Smoking Cessation

Half of all smokers die prematurely of a smoking-related ailment. 90% of smokers aged 45-64 say that they would not smoke given their time again. 4 million smokers a year attempt to quit but only 3% of these succeed. Surveys reveal a “ delusion gap ” as 53% expect to stop within two years, but only 6% manage it. The widespread disaffection with smoking plus the tendency to be deluded about how easy it is to stop justifies promoting chances to stop.¹ The ban on smoking in virtually all enclosed public places and workplaces in England from 1st July 2007 will offer a further window of opportunity.²

Smoking cessation interventions are a cost-effective way of reducing ill health. Quitting at any age provides both immediate and long-term health benefits. Smokers should be advised to stop and offered help and follow-up, with access to a smoking cessation clinic for behavioural support. Nicotine replacement therapy (NRT) and bupropion are effective aids for those smoking more than 10 cigarettes a day. Nicotine replacement therapy is the treatment of choice. Both are more effective when part of a supportive behavioural programme.

NRT can increase the quit rate from 15% (for placebo) to 25% after 9 weeks treatment, and bupropion can increase it to 40% of patients after 9 weeks. Use of NRT and bupropion together does not increase the quit rate any further.³

NICE has recommended (March 2002) that NRT or bupropion should be prescribed only for a smoker who commits to stop. The smoker should be offered advice and encouragement to aid smoking cessation. Initial prescription of NRT or bupropion should be sufficient to last only until 2 weeks after the target stop date.⁴

Therapy is chosen according to likely compliance, contra-indications and the smoker's preferences. If unsuccessful, the NHS should not normally fund a further attempt within 6 months. It should be stopped if smoking is resumed.

Varenicline (Champix) was added to the armamentarium of drugs available on NHS prescription in the UK for smoking cessation in December 2006. The National Institute for Clinical Effectiveness (NICE) have issued a document for consultation and are scheduled to issue definitive guidance later in 2007.⁵ In the interim, the campaigning public health charity Action on Smoking and Health (ASH) have issued guidance to assist healthcare workers in in assessing the role of varenicline in smoking cessation.⁶

Six NRT formulations are available on prescription and most can also be bought over the counter at pharmacies and supermarkets. None of these formulations is more effective than any other. Higher dose gum and patches are more effective in those smoking more than 10 cigarettes a day.

Combining products (eg patch and nasal spray or inhalator) is more effective than single agents.

• Patches 5, 10, 15 mg/16hr (Nicorette); 7, 14, 21mg/24 hr (Niquitin)
• Gum (2 mg, 4mg)
• Nasal spray (0.5mg per puff)
• Inhalation cartridge (10 mg cartridge plus mouthpiece)
• Lozenges (1 mg, 2 mg, 4 mg)
• Sublingual tablets (2 mg)

NRT is most effective with behavioural interventions. NRT reduces but does not completely eliminate the symptoms of withdrawal because it takes a few seconds for nicotine from a cigarette to reach the brain, but minutes for nasal spray, gum, inhalator, sublingual tablet, or lozenge and hours for transdermal patches.⁷
NRT can control the weight gain commonly experienced after cessation. NRT should be continued for eight weeks and can then be stopped immediately.

The risk of dependence on NRT is small. About 5% who quite continue to use nicotine regularly.

Nicotine from NRT is considerably safer than cigarettes, as the patient is not exposed to tar, carbon monoxide and other harmful products. Long term use of NRT is not thought to be associated with any serious harmful effects.
Smokers should be advised not to smoke while using NRT products 9although some gums are licenced for smoking reduction (see below). NRT in pregnancy is justifiable in relation to the risk of continued smoking and is safe in smokers with stable cardiovascular disease.

Contra-indications

Severe cardiovascular disease (severe arrhythmias, post-infarction period); recent CVA (including transient ischaemic attacks)

Cautions

Cardiovascular disease; peripheral vascular disease; hyperthyroidism; diabetes mellitus; phaeochromocytoma, renal impairment, hepatic impairment, gastritis and peptic ulcers

Side-effects

• Nausea
• Dizziness
• Flu-like symptoms
• Palpitations
• Dyspepsia
• Hiccups
• Insomnia
• Vivid dreams
• Myalgia

Bupropion (Zyban) is only available on prescription. Bupropion was developed as an antidepressant but subsequently shown in trials to be effective in smoking cessation. Bupropion is an atypical antidepressant similar to diethylpropion, an appetite suppressant; it inhibits reuptake of dopamine, noradrenaline and serotonin in CNS, and is a non-competitive nicotine receptor antagonist.

