Cigarette smoking (CS) can impact the immune system and induce pulmonary disorders such as chronic obstructive pulmonary disease (COPD), which is currently the fourth leading cause of chronic morbidity and mortality worldwide. Accordingly, the most significant risk factor associated with COPD is exposure to cigarette smoke. The purpose of the present study is to provide an updated overview of the literature regarding the effect of CS on the immune system and lungs, the mechanism of CS-induced COPD and oxidative stress, as well as the available and potential treatment options for CS-induced COPD. An extensive literature search was conducted on the PubMed/Medline databases to review current COPD treatment research, available in the English language, dating from 1976 to 2014. Studies have investigated the mechanism by which CS elicits detrimental effects on the immune system and pulmonary function through the use of human and animal subjects. A strong relationship among continued tobacco use, oxidative stress, and exacerbation of COPD symptoms is frequently observed in COPD subjects. In addition, therapeutic approaches emphasizing smoking cessation have been developed, incorporating counseling and nicotine replacement therapy. However, the inability to reverse COPD progression establishes the need for improved preventative and therapeutic strategies, such as a combination of intensive smoking cessation treatment and pharmaceutical therapy, focusing on immune homeostasis and redox balance. CS initiates a complex interplay between oxidative stress and the immune response in COPD. Therefore, multiple approaches such as smoking cessation, counseling, and pharmaceutical therapies targeting inflammation and oxidative stress are recommended for COPD treatment.
Background
Despite frequent benzodiazepine use in anxiety disorders, the trajectory and magnitude of benzodiazepine response and the effects of benzodiazepine potency, lipophilicity, and dose on improvement are unknown.
Methods
We performed a meta-analysis using weekly symptom severity data from randomized, parallel group, placebo-controlled trials of benzodiazepines in adults with anxiety disorders. Response was modeled for the standardized change in continuous measures of anxiety using a Bayesian hierarchical model. Change in anxiety was evaluated as a function of medication, disorder, time, potency, lipophilicity, and standardized dose and compared among benzodiazepines.
Results
Data from 65 trials (73 arms, 7 medications, 7110 patients) were included. In the logarithmic model of response, treatment effects emerged within 1 week of beginning treatment (standardized benzodiazepine-placebo difference = −0.235 ± 0.024, CrI: −0.283 to −0.186, P < .001) and placebo response plateaued at week 4. Doses <6 mg per day (lorazepam equivalents) produced faster and larger improvement than higher doses (P = .039 for low vs medium dose and P = .005 for high vs medium dose) and less lipophilic benzodiazepines (beta = 0.028 ± 0.013, P = .030) produced a greater response over time. Relative to the reference benzodiazepine (lorazepam), clonazepam (beta = −0.217 ± 0.95, P = .021) had a greater trajectory/magnitude of response (other specific benzodiazepines did not statistically differ from lorazepam).
Conclusions
In adults with anxiety disorders, benzodiazepine-related improvement emerges early, and the trajectory and magnitude of improvement is related to dose and lipophilicity. Lower doses and less lipophilic benzodiazepines produce greater improvement.
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