Smoking Cessation Pharmacotherapy Guidelines

Transcription

1 Smoking Cessation Pharmacotherapy Guidelines INTRODUCTION This guideline is based on public health guidance 10 Smoking Cessation Services issued by the National Institute for Health and Clinical Excellence (NICE) in February and NHS Stop Smoking Services: Service and Monitoring Guidance 2010/11 2. The advice addresses the three pharmacotherapies, nicotine replacement therapy (NRT), varenicline (Champix) and bupropion (Zyban) and note that pharmacotherapies work best when combined with support offered by a stop smoking adviser. The number of smokers needed to treat (NNT) with medication and support to prevent one premature death has been shown to be between 38 and 56, which compares favourably with other accepted interventions. All healthcare professionals must exercise their own professional judgement when using guidelines. However any decision to vary from the guideline should be documented in the patient records to include the reason for variance and the subsequent action taken. Nonregistered healthcare workers should follow the guideline implicitly or refer the patient to a registered health professional. BASIC PRINCIPLES NRT, varenicline or bupropion should be offered, as appropriate, to people planning to stop smoking and within the competence of the healthcare adviser. Do not favour one medication over another. The decision should be based on contraindications / potential adverse effects (see below), the client s personal preferences, availability of counselling and support and previous experience of the prescriber. If prescriptions for varenicline or buproprion are required, healthcare staff should refer patients to a doctor. Nicobrevin and NicoBloc should not be used. 2 The PCT specialist nurses in the smoking cessation service, and other Community Practitioner Nurse Prescribers have a limited prescribing list and may write their own prescriptions for NRT but the list does not include varenicline and bupropion. Consequently, patients may be referred to their GP for consideration of bupropion (Zyban) or varenicline (Champix). The nurses will continue to offer behavioural support to the individual whilst taking these preparations, monitor BP where appropriate and monitor side-effects. Other providers may also refer to GP for prescribing bupropion and vareniclicne. Do not use bupropion or varenicline to support assisted reduction to stop strategies. There is some evidence of benefit for using NRT this way for heavy smokers. Do not prescribe NRT, bupropion or varenicline in any combination. Combinations of various formulations of NRT should be considered for people with a high level of dependence or for people who have found single forms inadequate. There is no period of time required between the end of a treatment episode and the start of another if a client has been unsuccessful. Re-assess motivation before represcribing. Prescription charges should be collected from all eligible adults for prescriptions and vouchers (via the community pharmacist) and supply against Patient Group Directions (via the supplier). Refer to the manufacturer s Specific Product Characteristics (SPC) for full prescribing guidance. 3 Page 1 of 6

2 GENERAL PRECAUTIONS Stopping smoking may significantly alter the pharmacokinetics of certain concomitant medications. Further details regarding concomitant drug therapy can be found in the attached table at appendix 1 but this list is not exhaustive and individual drug Summaries of Product Characteristics should be consulted for further details. The effects of stopping smoking take about 1 week to take effect. 4 The MHRA has advised that the most important medicines to consider in those who smoke include theophylline, olanzapine, clozapine, caffeine and warfarin. 4 Diabetes: Nicotine affects carbohydrate metabolism and the absorption of insulin. Therefore patients with diabetes mellitus should be advised to monitor blood sugar more closely than usual when starting NRT. NICOTINE REPLACEMENT THERAPY (NRT) In 2005 the Medicines and Healthcare products Regulatory Agency (MHRA) reviewed the indications and safety for all forms of NRT. 3 All forms of NRT can now be used by smokers in the following categories but the risks and benefits should be clearly explained and they should be strongly encouraged to use behavioural support. Cardiovascular Disease: NRT should be offered where the alternative is the patient resumes smoking. However in patients with cardiovascular disease that is not stable or controlled by treatment, the decision to prescribe should be subject to clinical judgement. For non-medical prescribers this should be made in consultation with the supervising physician (GP or Consultant). The PCT Patient Group Direction for NRT excludes people with unstable cardiovascular disease and clinicians working under the Direction should refer such patients to their GP. Young Persons aged years: Teenagers may safely use NRT but this should not be for longer than 12 weeks without discussing with a doctor, pharmacist or nurse. Health care professionals should ensure children have demonstrated Gillick competency if under 16 years of age. Pregnant and breastfeeding women: The data available is limited, however, the dangers of continuing smoking are well established and are likely to be considerably more damaging to mother and baby than the potential risk of NRT. Pregnant women may have a higher nicotine requirement and this should be taken into account when advising on product strength. Pregnant women should be encouraged to use the NHS Pregnancy Smoking Helpline ( ) and local NHS Sop Smoking Services. 2 Since professional judgement is required in deciding whether to offer NRT, it is recommended that smoking advisers who are not registered health professionals should refer pregnant women to their GP or the Specialist Smoking Advisory Service. Pregnant women should be advised to remove NRT patches before going to bed. GENERAL PRECAUTIONS FOR NRT Patches: For patients with chronic, generalised dermatological disorders such as psoriasis, chronic dermatitis or urticaria it may not be appropriate to use NRT patches. However it may be possible to use patches in patients who have only localised areas affected, but these individual patients should be assessed and monitored by a health professional. Inhalators: Caution using the inhalator in patients with throat or lung disease. Page 2 of 6

