Chapter 41: Drugs Affecting the Male Reproductive System

Androgens, with testosterone as the primary prototype, are male sex hormones responsible for the development of male sexual and secondary characteristics. Clinically, these agents are used as replacement therapy for conditions like hypogonadism and to treat specific breast cancers in women. Androgenic actions promote protein anabolism, increase red blood cell production, and influence electrolyte retention (nitrogen, sodium, potassium, phosphorus). However, their use carries serious risks, including the potential for hepatocellular carcinoma, aggregation of cardiovascular issues, and venous embolic events (DVT and PE). Careful monitoring, including regular liver function tests, is essential, particularly for older adults who may experience exacerbated hypertension or benign prostatic hypertrophy. Anabolic steroids, such as oxandrolone, are testosterone analogues developed to possess stronger tissue-building (anabolic) properties with reduced androgenic effects. These drugs are medically prescribed to reverse catabolic processes, aid weight gain following severe illness or trauma, and treat certain anemias. Despite legitimate uses, anabolic steroids are Class III controlled substances often abused by athletes seeking enhanced performance, a practice associated with grave, potentially fatal adverse effects like liver toxicity, cardiomyopathy, and permanent hormonal changes such as virilization in females or testicular atrophy and priapism in males. Treatment for PED involves either the injected prostaglandin alprostadil, which acts locally to relax smooth muscle, or the oral phosphodiesterase type 5 (PDE5) receptor inhibitors (sildenafil, tadalafil, avanafil, vardenafil). PDE5 inhibitors increase nitrous oxide levels, which activates cyclic guanosine monophosphate (cGMP) to relax vascular smooth muscle, facilitating blood flow into the corpus cavernosum necessary for erection upon sexual stimulation. Notably, sildenafil and tadalafil are also approved to treat pulmonary arterial hypertension (PAH) in both male and female patients. A critical patient safety consideration for PDE5 inhibitors is the absolute contraindication against use with any organic nitrates or alpha-adrenergic blockers, as this combination can precipitate a life-threatening drop in blood pressure and death. Nursing considerations across all drug classes emphasize thorough patient teaching on self-administration, monitoring for adverse effects like virilization or fluid retention, and understanding crucial drug–drug or drug–food interactions, such as avoiding grapefruit juice with PDE5 inhibitors.