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"Milavetz, Gary"
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Patterns of Marijuana Use and Health Impact: A Survey Among Older Coloradans
2019
Access to recreational and medical marijuana is common in the United States, particularly in states with legalized use. Here, we describe patterns of recreational and medical marijuana use and self-reported health among older persons using a geographically sampled survey in Colorado. The in-person or online survey was offered to community-dwelling older persons aged above 60 years. We assessed past-year marijuana use including recreational, medical, or both; methods of use; marijuana source; reasons for use; sociodemographic and health factors; and self-reported health. Of 274 respondents (mean age = 72.5 years, 65% women), 45% reported past-year marijuana use. Of these, 54% reported using marijuana both medically and recreationally. Using more than one marijuana method or preparation was common. Reasons for use included arthritis, chronic back pain, anxiety, and depression. Past-year marijuana users reported improved overall health, quality of life, day-to-day functioning, and improvement in pain. Odds of past-year marijuana use decreased with each additional year of age. The odds were lower among women and those with higher self-reported health status; odds of use were higher with past-year opioid use. Older persons with access to recreational and medical marijuana described concurrent use of medical and recreational marijuana, use of multiple preparations, and overall positive health impacts.
Journal Article
Cannabinoid disposition in oral fluid after controlled vaporizer administration with and without alcohol
by
Jang, Moonhee
,
Anizan, Sébastien
,
Hartman, Rebecca L.
in
Alcohol
,
Blood & organ donations
,
Breath tests
2015
Oral fluid (OF) is an advantageous matrix for cannabis detection, with on-site tests available for roadside drug-impaired driver screening. Limited data exist for device performance following consumption of vaporized cannabis, which reduces exposure to harmful combustion by-products. We assessed cannabinoid OF disposition, with and without alcohol, and evaluated on-site Dräger
®
DrugTest 5000 performance (Dräger) following controlled vaporization of cannabis. Forty-three cannabis smokers (≥1×/3 months, ≤3 days/week) reported 10–16 h prior to dosing, and drank placebo or low-dose alcohol [target ~0.065 % peak breath-alcohol concentration (BrAC)] 10 min prior to inhaling 500 mg of placebo, low-dose [2.9 % ∆
9
-tetrahydrocannabinol (THC)], or high-dose (6.7 % THC) vaporized cannabis (within-subjects; six possible alcohol–cannabis combinations; 19 completers). BrAC readings and OF (Quantisal™, Dräger) were collected before and up to 8.3 h post-dose. Median [range] maximum OF concentrations (
C
max
) for low and high doses (no alcohol,
N
= 19) were 848 [32.1–18,230] and 764 [25.1–23,680] µg/l THC; 6.0 [0–100] and 26.8 [1.0–1106] µg/l cannabidiol; 54.4 [1.8–941] and 29.7 [0–766] µg/l cannabinol; and 24.1 [0–686] and 18.0 [0–414] ng/l 11-nor-9-carboxy-THC (THCCOOH). Lack of significant differences in THC concentration between low doses and high doses indicated that participants may have titrated doses. THC, cannabidiol and cannabinol
C
max
values were immediately post-inhalation, but metabolite THCCOOH
t
max
showed interindividual variability. Concurrent alcohol did not affect OF cannabinoid concentrations or on-site test sensitivity. With a THC confirmation cutoff of 5 µg/l, Dräger sensitivity, specificity, and efficiency were 60.8, 98.2, and 82.5 %. Dräger had lower sensitivity after 6.7 % THC vaporization (53.8 %, THC ≥2 µg/l confirmation cutoff) than reported following smoking a 6.8 % THC cigarette, but high specificity (99.3 %) and comparable efficiency (65.0 %). Vaporized THC bioavailability may be lower than that when smoked. Confirmation cutoff, time course, intake histories, and additional cannabinoid analytes also affect OF interpretation.
Journal Article
Controlled Cannabis Vaporizer Administration: Blood and Plasma Cannabinoids with and without Alcohol
by
Huestis, Marilyn A
,
Spurgin, Andrew
,
Brown, Timothy L
in
Administration, Oral
,
Adult
,
Agreements
2015
Increased medical and legal cannabis intake is accompanied by greater use of cannabis vaporization and more cases of driving under the influence of cannabis. Although simultaneous Δ(9)-tetrahydrocannabinol (THC) and alcohol use is frequent, potential pharmacokinetic interactions are poorly understood. Here we studied blood and plasma vaporized cannabinoid disposition, with and without simultaneous oral low-dose alcohol.
