Abstract

Background: In 1996, the US Food and Drug Administration (FDA) approved switching nicotine gum and patch from prescription to over-the-counter (OTC) status. Some expressed concerns that broader availability and lack of physician control might increase persistent use of nicotine replacement therapy (NRT)—that is, use beyond the period specified by the FDA approved label.

Objective: To estimate the incidence of persistent use of OTC nicotine gum and patch for periods of > 3 months, ⩾ 6 months, ⩾ 12 months, and ⩾ 24 months.

Design: Analysis of NRT purchase patterns in data from a population based panel of US households that electronically scanned all household purchases between January 1997 and March 2000.

Subjects: In a national panel of 40 000 US households, 2690 recorded NRT purchases.

Results: Among 805 households that purchased nicotine gum, 2.3% of new purchase incidents led to continuous monthly purchase of gum for ⩾ 6 months. For nicotine patches (2050 households) the percentage was 0.9%. For both gum and patch, the incidence of persistent purchase dropped below 0.4% by 24 months. Allowing one month gaps within a “continuous” purchase run resulted in increased estimates (for gum: 6.7% for ⩾ 6 months and 1.0% for ⩾ 24 months; for patch: 1.7% for ⩾ 6 months and 0.05% for ⩾ 24 months).

Conclusion: Persistent use of nicotine gum and patch is very rare and has not increased with the transition to OTC use, despite removal of physician oversight.