Calcium channel blockers for lung function improvement in asthma: A systematic review and meta-analysis.

BACKGROUND: For decades, calcium channel blockers (CCBs) have been believed to play a role in asthma treatment. However, the clinical efficacy of CCBs for lung function improvement in patients with asthma has not been qualitatively evaluated. OBJECTIVE: To assess the effect of CCBs vs placebo on lung function test results in adults with asthma. METHODS: Various databases were systematically searched to identify all randomized clinical trials with adults with asthma. We aimed to assess the influence of CCBs on forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), peak expiratory flow rate (PEFR), and provocative concentration of bronchoconstrictive agents causing a 20% decrease in FEV1 (PC20) compared with a placebo. All effect estimates were pooled by the generic inverse variance method with random-effects meta-analysis. Subgroup analysis, sensitivity analysis, and heterogeneity investigation were performed. RESULTS: Thirty eligible articles with 301 patients were included in this meta-analysis. Our results revealed that in a standard exercise test CCBs could produce a mean maximal percentage decrease in FEV1 of 11.56% (95% confidence interval, 8.97%-14.16%; P < .001) and an increase in postdose FEV1 by 80 mL (95% confidence interval, 0.02-0.15 mL; P = .01). However, there was no statistical significance for CCBs in postdose FVC, PEFR, or PC20 of histamine and methacholine. CONCLUSION: CCBs may be beneficial for lung function improvement in asthma, especially in exercise-induced asthma. However, there is a lack of evidence for CCBs protecting asthma patients from chemical irritation.

Intermittent Hypoxia Inhibits Hepatic CYP1a2 Expression and Delays Aminophylline Metabolism.

Purpose: In this study, we aimed to determine the effects of intermittent hypoxia (IH) on hepatic cytochrome P450 1A2 (CYP1A2) expression and the pharmacokinetics of CYP1A2-mediated aminophylline and warfarin in vitro and in a rabbit model of obstructive sleep apnea. Materials: Human normal liver (LO-2) cells were exposed to 30 min each of 1%, 1-21%, 21%, and 21-1% O2, and then, CYP1A2 expression and drug concentrations were analyzed. We compared the pharmacokinetic parameters of drugs administered to normoxic rabbits and those exposed to 10 min of IH during which the oxygen level fluctuated from 21% to 8%-10% (n = 10 per group). Result: s. The expression of CYP1A2 protein in vitro was significantly reduced in the IH compared with the normoxic cells (0.56 ± 0.11 vs. 1.27 ± 0.17, p < 0.001). Aminophylline was more abundant in cell culture supernatants after 48 h of IH than in those under normoxia. The T 1/2, AUC0-24 h, and Ke values for aminophylline were significantly higher in the IH group. Conclusion: Intermittent hypoxia inhibits hepatic CYP1A2 expression and delays aminophylline metabolism, suggesting that the impact of IH on the expression of CYP enzymes should be closely monitored in clinical practice.

Atorvastatin attenuates intermittent hypoxia-induced myocardial oxidative stress in a mouse obstructive sleep apnea model.

Chronic intermittent hypoxia (CIH), a hallmark of obstructive sleep apnea (OSA), is associated with various cardiovascular diseases. In the present study, we assessed the effect of the lipid reducing agent atorvastatin on CIH-induced myocardial oxidative stress and apoptosis in a mouse OSA model. Forty-eight C57BL/6J mice were evenly divided among normoxia + vehicle, normoxia + atorvastatin, CIH + vehicle, and CIH + atorvastatin groups. CIH consisted of a hypoxia-reoxygenation cycle in which oxygen concentrations fluctuated from 21% to 6% and back over two minutes for 8 hours each day (30 events/hour). CIH exposure continued for 12 weeks. Atorvastatin (5 mg/kg) was administered from week 6 through the end of the experiment. CIH increased malondialdehyde levels and decreased superoxide dismutase activity, total antioxidant capacity, and nuclear factor erythroid 2-related factor 2 levels in cardiac tissue, indicating a reduction in antioxidant activity. Atorvastatin significantly reversed those effects (p < 0.05). CIH also increased B-cell lymphoma 2-associated protein X and cleaved caspased-3 levels as well as the myocardial apoptotic rate, as indicated by terminal deoxynucleotidyl transferase dUTP nick-end labeling. Atorvastatin had no effect on those changes (p > 0.05). Thus, atorvastatin administration exerts antioxidant but not anti-apoptotic effects after CIH and may therefore have therapeutic potential in OSA patients with cardiovascular comorbidities.

A case report of acute fibrinous and organizing pneumonia with pneumothorax and avian exposure history.

Acute fibrinous and organizing pneumonia (AFOP) is an uncommon variant of acute lung injury. Here, we report a patient with AFOP and a previously unreported condition, pneumothorax. After our experience with this case, we suggest that exposure to birds may be associated with AFOP; pneumothorax can develop in patients with AFOP; and glucocorticoids are very effective for treating AFOP.