Acute analgesic effect of nicotine vaping using three experimental pain induction tasks: a randomized, placebo-controlled laboratory study.

RATIONALE: Pain and nicotine use are co-occurring conditions with a significant impact on health. Experimental evidence supports an acute analgesic effect of nicotine which may reinforce nicotine use among those with chronic pain. Evidence for nicotine analgesia have primarily been gathered in combustible cigarette users and have not been extended to electronic nicotine delivery systems (ENDS or vaping). Furthermore, the mechanisms of nicotine analgesia in humans are not well understood. OBJECTIVES: Assess the effect of acute vaped nicotine on subjective and behavioral indices of pain sensitivity using three tasks designed to probe distinct mechanisms of analgesia. METHODS: This study recruited ENDS users (N = 86) to undergo a paced vaping protocol followed by pain tasks in counterbalanced order. Across four sessions, participants vaped e-liquid containing nicotine or placebo, and flavor or no-flavor in a 2 × 2 within-subject design. Assessments included cold pressor, submaximal effort tourniquet to induce ischemic pain, and temporal summation of heat pain, an index of central sensitization. RESULTS: Compared to placebo, nicotine increased cold pressor pain tolerance (ηp2 = 0.031), ischemic pain threshold (ηp2 = 0.073) and tolerance (ηp2 = 0.056) but had no effect on temporal summation of pain. Flavor did not affect pain sensitivity. Females reported greater ischemic pain sensitivity (ηp2 = 0.027) and greater reductions in craving (ηp2 = 0.086). CONCLUSIONS: Consistent with research from tobacco smoking, analgesia may be reinforcing and contribute to nicotine dependence among ENDS users. More research on sex differences is warranted.

Awareness of the potential consequences of alcohol consumption in the context of chronic pain and prescription opioid use.

Background: Alcohol and prescription opioid use are highly prevalent among chronic pain populations. One-fifth of individuals prescribed opioids report same-day use of alcohol and opioids. Alcohol use and alcohol/opioid co-use can have deleterious pain management and health outcomes. The extent to which individuals with chronic pain are aware of these deleterious outcomes is considerably understudied.Objectives: To explore individuals' understanding of seven health- and pain-related risks of alcohol/alcohol-opioid use. An exploratory aim was to examine whether greater risk awareness was associated with alcohol/opioid use patterns.Methods: Participants included 261 adults age ≥21(36.4% women) endorsing current alcohol use, chronic musculoskeletal pain, and opioid prescription who completed an online survey via Amazon Mechanical Turk.Results: Distribution of the total number of items for which a participant endorsed awareness was as follows: zero (10.7%), one (5.0%), two (13.0%), three (13.8%), four (13.8%), five (11.5%), six (10.0%), and seven items (22.2%). Awareness of the health consequences of alcohol/alcohol-opioid use was positively associated with opioid misuse behaviors (ß = .525, ΔR2 = .251, p < .001), and higher-risk alcohol consumption (ß = .152, ΔR2 = .021, p = .011).Conclusion: Many adults with chronic pain are unaware of the health consequences of alcohol/alcohol-opioid use. Findings of positive covariation between risk awareness and higher-risk alcohol/opioid use suggest that future interventions among this population should go beyond simple risk education and utilize motivational enhancement to help change decisional balance.

Pain as a causal motivator of alcohol consumption: Associations with gender and race.

Despite accumulating evidence indicating reciprocal interrelations between pain and alcohol consumption, no prior work has examined pain as a proximal antecedent of drinking. The goal of the current study was to test the effects of experimental pain induction on ad-lib alcohol consumption among moderate-to-heavy drinkers without chronic pain (N = 237; 42% female; 37% Black; M = 3.26daily drinks). Participants were randomized to either pain-induction (capsaicin + thermal heat paradigm) or no-pain-control conditions. Experimental pain induction lasted for 15 minutes, during which ad-lib alcohol consumption was assessed using an established taste test paradigm. As hypothesized, results indicated that participants randomized to the pain-induction condition poured and consumed more alcohol and reached a higher peak blood alcohol concentration than those randomized to the no-pain condition (ps < 0.05; ηp² range = 0.018-0.021). Exploratory analyses revealed the effects of pain on alcohol consumption to be most pronounced among participants who self-identified as male or Black (relative to female or White, respectively). These findings indicate that the experience of pain serves as a causal, situational motivator for alcohol consumption, and suggest that current drinkers may be susceptible to escalating their consumption of alcohol in the context of pain. Future research is needed to explicate observed differences in the effects of pain on drinking as a function of gender and race, and to extend this work to individuals with chronic pain and varying levels of alcohol use. Collectively, these findings may help inform the development of integrated treatments to address co-occurring pain and alcohol use. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Family History of Alcohol Use Disorder as a Predictor of Endogenous Pain Modulation Among Moderate to Heavy Drinkers.

Family history of alcohol use disorder (AUD) is frequently endorsed by persons with chronic pain. Although individuals with a family history of AUD have demonstrated enhanced sensitivity to painful stimulation, previous research has not examined endogenous pain modulation in this population. The goal of this study was to test family history of AUD as a predictor of conditioned pain modulation, offset analgesia, and temporal summation among a sample of moderate and heavy drinkers. Adults with no current pain (N = 235; 58.3% male; Mage = 34.3; 91.9% non-Hispanic; 60% white) were evaluated for family history of AUD at baseline and pain modulatory outcomes were assessed via quantitative sensory testing. Participants with a family history of AUD (relative to those without) evinced a pro-nociceptive pain modulation profile in response to experimental pain. Specifically, family history of AUD was associated with deficits in pain-inhibitory processes. Approximately 4% of the variance in endogenous pain modulation was accounted for by family history, and exploratory analyses suggested these effects may be driven by paternal AUD. PERSPECTIVE: The current findings suggest individuals with a family history of AUD demonstrate pain modulatory function that may predispose them to the development of chronic pain. Clinically, these data may inform pain management approaches for individuals with a family history of AUD.

Pain Severity and Alcohol Use Among Daily Tobacco Cigarette Smokers.

BACKGROUND AND OBJECTIVES: Pain is associated with hazardous alcohol use. Drinkers have reported using alcohol for pain-coping, and negative affect may be a key mechanism in pain-induced motivation to drink. However, no previous study has examined pain severity in relation to alcohol consumption, dependence, and alcohol-related consequences. Moreover, no studies have examined pain-alcohol interrelations among tobacco cigarette smokers. These secondary analyses tested the hypotheses that greater past 4-week pain severity would be positively associated with indices of hazardous drinking (ie, quantity/frequency, harmful use, and dependence), and that the current pain intensity would be positively/indirectly associated with the urge to drink via negative affect. METHODS: Participants included 225 daily smokers (43% female; MCPD = 22) who completed the baseline session for a larger experimental study. RESULTS: Every one-point increase in pain severity was associated with a 47% increased likelihood of hazardous drinking, and pain severity was positively associated with quantity/frequency of alcohol consumption, harmful patterns of drinking, and alcohol dependence level (Ps < .05). Pain intensity was indirectly associated with urge to drink via negative affect (P < .05). CONCLUSIONS: These findings provide initial evidence that smokers with greater pain severity may also report hazardous patterns of alcohol use. SCIENTIFIC SIGNIFICANCE: This is the first study to demonstrate that past 4-week pain severity may be one factor that maintains three conceptually distinct patterns of hazardous drinking among smokers. The current results also provide the first evidence that greater pain intensity may be associated with an increased urge to drink alcohol, via negative affect. (Am J Addict 2020;29:134-140).