Behavioral Pharmacology of Cannabis and Nicotine

The proposed study will be conducted at the Johns Hopkins Behavioral Pharmacology Research Unit (BPRU). All participants will be healthy adult volunteers who are regular nicotine/tobacco users, and have prior experience with cannabis use. Participants will complete seven outpatient experimental test sessions (completed in a randomized order), under double-blind conditions in which participants will first self-administer smoked cannabis (either active or placebo), followed by nicotine (via a tobacco cigarette or an e-cigarette); there will also be one condition in which participants smoke active cannabis alone (without subsequent nicotine use). Nicotine self-administration will occur in an ad libitum fashion for 5 hours. Nicotine products will be the individual participant's preferred brand of cigarettes or the commercial pod-style e-cigarette the JUUL (pods will contain either 3% or 5% nicotine pods). Active cannabis will contain 10 mg tetrahydrocannabinol (THC) while placebo will contain 0 mg THC. During the ad libitum nicotine/tobacco-use period, various puffing behaviors (e.g., puff volume, puff duration, puff number, inter-puff-interval) will be measured using specialized equipment. Acute subjective effects of cannabis/nicotine, cannabis/nicotine withdrawal symptoms, craving, vital signs, and cognitive/psychomotor performance will also be assessed throughout the experimental sessions.

Inclusion criteria

• Have provided written informed consent
• Be between the ages of 18 and 55
• Be in good general health based on a physical examination, medical history, vital signs, and screening urine and blood tests
• Test negative for drugs of abuse aside from cannabis (via urine sample) and alcohol (via breath sample) at the screening visit and upon arrival for each experimental session.
• Not be pregnant or nursing (if female). All females must have a negative serum pregnancy test at the screening visit and a negative urine pregnancy test at clinic admission.
• Have a body mass index (BMI) in the range of 18 to 36 kg/m2
• Blood pressure at screening visit does not exceed a systolic blood pressure (SBP) of 150 mmHg or a diastolic blood pressure (DBP) of 90 mmHg
• Have not donated blood in the prior 30 days.
• Report prior experience inhaling cannabis.
• Report using cannabis at least 5 times in the past year.
• Smoke ≥5 tobacco cigarettes per day on average in the past month.
• Use an e-cigarette at least 15 of the past 30 days.
• Have a breath carbon monoxide (CO) of >8ppm or urine cotinine >200ng/mL to confirm current nicotine use status.

Exclusion criteria

• Non-medical use of psychoactive drugs (aside from cannabis) other than, nicotine, alcohol, or caffeine in the month prior to the Screening Visit;
• History of or current evidence of significant medical or psychiatric illness which, in the opinion of the investigator or sponsor, will interfere with the study results or the safety of the subject.
• Use of an over-the-counter (OTC), systemic or topical drug(s), herbal supplement(s), or vitamin(s) within 14 days of experimental sessions; which, in the opinion of the investigator or sponsor, will interfere with the study results or the safety of the subject.
• Use of a prescription medication (with the exception of birth control prescriptions) within 14 days of experimental sessions; which, in the opinion of the investigator or sponsor, will interfere with the study results or the safety of the subject.
• History of clinically significant cardiac arrhythmias or vasospastic disease (e.g., Prinzmetal's angina).
• Enrolled in another clinical trial or have received any drug as part of a research study within 30 days prior to dosing.
• Epilepsy or a history of seizures.
• Individuals who have a recent history of traumatic brain injury diagnosed by CT/MRI and have current sequela from prior brain injury, as determined by the study physician
• Individuals with anemia.
• Prior history of allergic or serious adverse reaction to either cannabis or tobacco/nicotine.
• Average use of cannabis more than 2 times per week in the prior 3 months.