Androjet

Approved Indications:

• Male Hypogonadism (Primary and Secondary):
  Testosterone replacement therapy in adult males with congenital or acquired testosterone deficiency confirmed by clinical symptoms and laboratory tests (e.g., low serum testosterone levels).
• Delayed Puberty in Males:
  Used in adolescent males with clearly diagnosed delayed puberty not due to pituitary-hypothalamic pathology.
• Gender-Affirming Hormone Therapy:
  As part of masculinizing hormone therapy in transgender men (female-to-male individuals), to induce and maintain male secondary sex characteristics.
• Advanced Inoperable Breast Cancer (in Women):
  Palliative treatment of androgen-responsive, advanced breast cancer in postmenopausal women when other therapies are not appropriate.

Clinically Accepted Off-label Uses:

• Muscle Wasting (Cachexia):
  Supportive therapy in patients with chronic illness-related muscle loss, such as in HIV/AIDS or chronic kidney disease.
• Osteoporosis (in Males with Hypogonadism):
  Prevention or treatment of low bone mineral density due to chronic testosterone deficiency.
• Anemia (Refractory):
  Occasionally used in anemia unresponsive to conventional treatments, especially in the presence of hypogonadism.

Adults (Male):

• Recommended Dose:
  1000 mg intramuscularly into the gluteal muscle every 10 to 14 weeks, based on clinical response and serum testosterone levels.
• Initiation Protocol:
  First dose: 1000 mg IM.
  Second dose: 1000 mg after 6 weeks.
  Maintenance doses: every 10 to 14 weeks thereafter.

Pediatrics:

• Delayed Puberty (off-label, with caution):
  Low doses such as 50–100 mg intramuscularly every 4 weeks, titrated gradually. Use should be restricted to specialist pediatric endocrinology supervision.

Elderly:

• Start with lower end of dosing range.
• Close monitoring for prostate health, cardiovascular status, and hematocrit is essential.

Renal or Hepatic Impairment:

• No formal dose adjustment guidelines.
• Use with caution; periodic liver and kidney function tests recommended.

Route of Administration:

• Deep intramuscular injection into the gluteal muscle using a long needle.
• Do not administer intravenously or subcutaneously.

Duration of Therapy:

• Long-term, as clinically indicated.
• Regular reassessment of testosterone levels and therapeutic benefits is advised.

Testosterone decanoate is a long-acting esterified form of testosterone. After intramuscular administration, it is gradually hydrolyzed by esterases in the muscle tissue to release free testosterone. The released testosterone binds to intracellular androgen receptors in target tissues, such as muscle, bone, and prostate. The hormone-receptor complex then translocates to the cell nucleus, where it activates specific DNA sequences, leading to the transcription of androgen-responsive genes. This action results in the development and maintenance of male secondary sexual characteristics (e.g., facial hair, voice deepening), increased muscle mass, bone density enhancement, stimulation of erythropoiesis, and modulation of libido and mood. In some tissues, testosterone is converted to dihydrotestosterone (DHT), a more potent androgen, or to estradiol, contributing to its diverse physiological effects.

• Absorption:
  Slowly absorbed from the intramuscular depot. Steady increase in serum testosterone is observed within 24–48 hours post-injection.
• Bioavailability:
  Not applicable for IM depot injections (complete systemic exposure from muscle depot).
• Distribution:
  Testosterone is highly protein-bound (~98%), mainly to sex hormone-binding globulin (SHBG) and albumin.
• Metabolism:
  Hydrolyzed to free testosterone, which is metabolized in the liver by cytochrome P450 enzymes (primarily CYP3A4) to inactive metabolites. Some testosterone is converted to DHT (via 5-alpha-reductase) or estradiol (via aromatase).
• Excretion:
  Excreted predominantly in urine as conjugated glucuronides and sulfates. A minor portion is excreted in feces.
• Half-life:
  Approximately 7 to 10 days, enabling extended dosing intervals of 10 to 14 weeks.
• Onset of Action:
  Noticeable clinical effects usually appear within 2–4 weeks, with hormonal levels stabilizing after 2–3 injections.

