Usage
- Testosterone Isocaproate is prescribed for the treatment of male hypogonadism, a condition where the body doesn’t produce enough testosterone. It is specifically used as a component of mixed testosterone ester preparations like Sustanon. It is also sometimes used as supportive therapy for female-to-male transsexuals.
- Pharmacological classification: Androgen, Steroid hormone.
- Mechanism of Action: Testosterone Isocaproate is a prodrug of testosterone. After intramuscular injection, the isocaproate ester is cleaved, releasing testosterone into the bloodstream. Testosterone then exerts its effects by binding to androgen receptors in target tissues, influencing gene expression and promoting the development and maintenance of male secondary sexual characteristics.
Alternate Names
- Does not typically have alternate names as it is usually part of combined preparations. The most common of these preparations is Sustanon.
- Brand Names: Sustanon 250.
How It Works
- Pharmacodynamics: Binds to androgen receptors, stimulating protein synthesis, promoting development of male sexual characteristics (muscle mass, bone density, libido), erythropoiesis, and inhibiting luteinizing hormone (LH) secretion.
- Pharmacokinetics:
- Absorption: Administered intramuscularly; the ester is slowly hydrolyzed, providing a sustained release of testosterone.
- Metabolism: Hepatic metabolism to various inactive metabolites.
- Elimination: Primarily renal excretion of metabolites.
- Mode of Action: Binds to intracellular androgen receptors, translocates to the nucleus, and modulates gene transcription.
- Receptor Binding: Androgen receptor agonist.
- Elimination Pathways: Primarily hepatic metabolism followed by renal excretion.
Dosage
Standard Dosage
Adults:
- Typically administered as part of a mixed testosterone ester preparation (e.g., Sustanon 250). Usual dosage is 1 mL (250 mg) intramuscularly every 3 weeks.
- Dose can range between 50 - 400 mg every 2-4 weeks based on serum testosterone levels and clinical response.
Children:
- Not typically indicated for use in children.
Special Cases:
- Elderly Patients – Dosage adjustments may be necessary based on individual response and tolerance.
- Patients with Renal Impairment – Caution is advised, and dose adjustments may be needed. Monitor renal function.
- Patients with Hepatic Dysfunction – Caution is advised, and dose adjustments may be needed. Monitor liver function.
- Patients with Comorbid Conditions – Use with caution in patients with cardiovascular disease, prostate cancer, or breast cancer.
Clinical Use Cases
- Primarily used for treating hypogonadism and not specifically indicated for use in settings like intubation, surgery, mechanical ventilation, or ICU care.
Dosage Adjustments
- Based on patient response, serum testosterone levels, and the presence of comorbidities.
Side Effects
Common Side Effects
- Injection site pain, acne, increased red blood cell count (polycythemia), gynecomastia, prostate enlargement, fluid retention, mood changes.
Rare but Serious Side Effects
- Venous thromboembolism, myocardial infarction, stroke, sleep apnea, hepatic dysfunction.
Long-Term Effects
- Prostate cancer risk, cardiovascular disease risk, infertility.
Adverse Drug Reactions (ADR)
- Severe allergic reactions (rare), priapism.
Contraindications
- Prostate cancer, male breast cancer, known hypersensitivity to testosterone or any component of the formulation.
Drug Interactions
- Anticoagulants (may enhance anticoagulant effects), corticosteroids, diabetes medications.
Pregnancy and Breastfeeding
- Contraindicated in pregnancy (Pregnancy Category X) and breastfeeding.
Drug Profile Summary
- Mechanism of Action: Androgen receptor agonist, promoting development of male sexual characteristics and inhibiting LH secretion.
- Side Effects: Injection site pain, acne, polycythemia, gynecomastia, prostate enlargement, edema, mood swings.
- Contraindications: Prostate cancer, male breast cancer, hypersensitivity.
- Drug Interactions: Anticoagulants, corticosteroids, diabetes medications.
- Pregnancy & Breastfeeding: Contraindicated.
- Dosage: 1 mL IM every 3 weeks (as part of Sustanon 250), individualized based on response.
- Monitoring Parameters: Serum testosterone levels, prostate-specific antigen (PSA), complete blood count (CBC), liver function tests.
Popular Combinations
- Testosterone Isocaproate is itself commonly found as a component in combination preparations like Sustanon 250, often administered without any additional medications for its own use case.
Precautions
- General Precautions: Monitor for signs of virilization, prostate enlargement, cardiovascular events, and liver dysfunction.
- Specific Populations: Contraindicated in pregnant and breastfeeding women. Use with caution in elderly patients and those with hepatic or renal impairment.
- Lifestyle Considerations: Encourage healthy lifestyle modifications (diet, exercise) for overall health.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Testosterone Isocaproate?
A: As a component of Sustanon 250, the usual dosage is 1 mL IM every 3 weeks, adjustable based on clinical response. It can also be found in doses of 50 - 400 mg every 2-4 weeks as part of different testosterone blends.
Q2: How is Testosterone Isocaproate administered?
A: Intramuscular injection only.
Q3: What are the common side effects?
A: Acne, injection site pain, increased red blood cell count, gynecomastia, prostate changes, mood swings, and fluid retention.
Q4: Is Testosterone Isocaproate safe for women?
A: Generally not recommended for women due to virilization risks. Used with extreme caution, if at all, in some female to male transgender individuals.
Q5: Can Testosterone Isocaproate be used in children?
A: Not typically used in children.
Q6: What should be monitored during therapy?
A: Testosterone levels, PSA levels, CBC, and liver function tests.
Q7: What are the signs of an overdose?
A: Priapism, increased frequency or persistence of erections, other androgenic effects.
Q8: Does Testosterone Isocaproate interact with other medications?
A: Yes, it can interact with anticoagulants, corticosteroids, and diabetes medications.
Q9: What are the long term implications if any?
A: May increase the risk of cardiovascular disease, liver dysfunction and prostate issues over time.
