Usage
- Mesterolone is prescribed primarily for the treatment of male hypogonadism, a condition characterized by insufficient testosterone production. It is also used in cases of male infertility associated with low testosterone and delayed puberty in adolescent boys.
- Pharmacological Classification: Androgen; Anabolic-Androgenic Steroid (AAS).
- Mechanism of Action: Mesterolone is an orally active synthetic androgen that binds to androgen receptors, mimicking the effects of natural testosterone. It promotes the development and maintenance of male secondary sexual characteristics and stimulates spermatogenesis in some cases. Unlike testosterone, it is not significantly metabolized by 5-alpha reductase in the target tissues.
Alternate Names
- International/Regional variations: None explicitly stated.
- Brand Names: Proviron, Provironum
How It Works
- Pharmacodynamics: Mesterolone binds to androgen receptors in target tissues, promoting the development and maintenance of male sexual characteristics. It exerts a weaker anabolic effect compared to other AAS due to inactivation by 3α-hydroxysteroid dehydrogenase (3α-HSD) in skeletal muscle. It does not aromatize to estrogen and exhibits some anti-estrogenic properties by competing with other steroids for aromatase binding.
- Pharmacokinetics:
- Absorption: Rapid and almost complete absorption after oral administration.
- Metabolism: Rapidly metabolized in the liver, primarily to 1α-methylandrosterone and 1α-methyl-5α-androstane-3α, 17β-diol.
- Elimination: Primarily via urine (80% as metabolites) and feces (13% as metabolites).
- Elimination Half-Life: Approximately 12-13 hours.
- Mode of Action: Binds to intracellular androgen receptors, leading to gene transcription and protein synthesis, mediating androgenic effects.
- Receptor Binding/Enzyme Inhibition/Neurotransmitter Modulation: Androgen receptor agonist; weak aromatase inhibitor.
- Elimination Pathways: Primarily hepatic metabolism with renal and fecal excretion of metabolites. Not a substrate for aromatase and is not 17α-alkylated, thus minimizing hepatotoxicity.
Dosage
Standard Dosage
Adults:
- Initial: 25-50 mg two to three times a day (75-150 mg total daily dose) for several months.
- Maintenance: 25 mg two to three times a day (50-75 mg total daily dose).
- Male infertility: 50-100 mg per day for 90 days.
Children:
- Not recommended for use in children.
Special Cases:
- Elderly Patients: Use with caution due to increased risk of prostatic hyperplasia and prostate cancer. Dosage adjustments may be required.
- Patients with Renal Impairment: Use with caution, dosage adjustment may be needed.
- Patients with Hepatic Dysfunction: Generally well-tolerated, but use cautiously and monitor liver function tests.
- Patients with Comorbid Conditions: Use with caution in patients with cardiovascular disease, epilepsy, migraine, and diabetes.
Clinical Use Cases
Mesterolone is not typically indicated for use in acute clinical settings such as intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations. Its use is primarily for chronic androgen deficiency.
Dosage Adjustments
- Adjust dosage based on patient response, tolerance, and clinical efficacy.
- Consider renal and hepatic function when determining the appropriate dosage.
Side Effects
Common Side Effects:
- Acne
- Increased libido
- Mood swings
- Hair loss (scalp)
- Increased body hair growth
- Frequent or prolonged erections
- Oily skin
- Fluid retention
Rare but Serious Side Effects:
- Jaundice
- Liver abnormalities (including tumors)
- Priapism (persistent, painful erection)
- Allergic reactions (hives, swelling)
Long-Term Effects:
- Increased risk of prostate cancer
- Venous thromboembolism (VTE)
Adverse Drug Reactions (ADR):
- Severe stomach pain or tenderness
- Changes in urination or blood in the urine or ejaculate
Contraindications
- Prostate cancer
- Breast cancer (in males)
- Existing or history of liver tumors
- Hypercalcemia
- Hypersensitivity to mesterolone
Drug Interactions
- Anticoagulants (e.g., warfarin): Increased risk of bleeding.
- Antidiabetic medications (e.g., insulin, metformin): Altered blood sugar control.
- Other anabolic steroids: Additive effects on liver and cardiovascular system, increased risk of side effects.
- Corticosteroids (e.g., prednisone)
- Drugs that cause liver toxicity (e.g., paracetamol)
- Immunosuppressants (e.g., cyclosporine): Increased cyclosporine levels.
- Antiepileptics (e.g., phenobarbital, phenytoin): Decreased mesterolone levels.
- Hormones (e.g., thyroxine)
- Neuromuscular blockers: Potential resistance to treatment.
Pregnancy and Breastfeeding
- Pregnancy Safety Category: X. Contraindicated in pregnancy due to the risk of virilization of the female fetus.
- Breastfeeding: Contraindicated during breastfeeding as it may be excreted in breast milk.
Drug Profile Summary
- Mechanism of Action: Androgen receptor agonist.
- Side Effects: Acne, increased libido, mood changes, hair loss, liver dysfunction (rare), priapism (rare).
- Contraindications: Prostate cancer, breast cancer, liver tumors, hypercalcemia.
- Drug Interactions: Anticoagulants, antidiabetics, other anabolic steroids.
- Pregnancy & Breastfeeding: Contraindicated.
- Dosage: Adults: Initially 75-150 mg daily, maintenance 50-75 mg daily. Not for use in children.
- Monitoring Parameters: Liver function tests, lipid profile, prostate examination.
Popular Combinations
- Clomiphene citrate: For the treatment of oligospermia.
Precautions
- General Precautions: Pre-existing cardiovascular disease, epilepsy, migraine, diabetes, renal/hepatic impairment.
- Specific Populations: Contraindicated in women, children, pregnant and breastfeeding women. Use with caution in the elderly.
- Lifestyle Considerations: Limit alcohol consumption.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Mesterolone?
A: Adults: Initial dose is 75-150 mg daily in divided doses for several months; maintenance dose is 50-75 mg daily. Not for use in children.
Q2: What are the primary uses of Mesterolone?
A: Treatment of male hypogonadism and male infertility associated with androgen deficiency.
Q3: What are the common side effects of Mesterolone?
A: Acne, increased libido, mood swings, hair loss, increased body hair growth, frequent or prolonged erections.
Q4: What are the serious side effects of Mesterolone?
A: Liver abnormalities (including tumors), jaundice, priapism, allergic reactions.
Q5: Is Mesterolone safe to use in patients with liver disease?
A: No, mesterolone is contraindicated in patients with existing or prior liver tumors. Use with caution in patients with other liver conditions and monitor liver function.
Q6: Can Mesterolone be used in women?
A: No, mesterolone is contraindicated in women due to the risk of virilization.
Q7: Does Mesterolone interact with other medications?
A: Yes, mesterolone can interact with anticoagulants, antidiabetics, and other anabolic steroids. It may also interact with medications metabolized by the liver. A full medication review is essential before prescribing.
Q8: Is Mesterolone safe to use during pregnancy or breastfeeding?
A: No, Mesterolone is contraindicated in pregnancy and breastfeeding.
Q9: How does Mesterolone affect fertility?
A: Mesterolone can improve sperm count and quality in some men with hypogonadism-related infertility, but it can also inhibit spermatogenesis at higher doses.
Q10: Can Mesterolone be used to enhance muscle growth in healthy individuals?
A: No, Mesterolone is not indicated for enhancing muscular development or physical ability in healthy individuals. Its anabolic effects are weak, and the risks outweigh the potential benefits in this context.
Please note that this information is current as of February 16, 2025, and may be subject to change with further research and clinical experience.
