Smoking Cessation clinical trials at University of California Health

The prevalence of smoking in the homeless population (70%) is over 4 times that of the general population (15%). Homeless adults have not experienced similar declines in tobacco use as the general population has over the past three decades. Homeless adults are interested in smoking cessation and make quit attempts, but are less successful in quitting smoking than the general population. Trials of group behavioral counseling and pharmacotherapy for smoking cessation have not led to substantial long-term abstinence (i.e., abstinence for 6 months or more), suggesting that these interventions alone are insufficient to improve quit rates among homeless adults. Many homeless adults seek health care in safety net clinics; these clinics could bring cessation interventions to scale. Contingency management is a powerful behavior change intervention that reinforces positive health behaviors through the provision of modest incentives (e.g., cash). In this pilot randomized controlled trial, the investigator will test the feasibility and acceptability of a contingency management intervention that provides incentives for smoking cessation for people experiencing homelessness.

Tobacco and cannabis co-use is a common and growing public health problem, especially in states that have legalized cannabis. There are no pharmacologic treatments for co-occurring tobacco and cannabis use. Co-use may make quitting either substance more difficult, given the synergistic effects of cannabis and nicotine on neurobiological systems that mediate reward and shared cues reinforcing co-use. N-acetylcysteine (NAC), an FDA-approved medication and over-the-counter supplement, has shown promise in animal studies and randomized controlled trials (RCTs) in reducing tobacco and cannabis craving and use.

The focus of this proposal is on expanding access to voluntary smoke-free homes to formerly homeless residents residing in permanent supportive housing, and examining the impact of this intervention on reducing tobacco-caused disparities. In this study, the principal investigator will conduct a multi-site, community-based cluster-randomized wait-list controlled trial of the multi-faceted smoke-free home intervention among 400 permanent supportive housing residents residing in 20 permanent supportive housing sites across the San Francisco Bay Area with the goal of increasing voluntary adoption of smoke-free homes.

This is a randomized, crossover study enrolling experienced dual cannabis-tobacco smokers (N=18) to describe the differences in THC and toxicant exposure, examining pharmacokinetic, subjective, and cardiovascular effects from smoking and vaping dry herb cannabis. This study will also examine the differences in toxicant exposure and cardiovascular disease risk between smoking cannabis and smoking tobacco cigarettes.

Chronic Obstructive Pulmonary Disease (COPD) is a heterogeneous disease that affects only a fraction of those who smoke tobacco. The origin of this variability in susceptibility to develop COPD is unclear, but understanding its underlying biology has important implications for our ability to design suitable preventative and therapeutic strategies for its management. This Department of Defense (DOD) discovery research proposes to develop methodologies and generate preliminary data needed to lay the foundation for a large study that would investigate the underlying biological susceptibility of those who smoke tobacco to develop COPD.