Chronic obstructive pulmonary disease in the elderly: an update on pharmacological management

Interactions of neuroimmune signaling and glutamate plasticity in addiction

Chronic use of drugs of abuse affects neuroimmune signaling; however, there are still many open questions regarding the interactions between neuroimmune mechanisms and substance use disorders (SUDs). Further, chronic use of drugs of abuse can induce glutamatergic changes in the brain, but the relationship between the glutamate system and neuroimmune signaling in addiction is not well understood. Therefore, the purpose of this review is to bring into focus the role of neuroimmune signaling and its interactions with the glutamate system following chronic drug use, and how this may guide pharmacotherapeutic treatment strategies for SUDs. In this review, we first describe neuroimmune mechanisms that may be linked to aberrant glutamate signaling in addiction. We focus specifically on the nuclear factor-kappa B (NF-κB) pathway, a potentially important neuroimmune mechanism that may be a key player in driving drug-seeking behavior. We highlight the importance of astroglial-microglial crosstalk, and how this interacts with known glutamatergic dysregulations in addiction. Then, we describe the importance of studying non-neuronal cells with unprecedented precision because understanding structure-function relationships in these cells is critical in understanding their role in addiction neurobiology. Here we propose a working model of neuroimmune-glutamate interactions that underlie drug use motivation, which we argue may aid strategies for small molecule drug development to treat substance use disorders. Together, the synthesis of this review shows that interactions between glutamate and neuroimmune signaling may play an important and understudied role in addiction processes and may be critical in developing more efficacious pharmacotherapies to treat SUDs.

Adherence and healthcare utilization among older adults with COPD and depression

BACKGROUND AND OBJECTIVE

Adherence to chronic obstructive pulmonary disease (COPD) maintenance medications and antidepressants may reduce healthcare utilization among multimorbid individuals with COPD and depression. We quantified the independent effects of adherence to antidepressants and COPD maintenance medications on healthcare utilization among individuals co-diagnosed with COPD and depression.

PROCEDURES

We conducted a retrospective cohort study using a 2006-2012 5% random sample of Medicare beneficiaries co-diagnosed with COPD and depression who had two or more prescription fills of both COPD maintenance medications and antidepressants. We measured adherence to medications using the proportion of days covered per 30-day period. The primary outcomes were all-cause emergency department (ED) visits and hospitalizations. Beneficiaries were followed over a minimum 12-month follow-up period.

RESULTS

Of the 16,075 beneficiaries meeting inclusion criteria, 21% achieved adherence ≥80% to COPD maintenance medications and 55% achieved adherence ≥80% to antidepressants. Compared to no use and controlling for antidepressant adherence and potential confounders, higher (≥80%) levels of adherence to COPD maintenance medications were associated with decreased risk of ED visits (hazard ratio (HR) 0.79; 95% CI 0.74, 0.83) and hospitalizations (HR 0.82; 95% CI 0.78, 0.87). Similarly, higher levels (≥80%) of adherence to antidepressants resulted in decreased risk of ED visits (HR 0.74; 95% CI 0.70, 0.78) and hospitalizations (HR 0.77; 95% CI 0.73, 0.81) compared to no use.

CONCLUSIONS

Clinicians can assist in the improved management of their multimorbid patients' health by treating depression among patients with COPD and monitoring and encouraging adherence to the regimens they prescribe.

Chronic administration of the methylxanthine propentofylline impairs reinstatement to cocaine by a GLT-1-dependent mechanism

In recent years, interactions between neurons and glia have been evaluated as mediators of neuropsychiatric diseases, including drug addiction. In particular, compounds that increase expression of the astroglial glutamate transporter GLT-1 (N-acetylcysteine and ceftriaxone) can decrease measures of drug seeking. However, it is unknown whether the compounds that influence broad measures of glial physiology can influence behavioral measures of drug relapse, nor is it clear whether the upregulated GLT-1 is functionally important for suppressing of drug seeking. To address these questions, we sought to determine whether the glial modulator and neuroprotective agent propentofylline (PPF) modifies drug seeking in rats using a reinstatement model of cocaine relapse. We found that 7 days of chronic (but not acute) administration of PPF significantly decreased both cue- and cocaine-induced reinstatement of cocaine seeking. We next determined whether the effect of systemic PPF on reinstatement depended upon its ability to restore expression of GLT-1 in the nucleus accumbens. PPF restored the cocaine-induced decrease in GLT-1 in the accumbens core; then, using an antisense strategy against glutamate transporter GLT-1, we found that restored transporter expression was necessary for PPF to inhibit cue-primed cocaine seeking. These findings indicate that modulating glial physiology with atypical xanthine derivatives like PPF is a potential avenue for developing new medications for cocaine abuse, and support the hypothesis that neuron-glial interactions contribute to mechanisms of psychostimulant addiction, particularly via expression and function of astroglial glutamate transporters.

The diagnosis and treatment of elderly patients with acute exacerbation of chronic obstructive pulmonary disease and chronic bronchitis

The syndrome of chronic obstructive pulmonary disease (COPD) consists of chronic bronchitis (CB), bronchiectasis, emphysema, and reversible airway disease that combine uniquely in an individual patient. Older patients are at risk for COPD and its components—emphysema, CB, and bronchiectasis. Bacterial and viral infections play a role in acute exacerbations of COPD (AECOPD) and in acute exacerbations of CB (AECB) without features of COPD. Older patients are at risk for resistant bacterial organisms during their episodes of AECOPD and AECB. Organisms include the more‐common bacteria implicated in AECOPD/AECB such as Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pneumoniae. Less‐common nonenteric, gram‐negative organisms including Pseudomonas aeruginosa, gram‐positive organisms including Staphylococcus aureus, and strains of nontuberculosis Mycobacteria are more often seen in AECOPD/AECB episodes involving elderly patients with frequent episodes of CB or those with bronchiectasis. Risk‐stratified antibiotic treatment guidelines appear useful for purulent episodes of AECOPD and episodes of AECB. These guidelines have not been prospectively validated for the general population and especially not for the elderly population. Using a risk‐stratification approach for elderly patients, first‐line antibiotics (e.g., amoxicillin, ampicillin, pivampicillin, trimethoprim/sulfamethoxazole, and doxycycline), with a more‐limited spectrum of antibacterial coverage, are used in patients who are likely to have a low probability of resistant organisms during AECOPD/AECB. Second‐line antibiotics (e.g., amoxicillin/clavulanic acid, second‐ or third‐generation cephalosporins, and respiratory fluoroquinolones) with a broader spectrum of coverage are reserved for patients with significant risk factors for resistant organisms and those who have failed initial antibiotic treatment.