The novel combination of theophylline and bambuterol as a potential treatment of hypoxemia in humans

Hypoxemia can be life-threatening, both acutely and chronically. Because hypoxemia causes vascular dysregulation that further restricts oxygen availability to tissue, it can be pharmacologically addressed. We hypothesized that theophylline can be safely combined with the β2-adrenergic vasodilator bambuterol to improve oxygen availability in hypoxemic patients. Ergogenicity and hemodynamic effects of bambuterol and theophylline were measured in rats under hypobaric and normobaric hypoxia (12% O₂). Feasibility in humans was assessed using randomized, double-blind testing of the influence of combined slow-release theophylline (300 mg) and bambuterol (20 mg) on adverse events (AEs), plasma K⁺, pulse, blood pressure, and drug interaction. Both drugs and their combination significantly improved hypoxic endurance in rats. In humans, common AEs were low K⁺ (<3.5 mmol/L; bambuterol: 12, theophylline: 4, combination: 13 episodes) and tremors (10, 0, 14 episodes). No exacerbation or serious AE occurred when drugs were combined. A drop in plasma K⁺ coincided with peak bambuterol plasma concentrations. Bambuterol increased heart rate by approximately 13 bpm. Drug interaction was present but small. We report promise, feasibility, and relative safety of combined theophylline and bambuterol as a treatment of hypoxemia in humans. Cardiac safety and blood K⁺ will be important safety endpoints when testing these drugs in hypoxemic subjects.

Statin Use and the Risk for Incident Diabetes Mellitus in Patients with Acute Coronary Syndrome after Percutaneous Coronary Intervention: A Population-Based Retrospective Cohort Study in Taiwan

OBJECTIVES

The purpose of this study was to examine the association between statin use by individuals and the risk for incident diabetes mellitus in patients with acute coronary syndrome (ACS) following percutaneous coronary intervention (PCI).

METHODS

We conducted a retrospective cohort study of patients who were hospitalized for ACS between January 1, 2006, and December 31, 2010, and who had undergone PCI (n=30,665); the data were retrieved from the Taiwan National Health Insurance Research Database. A propensity score technique was used to establish a 1:1 matched cohort for statin users and non-statin users (n=9043 for each group). The risk for incident diabetes mellitus in statin users compared to non-statin users for patients with ACS after PCI was estimated by the multivariable Cox proportional hazards regression model.

RESULTS

Statin use was associated with a significant increase of 27% in the risk for new-onset diabetes mellitus (adjusted hazard ratio [HR] 1.27, 95% CI 1.14 to 1.41) compared to non-statin use in the matched cohort. The matched cohort analysis indicated that almost all individual statins were associated with a statistically significant increase in the risk for new-onset diabetes mellitus compared to those without statin use.

CONCLUSIONS

Our study indicated an association between increased risk for new-onset diabetes mellitus and statin use. Because the benefits of statins in prevention of morbidity and mortality in patients with ACS are well-established, clinical decision making should not be changed for patients with existing cardiovascular disease in whom statin therapy is recommended.