Exogenous progesterone for smoking cessation in men and women: a pilot double-blind, placebo-controlled randomized clinical trial.

Abstract

BACKGROUND AND AIMS\nIn some clinical studies men and women have been found to differ in their ability to quit smoking, perhaps as a result of progesterone. The primary aim of this study was to provide a preliminary test of whether progesterone (PRO), compared with placebo (PBO), was more effective for smoking cessation in men and women.\n\n\nDESIGN\nPilot double-blind, placebo-controlled randomized clinical trial.\n\n\nSETTING\nMinneapolis/St Paul metro area, Minnesota, USA.\n\n\nPARTICIPANTS\nA total of 216 participants were randomized, including 113 men (18-60\xa0years; PRO\xa0=\xa056, PBO\xa0=\xa057) and 103 women (18-50\xa0years, pre-menopausal with self-reported regular menstrual cycles; PRO\xa0=\xa051, PBO\xa0=\xa052).\n\n\nINTERVENTION\nParticipants were randomized (1\xa0:\xa01 within sex group) to either PRO (200\xa0mg twice daily) or PBO. Participants were assigned a quit date approximately 7\xa0days after starting medication (luteal phase for women) and were followed for 12\xa0weeks to assess relapse.\n\n\nMEASUREMENTS\nThe primary outcome was self-reported 7-day point prevalence abstinence (PPA) at week 4. Secondary outcomes included 7-day PPA at weeks 8 and 12, prolonged abstinence, continuous abstinence, urine cotinine <\xa050\xa0ng/ml, expired carbon monoxide ≤\xa05\xa0parts per million (p.p.m.) and days to relapse.\n\n\nFINDINGS\nThere was a significant difference in 7-day PPA at week 4 among women [PRO: 18 (35.3%) versus PBO: 9 (17.3%), odds ratio (OR)\xa0=\xa02.61, 95% confidence interval (CI)\xa0=\xa01.04, 6.54, P\xa0=\xa00.041], but not among men [PRO: 13 (23.2%) versus PBO: 12 (21.1%), 1.13 (0.47, 2.76), P\xa0=\xa00.782]. There was some evidence that PRO delayed relapse in women (days to relapse; PRO: 20.5\xa0±\xa029.6 versus PBO: 14.3\xa0±\xa026.8, P\xa0=\xa00.03) but not in men (PRO: 13.4\xa0±\xa025.9 versus PBO: 13.3\xa0±\xa023.8, P\xa0=\xa00.69).\n\n\nCONCLUSIONS\nOral micronized progesterone may aid smoking cessation in women.