Cardiorespiratory function in stable methadone maintenance treatment (MMT) patients

Abstract

Patients in methadone maintenance programmes (MMT) often smoke tobacco and cannabis and many have ongoing illicit drug use. There is therefore potential for these patients to have abnormal cardiorespiratory function; however, few studies address this in stable MMT patients. We assessed resting cardiorespiratory function on 50 stable MMT patients (25 males, 25 females). Forty-six MMT patients were current tobacco smokers, 19 were current cannabis users and none were currently using opioids other than prescribed methadone. We defined abnormalities of respiratory function as those results outside the 95% confidence interval of reference values for normal subjects adjusted for age, weight, height and sex. Thirty-one (62%) MMT patients had reduced carbon monoxide transfer factor (D(L)CO); 17 (34%) had elevated single breath alveolar volume (V(A)) and 43 (86%) had a reduced D(L)CO/V(A) ratio. Six patients (12%) had reduced FEV1; one (2%) had reduced FVC; and nine (18%) had an obstructive ventilatory defect. Ten (20%) patients had PaCO2 higher than 45 mmHg and 14 (28%) had alveolar to arterial oxygen gradient (A-aPO2) higher than 15 mmHg. CXR, Echocardiography and ECG showed no significant abnormalities. We conclude that stable MMT patients have abnormalities of resting respiratory function which may be due to ongoing tobacco cigarette and current or past cannabis smoking.

Prescription medication exchange patterns among methadone maintenance patients

“…Second, this sample was recruited as part of a smoking cessation study. Although nearly 90% of MMT patients smoke (Best et al, 1998; Clarke et al, 2001; Demarie et al, 2011; Teichtahl et al, 2004), it is possible our results would not generalize to non-smokers, or to opioid dependent persons not receiving methadone. Third, the response categories that were used to capture sources of received medication were not mutually exclusive.…”

Tropine exacerbates the ventilatory depressant actions of fentanyl in freely-moving rats

“…As such, it appears that all of these effects of fentanyl were a result of intrinsic mechanisms of action, rather than being caused indirectly by fentanyl-induced behaviors. Several structurally different opioid analgesics, such as fentanyl, morphine oxymorphone, butorphanol, buprenorphine, and methadone, elevate A-a gradients in rats ( May et al, 2013a ; b ; Henderson et al, 2014 ; Getsy et al, 2022a ; b , c ; d ; e ; f ; g ), goats ( Meyer et al, 2006 ), dogs ( Jacobson et al, 1994 ), rabbits ( Shafford and Schadt, 2008 ), impala ( Meyer et al, 2010 ), and humans ( Goetz et al, 1994 ; Teichtahl et al, 2004 ; Wang et al, 2005 ). As was expected, fentanyl elevated the A-a gradient by direct mechanisms involving impairment of alveolar gas exchange or by indirect mechanisms, such as atelectasis ( Henderson et al, 2014 ; Jenkins et al, 2021 ; Seckler et al, 2022 ; Getsy et al, 2022a ; b ).…”

Minimum recommended physical activity, and perceived barriers and benefits of exercise in methadone maintained persons

“…Compared to the general population, persons receiving methadone maintenance treatment (MMT) are at increased risk for diabetes mellitus, hypertension, coronary artery disease, chronic pain, sleep complaints, and other health related co-morbidities (Cullen, O’Brien, O’Carroll, O’Kelly, & Bury, 2009; Fareed, Casarella, Amar, Vayalapalli, & Drexler, 2009; Mertens, Lu, Parthasarathy, Moore, & Weisner, 2003; Sharkey, et al, 2011; Stein, et al, 2004): and they perceive their health to be worse than the general population (Millson, et al, 2004). In addition, nearly 90% of MMT participants smoke cigarettes, heightening their cardiovascular risk (Best, et al, 1998; Clarke, Stein, McGarry, & Gogineni, 2001; Demarie, et al, 2011; Teichtahl, et al, 2004). Psychiatric comorbidity, specifically anxiety and depression, occurs at higher rates in drug dependent individuals (Kandel, Huang, & Davies, 2001).…”