Nicotine addiction and treatment Flashcards
What characterises tobacco dependence?
It is a chronic, relapsing condition, sustained by nicotine
What are the three types of treatment for tobacco dependence?
- Medication
- Behavioural support
- Electronic cigarettes
What is the smoking prevalence?
> 1 billion people smoke cigarettes
> Smoking rates have declined in UK, USA, Australia and New Zealand to less than 20%
> Some groups have not benefitted from tobacco control initiatives
What is the smoking prevalence in people with Depression and anxiety?
32%
What is the smoking prevalence in people with psychosis?
62%
What is the smoking prevalence among substance users?
80%
When does tobacco dependence usually start?
Usually in childhood
What happens physiologically when you smoke?
> Nicotine rapidly absorbed through lungs
> Stimulates nicotine acetylcholine receptors in VTA
> Iincreased firing and release of dopamine in VTA -> increased amount in nucleus accumbens
= Direct Reward pathway
-> “teaching signal” to get more
What are the rewarding properties of nicotine?
> Stimulant which improves attention and mood
> BUT tolerance diminishes these cognitive improvements
What is the mechanism of nicotine tolerance?
Negatively reinforcing:
- brain adapts and has to be cooped up in order not to experience irritability and loss of concentration
What is the half-life of nicotine and what is its consequence?
Nicotine half-life = 2 hours
-> after short periods of not smoking -> experience of withdrawal symptoms
=> brain teaches smoker to smoke in presence of withdrawal symptoms
How are cigarettes engineered to get nicotine to the brain?
Ammonia + Cocoa:
- products and chemicals added to tobacco plant as it’s growing or after harvest
- some chemicals are dangerous and become more toxic once tobacco is burned
What is the action of ammonia in cigarettes?
Speeds up transport of nicotine form lungs to brain
best used for cleaning toilets
What is the action of cocoa in cigarettes?
- Enhances taste
AND - It’s a bronchodilator: widens airways
-> more tobacco smoke in your lungs -> more nicotine to brain (reward pathway…)
What composes tobacco smoke?
> Ammonia
> Cocoa
> 500 gases: carbon monoxide, ammonia, formaldehyde, hydrogen cyanide
> 3,500 particulates: nicotine, tobacco nitrosamines, polycyclic hydrocarbons
How does nicotine differ from other ingredients of tobacco smoke?
> Nicotine: main cause of addiction and dependence
> Other ingredients (toxins, carcinogens): main cause of high mortality rate
Why does the nicotine delivery system matter?
Because nicotine is the main cause of addiction and dependence (not mortality)
-> switching to a less harmful form of nicotine delivery system is a step away from tobacco smoking
AND a step towards better health
What is the average duration of most withdrawal symptoms?
- Top-up needed every 2 hours
- Peak 24-48 hours after quitting
- Subside within 2-4 weeks
What does the plasma nicotine concentration graph of Benowitz (2010) tell us?
First cigarettes of the day are the most pleasurable and satisfying
- in neutral zone: no pleasure/arousal and no withdrawal (abstinence) symptoms
What are the physical health damages of smoking?
> Harms heart and affects blood circulation
> Harms brain and can cause strokes
> Lung related illnesses
- bronchitis, emphysema, cancer, chronic obstruction pulmonary disease
> Reproductive health damages
> Dental damages
> Bone damages
=> 50% of smokers will die of smoking related disease
What characterises chronic obstruction pulmonary disease?
Progressive and debilitating condition
How does smoking contribute to poor mental health?
> More severe symptoms of psychosis
> Higher rates of depression, anxiety
-> longer time in hospital
> Higher doses of medication needed
> Can cause poverty
> Exploitation and stigma
> Unhealthy coping skills (reach cigarette at times of stress)
How does smoking lead to a need of higher doses of medication?
Tar in tobacco smoke speeds up metabolism of some medication
-> lower levels of drug in the blood
How can smoking lead to poverty in people with mental health conditions?
A lot of people with mental health conditions spend approximately 1/3 of their income on cigarettes per week
What is the current treatment pathway for tobacco dependence?
- Health professionals raise issue of smoking
- at every appropriate moment - Advise smokers to quit
- Offer support
- If person receptive: referral to trained practitioner
- Trained practitioner provides combination of medication and behavioural support
What is the available medication for treating tobacco dependence?
> Nicotine replacement therapy (NRT) products
> Bupropion
> Varenicline
> Nortriptyline
> Cytisine
What is the importance of medication for treating tobacco dependence?
At least doubles smoker’s chances of quitting
What are the types of behavioural support for treating tobacco dependence?
- One to one
- Group
- Telephone
- Self-help materials
=> improves smoker’s chances of quitting
What characterises nicotine replacement therapy (NRT) products?
> 8 NRT products on the market
> More effective when 2 types used together
> All products are equally effective -> smoker’s choice
> Use of these products requires explaining and practice
What are the currently available nicotine replacement therapy (NRT) products?
> Nicotine patches
> Lozenges and chewing gum
> Inhalator
> Nasal and mouth sprays
> Tablets
> Mouth strips
What are the properties of nicotine patches?
