Hyperkalemia is a potentially lethal metabolic disorder characterized by an increase in serum potassium above 5.0 mEq/L (or 5.0 mmol/L). Severe hyperkalemia can trigger fatal arrhythmias by altering cardiac electrophysiology, specifically conduction and repolarization, manifesting as electrocardiographic changes such as QRS widening and a sinusoidal wave pattern. In Mexico, its incidence and prevalence are closely linked to highly prevalent chronic diseases such as chronic kidney disease (CKD) and diabetes mellitus, as these conditions predispose to potassium accumulation in the blood due to decreased renal excretion and the use of medications that interfere with potassium metabolism. While managing this condition is a common challenge in critically ill patients, calcium gluconate administration has traditionally been a key intervention in the acute management of hyperkalemia. However, recent studies suggest that, contrary to the prevailing view that its mechanism of action lies in "membrane stabilization," its primary effect is to restore electrical conduction through the activation of L-type calcium channels and ephaptic coupling. The aim of this article is to provide the reader with context and disseminate these findings in order to highlight their importance in making informed clinical decisions in this clinical scenario.

The article highlights that, despite approximately 50% of pregnancies worldwide being unplanned, modern contraceptive options for men are almost exclusively limited to condoms and vasectomy. The document analyzes the development of hormonal methods, such as dimethandrolone undecanoate (DMAU) and 11β-MNTDC, which aim to suppress sperm production by inhibiting gonadotropic hormones. It also describes promising non-hormonal alternatives, including reversible polymeric barriers such as VasalGel and RISUG, and the disruption of retinoic acid synthesis through enzyme inhibition. The development of new male contraceptives represents a critical advance for public health and equity in reproductive responsibility. Although many of these methods still require further research on their safety and reversibility, their future implementation could significantly transform family planning practices globally. The aim of this work is to review recent advances in the development of male contraceptive methods, exploring both hormonal and non-hormonal options, in order to encourage greater male participation in family planning and reduce the rate of unwanted pregnancies.

The purpose of this article is to introduce the reader to the Active Recall technique as an essential learning strategy for today's medical students, detailing its practical implementation, its benefits for academic performance, and the scientific foundations that support it. Active Recall is defined as a study method that consists of the active retrieval of previously learned information through the use of quizzes, tests, or flashcards, instead of passive memorization. The article explains that this technique forces the brain to make a retrieval effort, which facilitates the identification of gaps in knowledge and fosters a deep and lasting understanding of complex topics. It also highlights the importance of integrating this methodology with spaced repetition to consolidate long-term memory, optimize study time under the principle of "quality hours, not quantity," and prevent student burnout. Implementing Active Recall is a fundamental tool for managing the vast amount of information in medical school. By taking an active role in their academic training, students not only improve their long-term retention of concepts, but also develop critical skills for their future clinical practice.