BSN Tracker

testosterone

Brand: Androgel, Testim, Axiron, Depo-Testosterone

⚠ BBW Prototype Drug
Drug Class: androgen
Drug Family: hormone
Subclass: natural androgen / anabolic steroid
Organ Systems: endocrinereproductive

Mechanism of Action

Binds androgen receptors in target tissues (reproductive tract, skeletal muscle, bone, CNS, prostate). AR-testosterone complex acts as a transcription factor activating androgen response elements, mediating anabolic (muscle, bone mass) and androgenic (virilization) effects. Partially converted to DHT (dihydrotestosterone) by 5-alpha reductase and to estradiol by aromatase.

androgen receptor (AR)

Indications

  • male hypogonadism (primary or secondary)
  • delayed puberty in males
  • hormone replacement in transgender men
  • female-to-male transition

Contraindications

  • prostate cancer
  • male breast cancer
  • women (relative; specific circumstances with monitoring)
  • serious cardiac, hepatic, or renal disease

Adverse Effects

Common

  • erythrocytosis (elevated hematocrit)
  • acne
  • oily skin
  • sleep apnea exacerbation
  • testicular atrophy
  • infertility

Serious

  • cardiovascular events (polycythemia, thrombosis)
  • prostate cancer stimulation
  • hepatotoxicity (oral 17-alpha-alkylated forms)
  • secondary exposure to topicals (children, women)
  • gynecomastia (from aromatization to estradiol)

Pharmacokinetics (ADME)

Absorption topical (gel): ~10% absorbed; IM depot (cypionate, enanthate): slow absorption from oil depot
Distribution 98% protein bound (SHBG 44%, albumin 54%)
Metabolism hepatic; converts to DHT (5-alpha reductase) and estradiol (aromatase)
Excretion renal (90%) and fecal (6%)
Half-life 10–100 min (endogenous); 8 days (cypionate ester depot)
Onset weeks (clinical effects)
Peak varies by formulation
Duration 1–4 weeks (IM); daily (topical)
Protein Binding 98%
Vd moderate

Drug Interactions

Drug / Agent Mechanism Severity
warfarin testosterone potentiates anticoagulant effect; increased bleeding risk major
insulin testosterone improves insulin sensitivity; hypoglycemia risk in diabetics moderate

Nursing Considerations

  1. Monitor hematocrit at baseline, 3 months, and annually; hold if hematocrit >54% due to thrombosis risk.
  2. Topical gels: educate patient about secondary exposure risk; apply to shoulders/upper arms; wash hands after application; cover with clothing; avoid skin-to-skin contact with women or children.
  3. Monitor PSA (prostate-specific antigen) and DRE annually in men over 40; do not initiate if suspected prostate cancer.
  4. Check LFTs and lipid panel at baseline and periodically; some testosterone formulations cause adverse lipid changes.

Clinical Pearls

  • Testosterone therapy in male hypogonadism causes azoospermia/oligospermia by suppressing intratesticular testosterone production via the HPG axis; men wishing to preserve fertility should use human chorionic gonadotropin (hCG) instead.
  • Oral 17-alpha-alkylated testosterone (methyltestosterone) should be avoided due to significant hepatotoxicity; transdermal, injectable, and buccal forms are preferred.

Safety Profile

Pregnancy contraindicated
Lactation contraindicated
Renal Adjustment Not required
Hepatic Adjustment Required
TDM Not required

Concordance Terms

Cross-referenced clinical concepts — click any term to see all content where it appears.

Androgen Delayed Puberty In Males Female-to-male Transition Hormone Replacement In Transgender Men Male Hypogonadism (primary Or Secondary)
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