Smoking and mental health - NCSCT

Smoking cessation interventions for individuals with mental disorders 5
Smokers using these drugs would be expected to compensate their intake of
nicotine from cigarettes to maintain blood levels, but starting these drugs in
smokers using NRT for smoking cessation or abstinence is likely to reduce the
efficacy of the NRT. Nicotine is not known to have any clinically significant
interactions with other medications.
5.4.5 Interactions with caffeine
Caffeine is also metabolised by CYP1A2, up to 60–70% faster in smokers than
non-smokers, 61 and is one probable reason why cigarette smokers tend to drink
more coffee than non-smokers. 69 Caffeine metabolism decreases within 3 or 4
days of stopping smoking and, if coffee consumption continues unchanged, can
lead to symptoms including agitation, irritability or poor concentration which
can be confused with or exacerbate symptoms of both nicotine withdrawal and
mental disorders. High caffeine levels persist weeks or months after quitting
smoking. 70 People who smoke, particularly those with high caffeine intakes,
should therefore be advised to reduce caffeine when they quit smoking; this may
be particularly important for smokers with schizophrenia, among whom very
high serum caffeine levels have been reported. 71
5.4.6 Nicotine withdrawal symptoms
Abrupt cessation or reduction in nicotine use in people who smoke regularly
results in symptoms of nicotine withdrawal, which can include dysphoric or
depressed mood, insomnia, irritability, frustration, anger, anxiety, difficulty
concentrating and restlessness. 72 These symptoms tend to be more severe in
smokers with SMI, 73–76 and their non-specificity can result in misattribution to
mental disorders and inappropriate treatment responses. A study of smokers
with schizophrenia admitted to a smoke-free hospital found higher levels of
agitation in those with greater nicotine dependence, and a significant reduction
in agitation in those who received a 21 mg nicotine patch relative to a placebo. 77
It is therefore particularly important to ensure that adequate doses of NRT are
provided to people with mental disorders who smoke during quit attempts or
other abstention from smoking.
5.4.7 Effects of antipsychotic medication on smoking cessation
Antipsychotic medication can also influence smoking behaviour. Smokers using
‘atypical’ antipsychotics such as clozapine, as opposed to first-generation
(‘typical’) treatments such as haloperidol, are more likely to quit smoking. 29
Clozapine treatment is also associated with reduced smoking, particularly in
© Royal College of Physicians 2013 95