PRN Medicines Optimization and Nurse Education.

Medicines management is a high-risk and error prone process in healthcare settings, where nurses play an important role to preserve patient safety. In order to create a safe healthcare environment, nurses should recognize challenges that they face in this process, understand factors leading to medication errors, identify errors and systematically address them to prevent their future occurrence. ''Pro re nata'' (PRN, as needed) medicine administration is a relatively neglected area of medicines management in nursing practice, yet has a high potential for medication errors. Currently, the international literature indicates a lack of knowledge of both the competencies required for PRN medicines management and the optimum educational strategies to prepare students for PRN medicines management. To address this deficiency in the literature, the authors have presented a discussion on nurses' roles in medication safety and the significance and purpose of PRN medications, and suggest a model for preparing nursing students in safe PRN medicines management. The discussion takes into account patient participation and nurse competencies required to safeguard PRN medication practice, providing a background for further research on how to improve the safety of PRN medicines management in clinical practice.

Comparison of the Effect of Prostaglandin E(1), Prostacycline and Adenosine on Peripheral Vascular Resistance.

Prostacycline, prostaglandin E(1), and adenosine are highly effective vasodilators. These three drugs are widely used in the treatment of peripheral arterial occlusive disease. The aim of the study was to compare the vasodilatory potency of these substances in the isolated perfused guinea pig hind limb. After equilibration with Tyrode's solution and precontraction with noradrenaline 3µM, prostaglandin E(1) and adenosine were administered at dosages of 0.1, 0.3, and 1µM, whereas prostacycline was administered at a dosage of 0.01, 0.03 and 0.1µM. 0.01µM prostacycline, 0.1 µM prostaglandin E(1), and 0.1µM adenosine were the lowest dosages at which a significant vasodilation could be reached for each substance. The reduction of peripheral vascular resistance at comparable dosages of 0.1µM was 11.0 +/- 2.6% (x +/- SEM, n = 5) for adenosine, 12.0 +/- 1.0% (n = 5) for prostaglandin E(1), but 28.0 +/- 9.3% (n = 5) for prostacycline (p < 0.05 versus adenosine and prostaglandin E(1)). Even at a dosage of 0.01 µM prostacycline, a comparable reduction in peripheral vascular resistance (16.0 +/- 2.8%) could be reached, compared to a ten-fold higher dosage of prostaglandin E(1) and adenosine. At the highest concentration of 1 µM, the vasodilatory effect of adenosine was significantly less expressed, compared to that of prostaglandin E(1) (18.0 +/- 3.4% versus 33.0 +/- 4.7%). In summary, prostacycline, at a ten-fold lower concentration, showed comparable vasodilatory effects to adenosine and prostaglandin E(1). The rank order at the vasodilatory potency is prostacycline > prostaglandin E(1) > adenosine.