Thirty-two adult cannabis smokers (≥1 time/3 months, ≤3 days/week) drank placebo or low-dose alcohol (target approximately 0.065% peak breath-alcohol concentration) 10 min before inhaling 500 mg placebo, low-dose (2.9%) THC, or high-dose (6.7%) THC vaporized cannabis (6 within-individual alcohol-cannabis combinations). Blood and plasma were obtained before and up to 8.3 h after ingestion.
Nineteen participants completed all sessions. Median (range) maximum blood concentrations (Cmax) for low and high THC doses (no alcohol) were 32.7 (11.4-66.2) and 42.2 (15.2-137) μg/L THC, respectively, and 2.8 (0-9.1) and 5.0 (0-14.2) μg/L 11-OH-THC. With alcohol, low and high dose Cmax values were 35.3 (13.0-71.4) and 67.5 (18.1-210) μg/L THC and 3.7 (1.4-6.0) and 6.0 (0-23.3) μg/L 11-OH-THC, significantly higher than without alcohol. With a THC detection cutoff of ≥1 μg/L, ≥16.7% of participants remained positive 8.3 h postdose, whereas ≤21.1% were positive by 2.3 h with a cutoff of ≥5 μg/L.
Vaporization is an effective THC delivery route. The significantly higher blood THC and 11-OH-THC Cmax values with alcohol possibly explain increased performance impairment observed from cannabis-alcohol combinations. Chosen driving-related THC cutoffs should be considered carefully to best reflect performance impairment windows. Our results will help facilitate forensic interpretation and inform the debate on drugged driving legislation.
Journal Article
Qualitative Analysis of Cannabis Use Among Older Adults in Colorado
2019
Background
Although the rate of cannabis use by older adults is increasing more quickly than all other age groups, little is known about the reasons why older adults use cannabis and the outcomes they experience.
Objective
The objective of this study was to identify the most salient themes concerning the use of medical and recreational cannabis by older adults living in Colorado. Specifically, we sought to (1) characterize perceptions of cannabis use by users and non-users, (2) determine how older adults access cannabis, and (3) explicate both positive and negative outcomes associated with cannabis use.
Methods
Between June and November 2017, we conducted 17 focus groups in senior centers, health clinics, and cannabis dispensaries in 15 Colorado cities. Participants included 136 persons aged over 60 years who were both users and non-users of cannabis. We coded and analyzed session transcripts using thematic analysis with NVivo software.
Results
We identified 16 codes from which five main themes emerged. These themes included: a lack of education and research about cannabis, a lack of provider communication, access to medical cannabis, the outcomes of cannabis use, and a reluctance to discuss cannabis use.
Conclusions
Older adults want more information about cannabis and desire to communicate with their healthcare providers. Older adults who used cannabis for medical purposes reported positive outcomes but highlighted difficulties in accessing medical cannabis. Older adults in Colorado also revealed how a stigma continues to be attached to using cannabis.
Journal Article
Cannabidiol (CBD) Use by Older Adults for Acute and Chronic Pain
2021
Legalization of cannabidiol (CBD) products has ignited interest in clinical practice and research. One desired indication includes possible pain-relieving effects of CBD. The purposes of the current article are to (1) clarify terminology relevant to cannabinoids; (2) explain and understand the pharmacotherapeutics of CBD; (3) examine research of the current use of CBD by older adults for treating pain; (4) discuss safety considerations with using CBD products; and (5) provide best practice recommendations for clinicians as they advise their older adult patients. A review of the literature demonstrated mixed results on the efficacy of CBD in relieving pain in older adults. There is inconsistency in the labeling of over-the-counter CBD products that can result in safety issues and will require more federal quality control. Likewise, gaps in knowledge regarding safety and efficacy of CBD use in older adults are vast and require further research. [Journal of Gerontological Nursing, 47(7), 6–15.]
Journal Article
Cannabidiol
2021
Legalization of cannabidiol (CBD) products has ignited interest in clinical practice and research. One desired indication includes possible pain-relieving effects of CBD. The purposes of the current article are to (1) clarify terminology relevant to cannabinoids; (2) explain and understand the pharmacotherapeutics of CBD; (3) examine research of the current use of CBD by older adults for treating pain; (4) discuss safety considerations with using CBD products; and (5) provide best practice recommendations for clinicians as they advise their older adult patients. A review of the literature demonstrated mixed results on the efficacy of CBD in relieving pain in older adults. There is inconsistency in the labeling of over-the-counter CBD products that can result in safety issues and will require more federal quality control. Likewise, gaps in knowledge regarding safety and efficacy of CBD use in older adults are vast and require further research. [Journal of Gerontological Nursing, 47(7), 6–15.]
