Acute effects of nicotine on physiological and subjective sexual arousal in nonsmoking men: a randomized, double-blind, placebo-controlled trial

Abstract

Introduction: Chronic nicotine treatment has deleterious effects on vascular functioning and catecholamine modulation, which may compromise erectile functioning. Evidence that long-term cigarette smoking is an independent risk factor for introducing impotence is robust. However, limited studies have focused on the acute effects of smoking on physiological sexual response, and none have investigated the deleterious effects of isolated nicotine on human sexual arousal. Consequently, pathophysiological underpinnings of tobacco-induced-and particularly, nicotine-induced-erectile dysfunction are not well understood.

Aim: To provide the first empirical examination of the acute effects of isolated nicotine on sexual arousal in nonsmoking men.

Methods: Twenty-eight sexually functional heterosexual men (mean age 21 years), each with less than 100 direct exposures to nicotine, participated in a double-blind, randomized, placebo-controlled, crossover trial. Participants received either Nicorette polacrilex gum (SmithKline Beecham Consumer Healthcare, Pittsburgh, PA, USA) (6 mg; approximately equivalent to smoking one high-yield cigarette) or placebo gum, matched for appearance, taste, and consistency, approximately 40 minutes prior to viewing an erotic film.

Main outcome measures: Physiological (circumferential change via penile plethysmography) and subjective (continuous self-report) sexual responses to erotic stimuli were examined, as well as changes in mood.

Results: Nicotine significantly reduced erectile responses to the erotic films (P = 0.02), corresponding to a 23% reduction in physiological sexual arousal. This occurred in 16 of 20 men with valid physiological recordings. Nicotine had no significant effect on continuous subjective ratings of sexual arousal (P = 0.70) or on mood (all Ps > 0.05).

Conclusions: Isolated nicotine can significantly attenuate physiological sexual arousal in healthy nonsmoking men. These findings have implications for elucidating physiological mechanisms responsible for the effects of nicotine on sexual dysfunction, and for assisting public health policy in considering the deleterious effects of nicotine on sexual health.

Figure 1

Physiological sexual arousal in response to drug administration. (A) Mean percent full erection (PFE) in 5-second intervals across the neutral and various erotic film stimuli during nicotine and placebo conditions. (B) Mean (±standard error of the mean [SEM]) PFE between the neutral stimulus and the entire erotic film stimulus (average of petting, oral sex, intercourse) during nicotine and placebo conditions. Untransformed PFE values are depicted in order to facilitate visual interpretation of the data; all analyses were conducted using square root transformations.

Figure 2

Subjective sexual arousal in response to drug administration. (A) Mean percent of maximum possible arousal in 5-second intervals across the neutral and various erotic film stimuli during nicotine and placebo conditions. (B) Mean (±standard error of the mean [SEM]) percent of maximum possible subjective arousal between the neutral stimulus and the entire erotic film stimulus (average of petting, oral sex, intercourse) during nicotine and placebo conditions.