Overview
This study is designed to investigate the effects of a beta-adrenergic antagonist (Propranolol; 40 mg IR) and nicotine patch (14 mg) administered alone and in combination on neurobiological and behavioral responses to smoking cues in ongoing cigarette smokers. This is a basic experimental study in humans and participants will not take these medications for an extended period or make a cessation attempt as part of their involvement in this research project.
Description
Cigarette use remains a serious public health problem in the United States and worldwide. Effective pharmacological interventions for smoking cessation exist, but these medications primarily target nicotine withdrawal and smoking reinforcement. The cues and contexts associated with smoking also play an important role in driving smoking behavior, but evidence is extremely mixed whether existing interventions can effectively attenuate smoking urges and behavior in response to these cues and contexts.
In a previous pilot trial, the investigators demonstrated that propranolol suppressed smoking cue reactivity and brain activation across a constellation of brain regions implicated in nicotine dependence. Here, the investigators seek to extend this work by examining effects when the drug is administered in combination with an established treatment targeting withdrawal and reinforcement (i.e., nicotine patch).
Following consent and screening/baseline activities, participants will attend four neuroimaging appointments each lasting approximately 5 hours. Participants will be fitted with a nicotine or placebo patch, fed a standard meal and then administered propranolol or placebo. Participants will complete questionnaires and have their heart rate/blood pressure monitored throughout the visit. During the MRI scan, participants will be asked to complete both resting scans and task-based scans during which participants will view images of smoking and non-smoking objects and scenes.
Eligibility
Inclusion Criteria:
- Generally healthy
- Age 21-60
- Right-handed using a three-item scale
- Daily smoker of ≥ 5 cigarettes/day delivering 0.5 mg nicotine (FTC)
- Smoking regularly for ≥ 1 year, with stable smoking for the past 6 months
- Afternoon expired Carbon Monoxide (CO) concentration ≥ 6 ppm and/or morning urinary cotinine >100 ng/ml
- Must identity at least 4 different smoking locations used in a typical week
- Able to read and understand English
Exclusion Criteria:
- Inability to attend all required sessions
- Significant health problems that would preclude active participation
- Presence of conditions that would make MRI unsafe (e.g. pacemaker) or (e.g. weight and body shape)
- Current use of psychoactive medications/drugs as indicated by self-report or urine screen
- Positive breath alcohol concentration
- Pregnant, breastfeeding, or planning to become pregnant during the course of the study (females)
- Problems with vision that cannot be corrected with contacts or glasses
- Current regular use of smokeless tobacco, smoking cessation medications, or other nicotine containing products (e.g. electronic cigarettes)
- Current use of beta-adrenergic medications (e.g. beta-blockers) or other blood pressure medications
- Systolic blood pressure < 90 mmHg or diastolic blood pressure < 60 mmHg (sitting or standing)
- Abnormal EKG
- Presence of severe anemia
- Presence of electrolyte imbalance that could impact blood pressure
- Presence of any other contraindications for propranolol or nicotine patch (e.g. cardiovascular disease, bronchial asthma, prior allergic reactions, diabetes)