Contraindications

Bupropion is contra-indicated in pregnancy or whilst breast feeding. It is also contraindicated in patients with a history of bipolar illness, seizures or of eating disorders, a CNS tumour, alcohol or benzodiazepine withdrawal. The risk of seizures is increased by antidepressants, mefloquine, chloroquine, antipsychotics, quinolones, sedating antihistamines, corticosteroids, theophylline and tramadol. NB allow 14 days after stopping on MAOI.

Cautions

Hepatic cirrhosis, renal impairment; predisposition to seizures; raised BP (monitor weekly if used with nicotine products). May impair performance of skilled tasks (e.g. driving)

Side-effects

The most important side effects are seizures (fits), which occur in about 1 in 1000 patients.
Insomnia and dry mouth commonly occur. About 0.1% of smokers suffer severe hypersensitivity reactions (eg. angio-oedema, bronchospasm and anaphylactic shock), and 3% suffer milder reactions such as rash, urticaria or pruritus.
Rare side effects include: GI disturbances, tremor, anorexia, headache, dizziness, visual disturbance, anxiety, flushing, hallucinations, depersonalisation, seizures, paraesthesia, Stevens-Johnson syndrome, hepatitis, exacerbation of psoriasis.

This is an α4β2 nicotinic acetylcholine receptor partial agonist. This means that it both blocks and stimulates the receptor it is attracted to. The α4β2 receptor is located in the nucleus accumbens area of the brain (the 'pleasure centre'). The stimulatory effect produces a weak nicotine-like effect which reduces the craving for nicotine itself, whilst the blocking effect inhibits the pleasurable effect derived from smoking.

ASH warn that because NICE have not yet issued final guidance, the decision whether to use varenicline as first or second-line treatment should be left to the prescribing clinician after discussion with the patient about the risks and benefits of this relatively new drug. Their guidance however is based on two large randomised phase III clinical trials and the manufacturer's summary of product characteristics (SPC) and is a summation of the best available evidence to date. The trials suggest that varenicline plus counselling is superior to bupropion plus counselling. The British National Formulary currently list varenicline as a smoking cessation aid, but cites nicotine-replacement therapy as being the pharmacological treatment of choice.⁸ Unlike bupropion and NRT, varenicline does not prevent weight gain once smoking has been stopped.

Varenicline should be started 1-2 weeks before the target stop date. Ideally, weekly support from a health professional should be provided. The drug should be initiated at 500mg (one tablet) daily for 3 days, 500 micrograms twice daily for 4 days, then 1 mg twice daily for 11 weeks. If the patient cannot tolerate the higher dose, it can be reduced to 500mg twice daily. A further 12 weeks course of 1mg twice daily can be considered for patients who have stopped smoking but feel they still need further pharmacological support.

Contra-indications

• Pregnancy
• Age under 18

Cautions

• Severe renal impairment
• Breastfeeding
• History of psychiatric illness
• Up to 3% of individuals in the trials complained of irritability, an urge to smoke, depression and/or insomnia on stopping the drug. Patients should be advised of this, and a gradual reduction in dosage towards the end of the course may need to be considered.

Side Effects

The commonest side effect noted in trials was nausea, which occurred in 30% of patients. This usually resolved spontaneously in a few days in patients who continued the drug. It is also helped by taking the tablet with water, but a reduction in dosage to 500mg twice daily was sometimes required. A wide range of other adverse effects were reported, of which the commonest were insomnia, abnormal dreams, headaches and flatulence. Both nausea and abnormal dreams can be reduced by taking the second pill at dinner time or supper time rather than at bedtime.

Nortriptyline, a tricyclic with noradrenergic properties and dopaminergic activity, is effective in cessation therapy, independent of the presence of depressive symptoms.

Clonidine is an alpha agonist that suppresses sympathetic activity and has increased smoking cessation in eight out of nine trials, but serious side effects, including sedation and postural hypotension.

Acupuncture has not been shown to be effective in clinical trials.