3 NRT PRODUCT SELECTION When deciding which of the available therapies to use and in which order, consideration should be made to: Previous usage of smoking cessation aids Contraindications and potential for adverse effects Personal preferences of the smoker. Smokers with early morning craving (within 20 minutes of waking) may prefer a 24 hour patch. Smokers likely to miss the physical sensation of smoking may choose to use an Inhalator. PRESCRIPTIONS Initial prescriptions should last two weeks with subsequent prescriptions given only to people who have demonstrated, on re-assessment, that their quit attempt is continuing. TREATMENT DURATION Although there are no known adverse health effects from long-term use of NRT, the PCT contract for Stop Smoking Services requires assessment at 4 weeks and 12 weeks only. VARENICLINE Varenicline (Champix) is still monitored intensively by the CHM and MHRA. It is psychoactive and for this reason Worcestershire Area Prescribing Committee (APC) does not recommend prescribing by non-medical prescribers unless they have the specific competencies for prescribing drugs that act centrally and may affect mood. It should not be offered to young people under 18 nor to pregnant women, for breastfeeding women refer to summary of Product Characteristics. It should not be used in combination with either bupropion or NRT. Recent studies have questioned a causal link or association between varenicline and suicide, increased risk of depression or suicidal thoughts. However it remains under surveillance as a black triangle drug and the manufacturers Summary of Product Characteristics carries many warnings noting care should be taken with patients with a history of psychiatric illness and patients should be advised of the risk accordingly. 2 Close and regular monitoring for side-effects is essential and patients should be advised to stop the treatment and contact the doctor immediately if they develop suicidal thoughts or behaviour, agitation, depressed mood or changes in behaviour that are of concern to the patient or carer. Psychiatric symptoms have developed in some patients after treatment was stopped. May be offered to people with unstable cardiovascular disorders, subject to clinical judgement. For use in patient with significant renal impairment refer to the Summary of Product Characteristics. Initial prescription should be for 3 4 weeks to last until 2 weeks after the target stop date. See BNF/ SPC for full prescribing details. Subsequent prescriptions should be given only to people who have demonstrated, on reassessment that their quite attempt is continuing. The most common side-effect is mild to moderate nausea that subsides over time. Others include GI disturbances, increased appetite, fatigue, insomnia and dreams and headache which may limit its use. See BNF/ SPC for details. May cause dizziness and somnolence and therefore may influence the ability to drive and use machines. Patients are advised not to drive, operate complex machinery or Page 3 of 6

