1. Nicotine Replacement Therapy (NRT)
Mechanism:
- Provides a controlled dose of nicotine to reduce withdrawal symptoms and cravings, easing the transition to complete abstinence from nicotine.
Forms:
- Patches
- Gum
- Lozenges
- Nasal spray
- Inhalers
Common Side Effects:
- Skin irritation (patches)
- Mouth and throat irritation (gum, lozenges, inhalers)
- Nasal irritation (nasal spray)
- Gastrointestinal disturbances (nausea, hiccups)
Contraindications:
- Severe eczema or psoriasis (patches)
- Jaw problems or dentures (gum)
- Nasal disorders (nasal spray)
- Severe asthma or COPD (inhalers)
2. Bupropion (Zyban)
Mechanism:
- Atypical antidepressant that inhibits the reuptake of dopamine and norepinephrine, reducing withdrawal symptoms and the pleasure associated with smoking.
Common Side Effects:
- Insomnia
- Dry mouth
- Headache
- Dizziness
- Increased risk of seizures
Contraindications:
- Seizure disorders
- History of anorexia or bulimia
- Concurrent use of monoamine oxidase inhibitors (MAOIs)
- Abrupt discontinuation of alcohol or sedatives
3. Varenicline (Champix)
Mechanism:
- Partial agonist at nicotinic acetylcholine receptors, reducing cravings and withdrawal symptoms while also blocking the rewarding effects of nicotine.
Common Side Effects:
- Nausea
- Insomnia
- Abnormal dreams
- Headache
- Mood changes (depression, agitation, suicidal thoughts; monitoring recommended)
Contraindications:
- History of serious psychiatric conditions (use with caution)
- Severe renal impairment (dose adjustment needed)
4. Nortriptyline (Allegron)
Mechanism:
- Tricyclic antidepressant inhibits the reuptake of norepinephrine and serotonin, reducing withdrawal symptoms.
Common Side Effects:
- Dry mouth
- Constipation
- Urinary retention
- Blurred vision
- Weight gain
- Drowsiness
- Risk of cardiac arrhythmias
Contraindications:
- Recent myocardial infarction
- Concurrent use of MAOIs
- Severe cardiac disease
5. Clonidine (Catapres)
Mechanism:
- Alpha-2 adrenergic agonist that reduces withdrawal symptoms by decreasing sympathetic outflow.
Common Side Effects:
- Dry mouth
- Drowsiness
- Dizziness
- Constipation
- Hypotension
Contraindications:
- Severe cardiovascular disease
- History of severe depression
- Hypersensitivity to clonidine
Vaping (E-cigarettes)
Mechanism:
- Provides nicotine in vapor form, mimicking the act of smoking without combusting tobacco, which reduces exposure to many harmful chemicals found in cigarette smoke.
Common Side Effects:
- Throat and mouth irritation
- Coughing
- Nausea
- Headache
- Potential lung injury (especially with non-regulated products)
Concerns and Contraindications:
- Long-term health effects are still largely unknown.
- Not recommended for non-smokers, pregnant women, or adolescents.
- Risk of nicotine addiction.
- Potential contamination with harmful substances (especially in unregulated products).
Summary of Key Points
- NRT: Safe and widely used, but should be chosen based on individual medical conditions.
- Bupropion: Effective for many but contraindicated in seizure-prone individuals and those with certain psychiatric conditions and seizures.
- Varenicline: Effective but requires monitoring for psychiatric symptoms.
- Nortriptyline and Clonidine: Secondary options with specific uses and contraindications.
- Vaping: An alternative to smoking, but with potential health risks and unknown long-term effects.
Considerations
- Medication choice should be individualized based on patient preferences, medical history, and potential side effects.
- Behavioural support and counselling are crucial components of a comprehensive smoking cessation program.
- Monitoring for side effects and adherence to the treatment plan are essential for success.
Combining pharmacotherapy with behavioural support offers the best outcomes for smoking cessation.