Journal Article
Mechanisms of cannabis impairment: Implications for modeling driving performance
by
McGehee, Daniel V.
,
Milavetz, Gary
,
Brown, Timothy L.
in
Analgesics
,
Automobile Driving
,
breathing
2021
•Disparity between the cannabis products legally available and those researched.•Low THC potencies in research compared to personal use may limit generalizability.•Paucity of research on novel modes of use with different pharmacokinetic timelines.•More research is needed to better understand the impacts on driving performance.
Past research on cannabis has been limited in scope to THC potencies lower than legally available and efforts to integrate the effects into models of driving performance have not been attempted to date. The purpose of this systematic review is to understand the implications for modeling driving performance and describe future research needs. The risk of motor vehicle crashes increases 2-fold after smoking marijuana. Driving during acute cannabis intoxication impairs concentration, reaction time, along with a variety of other necessary driving-related skills. Changes to legislation in North America and abroad have led to an increase in cannabis’ popularity. This has given rise to more potent strains, with higher THC concentrations than ever before. There is also rising usage of novel ingestion methods other than smoking, such as oral cannabis products (e.g., brownies, infused drinks, candies), vaping, and topicals. The PRISMA guidelines were followed to perform a systematic search of the PubMed database for peer-reviewed literature. Search terms were combined with keywords for driving performance: driving, performance, impairment. Grey literature was also reviewed, including congressional reports, committee reports, and roadside surveys. There is a large discrepancy between the types of cannabis products sold and what is researched. Almost all studies that used inhalation as the mode of ingestion with cannabis that is around 6% THC. This pales in comparison to the more potent strains being sold today which can exceed 20%. Which is to say nothing of extracts, which can contain 60% or more THC. Experimental protocol is another gap in research that needs to be filled. Methodologies that involve naturalistic (real world) driving environments, smoked rather than vaporized cannabis, and non-lab certified products introduce uncontrollable variables. When considering the available literature and the implications of modeling the impacts of cannabis on driving performance, two critical areas emerge that require additional research: The first is the role of cannabis potency. Second is the route of administration. Does the lower peak THC level result in smaller impacts on performance? How long does potential impairment last along the longer time-course associated with different pharmacokinetic profiles. It is critical for modeling efforts to understand the answers to these questions, accurately model the effects on driver performance, and by extension understand the risk to the public.
Journal Article
Effect of Blood Collection Time on Measured Delta^sup 9^-Tetrahydrocannabinol Concentrations: Implications for Driving Interpretation and Drug Policy
2016
In driving-under-the-influence cases, blood typically is collected approximately 1.5- 4 h after an incident, with unknown last intake time. This complicates blood Δ^sup 9^-tetrahydrocannabinol (THC) interpretation, owing to rapidly decreasing concentrations immediately after inhalation. We evaluated how decreases in blood THC concentration before collection may affect interpretation of toxicological results. Adult cannabis smokers (≥1×/3 months, ≤3 days/week) drank placebo or low-dose alcohol (approximately 0.065% peak breath alcohol concentration) 10 min before inhaling 500 mg placebo, 2.9%, or 6.7% vaporized THC (within-individuals), then took simulated drives 0.5-1.3 h postdose. Blood THC concentrations were determined before and up to 8.3 h postdose (limit of quantification 1 µg/L). In 18 participants, observed C^sub max^ (at 0.17 h) for active (2.9 or 6.7% THC) cannabis were [median (range)] 38.2 µg/L (11.4-137) without alcohol and 47.9 µg/L (13.0 -210) with alcohol. THC C^sub max^ concentration decreased 73.5% (3.3%- 89.5%) without alcohol and 75.1% (11.5%- 85.4%) with alcohol in the first half-hour after active cannabis and 90.3% (76.1%-100%) and 91.3% (53.8%-97.0%), respectively, by 1.4 h postdose. When residual THC (from previous self-administration) was present, concentrations rapidly decreased to preinhalation baselines and fluctuated around them. During-drive THC concentrations previously associated with impairment (≥8.2 µg/L) decreased to median <5 µg/L by 3.3 h postdose and >2 µg/L by 4.8 h postdose; only 1 participant had THC ≥5 µg/L after 3.3 h. Forensic blood THC concentrations may be lower than common per se cutoffs despite greatly exceeding them while driving. Concentrations during driving cannot be back-extrapolated because of unknown time after intake and interindividual variability in rates of decrease.
