33 - Cytisine

Cytisine

526 The Maudsley® Prescribing Guidelines in Psychiatry CHAPTER 4 Preparations and dose People who smoke should set a target stopping date between 1 and 2 weeks after starting varenicline treatment. Those who are not willing or able to set a target date within 1–2 weeks can start treatment and then choose their own stopping date within 5 weeks. Dosage regimens can be found in the treatment algorithm for those people making an attempt to stop smoking at the end of this section (Table 4.21). Adverse effects Very common adverse effects include nausea, strange dreams, sleep disturbance and headache, all occurring in more than 1 in 10 people. Varenicline has no known pharmacokinetic interaction with psychotropic medication. Varenicline does not significantly increase the risk of neuropsychiatric adverse events (including anxiety, depression, aggression, psychosis and suicidal behaviour) when compared with placebo or nicotine patches in patients with or without a history of psychiatric disorders.10,15 Cytisine Cytisine has a similar mechanism of action as varenicline and although it has been available as a smoking cessation aid in Eastern Europe since the 1960s, it has only ­latterly received marketing approval in the UK and other countries. It is indicated for smokers over the age of 18 who are motivated to stop smoking. It is contraindicated during pregnancy and breastfeeding. Clinical effectiveness A Cochrane review10 found moderate-certainty evidence that cytisine is more effective than placebo (RR 1.30) or NRT (RR 1.43). Pooled results from two studies that compared cytisine with varenicline found no significant difference between the two drugs. The review did not identify studies among people with mental illness. Preparations and dose A course of treatment lasts 25 days, which is shorter than the recommended length of treatment for NRT, varenicline and bupropion with a multiple dosing regimen. A stopping date no later than the fifth day of treatment should be aimed for. Dosage regimens can be found in the treatment algorithm for those people making an attempt to stop smoking at the end of this section (Table 4.21). Adverse effects Very common adverse effects include increased appetite, weight gain, dizziness, irritability, mood changes, anxiety, drowsiness, fatigue, abnormal dreams, tachycardia, hypertension, dry mouth and nausea, although the latter may be less common than in patients taking varenicline and more common than in those using NRT. The SPC states that cytisine should not be used with antituberculous drugs.