Nicotine replacement therapy

Nicotine replacement therapy (NRT) gives nicotine without smoke, through patches, gum, lozenges and similar products, to help people quit. It works, especially as a patch plus a fast-acting form. In short-term quitting trials, serious heart problems were not clearly more common than with placebo, though the data are imprecise and minor heart effects are more common.

If you are quitting smoking, combine a nicotine patch with a fast-acting form, or use varenicline, cytisine or a nicotine e-cigarette, which work at least as well. If you are pregnant, decide with a clinician.

How well it works

A Cochrane network meta-analysis of the quitting options found high-certainty evidence that combination nicotine replacement (a patch plus a fast-acting form) ranks among the most effective treatments, alongside varenicline, cytisine and nicotine e-cigarettes.^[1] In a large head-to-head trial funded by the makers of varenicline and bupropion, which randomised 8,144 smokers in 16 countries, end-of-treatment continuous abstinence was 23.4% on the nicotine patch against 12.5% on placebo, while varenicline did better than the patch at 33.5%.^[2] For smokers trying to quit, nicotine e-cigarettes help more people stop than nicotine replacement (high-certainty evidence).^[3]

Is it safe for the heart?

Probably, in the short term, but the data are imprecise. In randomised trials of nicotine replacement (about half comparing a nicotine patch with a placebo patch, mostly in smokers trying to quit), serious cardiovascular events such as heart attack, stroke and cardiovascular death were rare and not clearly more common than with placebo. Events were too few to rule out a modest risk, and that review was written in collaboration with a tobacco company.^[4] A 2014 network meta-analysis found cardiovascular events overall about twice as common with nicotine replacement, mostly less serious ones, with no clear excess of major events.^[5] A patch gives a transient, mild rise in heart rate and blood pressure. Whatever its risks, it avoids the smoke, which does most of the cardiovascular damage.

Pregnancy

Smoking in pregnancy raises the risk of fetal growth restriction, low birth weight and perinatal death. Obstetric guidance is to advise stopping every tobacco product, e-cigarettes included, and to tailor care, offering psychosocial and behavioural support and medication.^[6] In trials with pregnant smokers, nicotine replacement showed no clear harm to babies, though its benefit for quitting is uncertain (low-certainty evidence).^[7]

Nicotine patches for other reasons

Nicotine patches are sometimes promoted for memory or longevity. A single dose of nicotine gives small gains in some laboratory tests of fine motor skill, alertness, attention speed and short-term memory, but long-term daily use has not shown a lasting benefit: in a two-year trial of 348 people aged 55–90 with mild cognitive impairment who had not regularly used tobacco or nicotine in the past year, a daily nicotine patch (up to 21 mg) did not improve memory or overall clinical status compared with placebo (results posted on the trial registry, not yet published in a journal).^[8] The longevity case rests on one mouse study, and there is no human trial. Anyone with a history of nicotine addiction should be especially wary. Nicotine is no reliable performance aid either: in exercise studies most measures showed no effect, and in one small study a patch raised core temperature slightly during exercise, which its authors read as a heat-illness risk.^[9]^[10]

What to do

To quit smoking, use a patch together with a fast-acting form (gum, lozenge or similar), or use varenicline, cytisine or a nicotine e-cigarette.
Don't use nicotine patches as a memory, performance or longevity aid, and avoid nicotine before endurance exercise in the heat.
If you are pregnant and smoke, discuss nicotine replacement with your clinician as part of a quit plan.