smoking use? (x4)
- Household with current smokers or parental approval
- Low socioeconomic factors
- Mental health illness
- History of substance abuse
What are the receptor interactions of nicotine? (x2)
- Nicotine binds with neuronal nicotinic ACh receptors in the SNS and PSNS.
- Nicotine stimulates dopaminergic nerves in the Ventral Tegmental Area of the mesolimbic dopamine system by binding to nicotine ACh receptors. The increases release of dopamine and feeling of euphoria – see photo.
Why is smoking addictive? (x3)
Arises from actions of nicotine:
Speed of onset is RAPID. This has an addictive component. This is because of ‘association’ –> if you have a drug and it has immediate reward, you are more inclined to take it again.
It is quickly cleared from the system: When it is taken, it causes an euphoria, but this feeling quickly disappears. This drives further drug-seeking behaviour to restore the same effect.
Behavioural aspects: Learned associations between smoking and pleasurable activities such as meals and socialising, and with attempts to regulate mood to cope with stresses
What is the epidemiology of smoking use: Financial? Gender? Where?
Prevalence is higher in individuals below the poverty line, men, and rising in developing countries.
What are the tools used to assess smoking? (x2)
- Number of cigarettes per day
- Time to first cigarette
How is smoking use treated? (x3)
- COUNSELLING: ask, advise, assess (whether patient ready to stop), assist (those not ready to stop) and arrange follow-up (to encourage cessation long-term)
- NICOTINE REPLACEMENT THERAPY (NRT): less than 10 cigarettes/day requires gum/inhaler/spray as needed; continuous therapies such as patch for patients smoking more. If time to start first cigarette is less than 30 minutes, should consider higher doses of nicotine
- BUPROPION: antidepressant used to reduce cravings and withdrawal symptoms. Varenicline is used for the same effects too in patients who smoke more than 10 per day.
What are the complications of smoking use? (x5)
- Nicotine withdrawal symptoms
- Changes in glycaemic control in diabetes: smoking and nicotine replacement therapy increases insulin resistance (smoking more of an impact)
- Heart disease
- Cancer
- COPD
What are the symptoms of nicotine withdrawal associated with smoking cessation? (x3)
Dysphoric or depressed mood, irritability, increased appetite and weight gain.
How does nicotine impact cardiovascular health? (x2 main actions)
- Nicotine stimulates the release of catecholamines (by stimulating nicotinic ACh receptors in the SNS). This increases HR, contractility, BP, endothelial injury etc. and leads to STEMI and arrythmias.
- Nicotine also negatively impacts lipid profile; increasing levels of free fatty acids and therefore increasing levels of VLDL and LDL –> atherosclerosis –> STEMI and arrythmias.
What does nicotine do to metabolic rate?
Increases metabolic rate.
What is the impact of nicotine on neurodegenerative disorders? (x2)
Increases levels of brain CYPs (cytochrome P450 enzymes), so brain more able to metabolise toxins better. This decreases PARKINSON’S DISEASE risk.
Decreases beta-amyloid toxicity and amyloid precursor protein (APP), which decreases risk of ALZHEIMER’S DISEASE.
What is the time period for management of cigarette smoking?
Prescribed for individuals who have a stop date, and then prescribed two weeks after. Only re-prescribed if the patient has relapsed or is still trying to quit