4 engage in other potentially hazardous activities until it is known whether this medicinal product affects their ability to perform these activities. Discontinuation was associated with an increase in irritability, urge to smoke, depression, and/or insomnia in up to 3% of patients. The prescriber should inform the patient accordingly and discuss or consider the need for dose tapering over one or two weeks. BUPROPION Bupropion (Zyban) is a psychoactive drug related to antidepressants. Worcestershire APC does not recommend prescribing by non-medical prescribers unless they have the specific competencies for prescribing drugs that act centrally and may affect mood. It should not be offered to young people under 18 nor to pregnant or breastfeeding women. It should not be used in combination with either Varenicline or NRT. It should not be offered to people with a history of seizures or eating disorders, bipolar disorder, CNS tumours or during alcohol or benzodiazepine withdrawal. Care should be taken when used in patients with risk factors for seizures including drugs which lower the seizure risk such as tricyclic antidepressants and some antipsychotic medication, alcohol or opiate abuse, history of head trauma, diabetes and use of stimulants and anorectics. Seizure risk is approximately 1 in Bupropion should be offered with care to patients with renal or hepatic impairment, see SPC. Concomitant use of bupropion and monoamine oxidase inhibitors (MAOIs) is contraindicated. Bupropion can increase blood of citalopram which should be avoided for two weeks after stopping. See SPC for details..bupropion is not a substitute antidepressant. The maximum recommended daily dose is 300mg or 150mg daily for those with risk factors for seizure. Should be discontinued and not recommenced in patients who experience a seizure while on treatment. Blood pressure should be measured prior to treatment and monitored during therapy. May be offered to people with unstable cardiovascular disorders, subject to clinical judgement. Initial prescription should be for 3 4 weeks to last until 2 weeks after the target stop date. See BNF/ SPC for full prescribing details. Subsequent prescriptions should be given only to people who have demonstrated, on reassessment that their quite attempt is continuing. Common side-effects are GI disturbances, urticaria, headache, dizziness, fever, insomnia and CNS disturbances. See BNF / SPC for details. Patients should exercise caution before driving or use of machinery until they are reasonably certain bupropion does not adversely affect their performance. REFERENCES 1. Smoking cessation services. NICE public health guidance NHS Stop Smoking Services. Service and Monitoring Guidance 2010/11 Department of Health 3. Varenicline and Bupropion Specific Product Characteristics Drug Safety Update October MHRA 5. TA 38, smoking cessation bupropion and NRT NICE Page 4 of 6

5 APPENDIX 1 These tables are included as a guide and are not exhaustive. It is important that any preemptive dose reduction does not lead to under treatment especially where biochemical markers are not available to measure outcomes e.g. antidepressants. In these circumstances emergence of tolerability related side effects may be a better guide to identifying a need for a dose reduction. Drug Interaction with smoking Clinical significance Management in smoking cessation Benzodiazepines 2 e.g. diazepam, lorazepam, chlordiazepoxide Zolpidem Smoking may cause lower Probably minimal Propranolol Smoking causes lower Beta-blockers general Effects on heart rate and blood pressure from smoking may negate effect of beta-blockers Phenothiazines 2 eg Chlorpromazine Psychiatric symptoms take president Clozapine 2 Will need lower doses Take trough plasma level before conversion to NRT and after 2 weeks, or sooner if side-effects develop. Contact Mental Health Pharmacy Team for guidance. Haloperidol 2 Olanzapine 2 Treat psychiatric symptoms first Antidepressants 2 tricyclics e.g. amitriptyline, imipramine, clomipramine Fluvoxamine 2 Metabolism partly affected Mirtazapine 2 Metabolism partly affected May need lower If experiencing increased side effects Page 5 of 6

6 Drug Interaction with smoking Clinically significant? Management in smoking cessation Duloxetine Smoking causes almost 50% lower than non-smokers Caution may under treat depression as a result Lithium Smoking may reduce xanthine which would decrease lithium excretion Conversion to NRT could increase lithium excretion, lowering Memantine Smoking may increase May need higher doses as level of nicotine reduced Anticonvulsants: carbamazepine, phenytoin, phenobarbital Smoking has been shown to cause lower plasma Not clinically significant Unlikely to require dose adjustment Flecainide Smoking causes lower Insulin Smoking causes increase in of hormones that oppose actions of insulin Insulin dose may need to be reduced as nicotine reduced Theophylline 6 Smoking causes lower Monitor by a health professional Verapamil Smoking may cause lower Unclear on conversion to NRT Warfarin 6 Smoking may cause lower Monitor by a health professional Pentazocine Lower. Smokers may need 50% higher dose May need lower dose Cimetidine / Ranitidine Lower Unclear Unlikely to require dose adjustment Page 6 of 6