Nonprescription drugs pose unique challenges to regulators. The fact that the barriers to access are lower for nonprescription drugs as compared with prescription drugs may permit additional consumers to obtain effective drugs. However, the use of these drugs by consumers in the absence of supervision by a health-care professional may result in unacceptable rates of misuse and suboptimal clinical outcomes. A value-tree method is proposed that defines important benefit and risk domains relevant to nonprescription drugs. This value tree can be used to comprehensively identify product-specific attributes in each domain and can also support formal benefit-risk assessment using a variety of tools. This is illustrated here, using a modification of the International Risk Governance Council (IRGC) framework, a flexible tool previously applied in a number of fields, which systematizes an approach to issue review, early alignment of stakeholders, evaluation, and risk mitigation/management. The proposed approach has the potential to provide structured, transparent tools for regulatory decision making for nonprescription drugs.

Using laser fluctuation spectroscopy, a technique that measures particle size change in solution, the kinetics of fibrin clot formation from fibrinogen can be studied. With this technique the effect of calcium on the three distinguishable phases of clot formation, (1) proteolysis of fibrinogen, (2) fibrinogen-fibrin monomer complex formation, and (3) fibrin monomer polymerization, were investigated. Only a small change in the length of the induction period that results from the fibrinogen-fibrin monomer interactions was observed. However, there was a marked increase in the rate of fibrin monomer polymerization in the presence of calcium ions. These data show that calcium decreases the time required for fibrin formation from fibrinogen by markedly accelerating the phase of fibrin monomer polymerization.

Statins are associated with adverse effects in skeletal muscle. This study tested the hypothesis that atorvastatin would increase the respiratory exchange ratio (RER) at rest and during exercise. Twenty-eight healthy subjects (mean age 52 years) were enrolled in a double-blind, placebo-controlled, randomized study of the effects of atorvastatin (40 mg/day) on whole body energetics over 8 weeks. Ventilatory gas exchange measurements, at rest and during bicycle ergometry, were used to assess muscle oxidative metabolism. Thirteen subjects from each treatment arm completed the study. Eight weeks of atorvastatin lowered plasma low-density lipoprotein cholesterol concentration but had no effect on resting or submaximal energy expenditure, RER, or calculated fatty acid oxidation rates. Atorvastatin did not affect maximal exercise oxygen consumption or the anaerobic threshold. Eight weeks of atorvastatin therapy was not associated with alterations in substrate oxidation, or muscle oxidative function at rest, or during exercise in healthy adults.