• Pregnancy Category:
  Category X – Contraindicated. Testosterone can cause virilization and birth defects in a female fetus. Should not be used during pregnancy.
• Lactation:
  Not recommended. It is unknown whether testosterone decanoate is excreted in human milk. Theoretical risk exists for adverse developmental effects in the breastfed infant.
• General Note:
  Use in women (except for specific cancer indications) is contraindicated.

• Primary Class: Androgen, Anabolic Steroid
• Subclass: Long-acting injectable testosterone ester

• Known hypersensitivity to testosterone or formulation excipients
• Male breast cancer
• Known or suspected prostate cancer
• Women who are pregnant or breastfeeding
• Severe hepatic, cardiac, or renal insufficiency
• Polycythemia (elevated hematocrit >54%)
• Hypercalcemia of malignancy

• Cardiovascular Risks:
  Increased risk of myocardial infarction, stroke, and venous thromboembolism. Caution in patients with cardiovascular disease.
• Prostate Monitoring:
  PSA levels and digital rectal examination recommended before and during therapy to detect prostate hypertrophy or cancer.
• Polycythemia:
  Regular monitoring of hematocrit and hemoglobin levels is essential; dose adjustments may be needed if hematocrit >54%.
• Hepatic Function:
  Periodic liver function tests recommended. Discontinue if liver dysfunction develops.
• Sleep Apnea:
  May worsen or unmask sleep apnea, especially in obese patients or those with pulmonary disease.
• Fertility:
  May suppress spermatogenesis and cause temporary infertility.
• Adolescent Use:
  Risk of premature epiphyseal closure. Use only under specialist supervision.

Common:

• Pain or swelling at injection site
• Acne, seborrhea
• Fluid retention and peripheral edema
• Increased red blood cell count (polycythemia)
• Libido changes
• Mood swings, irritability
• Gynecomastia (rare)

Serious (but less common):

• Prostate hypertrophy or cancer progression
• Hepatic toxicity (elevated liver enzymes, cholestatic jaundice)
• Cardiovascular events (e.g., MI, stroke, thrombosis)
• Sleep apnea exacerbation
• Infertility due to gonadotropin suppression

Onset and Severity:

• Some effects occur within weeks, while others (e.g., prostate changes, erythrocytosis) may take months.
• Severity is often dose-related.

• CYP3A4 inducers (e.g., rifampin, phenytoin): May decrease testosterone levels.
• CYP3A4 inhibitors (e.g., ketoconazole, erythromycin): May increase testosterone levels.
• Oral anticoagulants (e.g., warfarin): May alter INR; close monitoring required.
• Corticosteroids or ACTH: Increases risk of edema and fluid retention.
• Antidiabetics: May enhance the hypoglycemic effect; blood glucose levels may need monitoring.

• Endocrine Society (2024):
  Reaffirmed that testosterone therapy should be initiated only in men with confirmed clinical symptoms and consistently low testosterone levels on two separate morning blood tests.
• Regulatory Alerts (FDA/EMA):
  Ongoing surveillance on cardiovascular and prostate risks. Physicians are advised to monitor closely and prescribe only when clearly indicated.
• New Formulations:
  Long-acting testosterone undecanoate (oral or injectable) being evaluated as alternatives for patient convenience, but testosterone decanoate remains a preferred long-acting IM option in many settings.

• Temperature: Store at 20°C to 25°C (68°F to 77°F).
• Humidity/Light Protection: Protect from excessive moisture and direct light.
• Handling:
• Do not freeze.
• Vial should be inspected visually for particulate matter or discoloration before use.
• Allow the solution to come to room temperature before administration.
• Shelf Life: As per manufacturer’s instructions; generally 2 to 3 years if stored properly.