- Deliver regular dose of nicotine over 16 or 24 hours
- Long-lasting action
- > they can be worn around the clock
What are the properties of lozenges and chewing gum (NRT)?
- Release nicotine as they are absorbed through cheeks
- Start with 1/hour
- Use up to 15 pieces a day
What are the properties of inhalators for nicotine replacement therapy (NRT)?
- Can help if you miss physical action of smoking
- You can have up to 6 cartridges per day
What are the properties of nasal and mouth sprays?
- Deliver nicotine quicker than other NRT products
- Have up to 64 sprays per day
1-2 sprays/hour
What are the properties of tablets for nicotine replacement therapy (NRT)?
- Dissolve under your tongue
- > more discreet than lozenges
- Normally start with 1-2 tablets per hour
- Up to 40 per day
What are the properties of mouth sprays for nicotine replacement therapy (NRT)?
- Dissolve on top of the tongue
- Have up to 15 per day
How to manage the dosage of smoker’s medications?
> Smokers often under dose on medications
- > they are encouraged to constantly keep up on their levels of nicotine rather than react to a craving
- > assess level of withdrawal discomfort and adjust dose
> Professional support is vital to successfully quitting
What is the average time for oral NRT products to take effect?
15-20 minutes
What is the average time for mouth and nasal NRT products to take effect?
5 minutes
What characterises the medication Bupropion (Zyban)?
- Antidepressant
- Acts on dopamine and noradrenaline pathways
- Used for at least 8 to 12 weeks
What characterises the medication Varenicline (Champix)?
> Nicotine acetylcholine partial agonist
- targets α4β2 receptor subtype
> Designed to reduce motivation to smoke
- makes cigarettes less satisfying
- reduces cravings, withdrawal symptoms, and reward from smoking
> Used for 12 weeks (with option of further 12 weeks)
What are the potential neuropsychiatric side effects of varenicline, bupropion and nicotine patches for smokers with and without psychiatric disorders (Anthenelli et al., 2016)?
- Anxiety
- Depression
- Agression
- Delusions
- Hallucinations
- Psychosis
- Suicidal behaviour
What is the efficacy (quit rates) of varenicline, bupropion and nicotine patches in smokers with and without psychiatric disorders (Anthenelli et al., 2016)?
Efficacy of medications in terms of odds ratios is similar for smokers with or without psychiatric disorders
Do varenicline or bupropion have varying neuropsychiatric adverse events relative to nicotine patches or placebo?
No significant increase in rates of neuropsychiatric adverse events in Varenicline or Bupropion relative to nicotine patch or placebo
What are the implications of the absence of significant difference in rates of neuropsychiatric adverse events between Varenicline or Bupropion and nicotine patches or placebo?
- Good news for smokers with mental illnesses
- Hope of change in prescribing behaviours of many doctors who’ve been put off by early case negative reports
(e. g. varenicline may compromise individual mental health)
What are the common side effects of nicotine replacement therapy (NRT) products?
- Skin rash
- Hiccups
- Sore throat
- Sleep disturbance
What are the common side effects of Varenicline?
- Sleep disturbance
- Dry mouth
- Nausea
- Dizziness
What are the common side effects of Bupropion (Zyban)?
- Sleep disturbance
- Nausea
- Change in taste
- Dry mouth
What is the consequence of overlapping side effects between NRT products, Varenicline and Bupropion?
It can be difficult to know whether patient’s sleep disturbance is due to withdrawal or because of NRT, Varenicline or Bupropion taken
What are the 3 elements that constitute a structured programme of behavioural support?
- Education on how dependence develops and is sustained
- Minimise withdrawal symptoms through medication
- Personal coping plans
- get ahead of potential cravings that might occur
What is the structure of the standard treatment programme of behavioural support for smoking, which is available online?
> Session 1: Pre-quit Assessment
> Session 2: Quit Date
> Session 3: 1, 2, 3 weeks post Quit Date
> Session 4: 4 weeks post Quit Date
(4-week follow-up appointment)
What can people who don’t want to quit smoking do?
Switch to cleaner forms of nicotine
- e-cigarettes: less harmful nicotine delivery system
- 2.6 million e-cigarette smokers in UK
What characterises E-cigarettes?
> Not a licensed medication
> E-cig use led by smokers, rather than public health and tobacco communities
> Media debate if they are safe
> Rapidly evolving technology
> Battery, heating element/coil, e-liquid
What does an e-liquid typically contain?
- Nicotine
- Propylene glycol or glycerin
- Flavours
What are the differences between cigarettes and e-cigarettes?
- No tobacco in e-cigarettes
- Solution is heated not burned
- E-cigarettes are vaped, not smoked
What is the effectiveness of e-cigarettes?
Likely comparable to other evidence-based treatments (e.g. NRT, Bupropion, Varenicline) when taking into account other factors such as self-selection
What are the common side effects of e-cigarettes?
- Dry throat and cough
- BUT normally disappears
Why should smokers switch to vaping completely?
Because health benefits come when you switch to vaping completely
- also, vapers should stop smoking completely