Journal Article
Effect of Blood Collection Time on Measured Δ9-Tetrahydrocannabinol Concentrations: Implications for Driving Interpretation and Drug Policy
by
Huestis, Marilyn A
,
Spurgin, Andrew
,
Brown, Timothy L
in
Accidents, Traffic
,
Adult
,
Automobile Driving
2016
In driving-under-the-influence cases, blood typically is collected approximately 1.5-4 h after an incident, with unknown last intake time. This complicates blood Δ(9)-tetrahydrocannabinol (THC) interpretation, owing to rapidly decreasing concentrations immediately after inhalation. We evaluated how decreases in blood THC concentration before collection may affect interpretation of toxicological results.
Adult cannabis smokers (≥1×/3 months, ≤3 days/week) drank placebo or low-dose alcohol (approximately 0.065% peak breath alcohol concentration) 10 min before inhaling 500 mg placebo, 2.9%, or 6.7% vaporized THC (within-individuals), then took simulated drives 0.5-1.3 h postdose. Blood THC concentrations were determined before and up to 8.3 h postdose (limit of quantification 1 μg/L).
In 18 participants, observed Cmax (at 0.17 h) for active (2.9 or 6.7% THC) cannabis were [median (range)] 38.2 μg/L (11.4-137) without alcohol and 47.9 μg/L (13.0-210) with alcohol. THC Cmax concentration decreased 73.5% (3.3%-89.5%) without alcohol and 75.1% (11.5%-85.4%) with alcohol in the first half-hour after active cannabis and 90.3% (76.1%-100%) and 91.3% (53.8%-97.0%), respectively, by 1.4 h postdose. When residual THC (from previous self-administration) was present, concentrations rapidly decreased to preinhalation baselines and fluctuated around them. During-drive THC concentrations previously associated with impairment (≥8.2 μg/L) decreased to median <5 μg/L by 3.3 h postdose and <2 μg/L by 4.8 h postdose; only 1 participant had THC ≥5 μg/L after 3.3 h.
Forensic blood THC concentrations may be lower than common per se cutoffs despite greatly exceeding them while driving. Concentrations during driving cannot be back-extrapolated because of unknown time after intake and interindividual variability in rates of decrease.
Journal Article
Demonstration of In Vivo Bioequivalence of a Generic Albuterol Metered-Dose Inhaler to Ventolin
2000
To use histamine bronchoprovocation and bioassay statistical procedures to evaluate the in vivo bioequivalence of a generic albuterol metered-dose inhaler (MDI).
A randomized, double-blind, balanced, crossover design was used to determine the potency of each generic albuterol MDI actuation relative to Ventolin (Glaxo Wellcome; Research Triangle Park, NC) administration. One treatment was administered on each of 4 study days. A histamine bronchoprovocation procedure was initiated 1.25 h before and 15 min after administration of the study treatment.
Twenty-four nonsmoking subjects with mild-to-moderate asthma were studied (18 to 65 years of age; FEV1, > 60% of predicted; and provocative concentration of histamine causing a 20% fall in FEV1[ PC20], ≤ 8 mg/mL at screening).
One and four actuations (90 and 360 μg, respectively) of the generic MDI and of Ventolin MDI. Placebo inhalers were used to maintain blinding of inhaler and doses.
The primary outcome variable was histamine PC20 measured after study treatment administration. A significant dose-effect relationship was present (p < 0.0001). Deviation from parallelism of the generic and Ventolin dose-response curves (p = 0.95) and differences in overall mean response between the two formulations (p = 0.68) were not significant. Using Finney 2 × 2 bioassay statistical procedures, we estimated that one actuation of the generic albuterol MDI was equivalent to 1.01 puffs of Ventolin (90% confidence interval, 0.69 to 1.50).
The generic albuterol MDI delivers a quantity of albuterol to the β2-receptor site in the lung that is the bioequivalent to Ventolin. Further, this study reinforces the validity of this statistical methodology for determining in vivo bioequivalence.
Journal Article