What is the proper usage and dosage of Anavar (oxandrolone)?

Oxandrolone (Anavar): Clinical Usage and Dosing

Oxandrolone is FDA-approved for weight restoration after severe trauma, major surgery, chronic infections, and specific conditions including severe burns, hereditary angioedema prophylaxis, and certain neuromuscular disorders, with adult dosing ranging from 2.5-20 mg daily in divided doses and pediatric dosing at ≤0.1 mg/kg/day. 1

FDA-Approved Indications and Standard Dosing

Adult Dosing

• Standard range: 2.5-20 mg daily, divided into 2-4 doses 1
• Therapy should be intermittent with courses of 2-4 weeks, repeated as indicated 1
• Geriatric patients: 5 mg twice daily 1
• The response varies significantly between individuals; some achieve desired effects with as little as 2.5 mg daily while others require up to 20 mg daily 1

Pediatric Dosing

• ≤0.1 mg/kg body weight daily (≤0.045 mg/pound) 1
• Intermittent courses as indicated 1
• Critical caveat: The American Academy of Pediatrics recommends avoiding anabolic steroids including oxandrolone in children before Tanner Stage V puberty due to growth effects 2

Specific Clinical Applications

Hereditary Angioedema (HAE) Prophylaxis

• Adult dosing: 10 mg/day (range 2.5 mg every 3 days to 20 mg/day) 3
• Pediatric dosing: 0.1 mg/kg/day (range 2.5 mg/week to 7.5 mg/day) 3
• Important hierarchy: Oxandrolone is considered second-line therapy for HAE prophylaxis; first-line therapies include subcutaneous C1-INH and lanadelumab 2
• Efficacy is substantial: reduces attack frequency and severity by >90% in most patients when used at adequate doses 2
• Oxandrolone demonstrates superior hepatic safety compared to stanozolol, another anabolic steroid option 2
• Dose should be titrated to the lowest effective level to minimize adverse effects 4

Severe Thermal Injury

• 10 mg orally twice daily has been the most studied regimen 5
• Benefits include improved wound healing, restored lean body mass, and accelerated body weight gain 5
• During rehabilitation, oxandrolone combined with adequate nutrition and exercise improves lean body mass, increases muscle strength, and restores body weight 5
• Treatment duration in burn patients typically extends through the acute recovery period and into rehabilitation 5

Pediatric Burns

• 0.1 mg/kg per day starting at discharge and continuing until 1 year post-burn 6
• Combination with exercise is superior: oxandrolone plus a 12-week exercise program (started 6 months post-burn) produces significantly greater improvements in weight, lean body mass, and muscle strength compared to oxandrolone alone or exercise alone 6

Critical Illness and Post-ICU Recovery

• May be considered as part of multimodal intervention for post-ICU recovery, particularly in patients with persistent testosterone deficiency 7
• In severe burns specifically, oxandrolone reduces weight loss, increases lean mass, improves donor-site healing, and reduces hospital length of stay 7

Essential Monitoring Requirements

All patients on oxandrolone require systematic monitoring 2:

• Liver function tests (transaminases are the most common abnormality) 8
• Lipid panel (particularly HDL cholesterol, which may decrease) 8
• Growth parameters in children (height, bone age) 2
• Hematocrit 2
• Virilization signs in women (voice changes, hirsutism, menstrual irregularities) 2, 7
• Blood pressure and cardiovascular risk factors 2

Critical Safety Considerations

Reproductive Effects

• Women of reproductive age can still ovulate and conceive while taking oxandrolone 7
• Additional contraceptive methods must be used during treatment 7
• In male rats, oxandrolone profoundly suppresses reproductive development, decreasing testicular weight by 69%, prostate weight by 50%, and testicular testosterone production to 1.3% of control values 9

Common Adverse Effects in Women

• Virilization, hirsutism, hoarseness or voice deepening 7
• Weight gain 7
• Menstrual irregularities 7
• Breast hypotrophy 7
• Most effects are dose-related and can be minimized by using the lowest effective dose 7

Hepatic Safety Profile

• Unlike other C17-alpha-alkylated anabolic steroids, oxandrolone's chemical configuration confers resistance to liver metabolism 8
• Does not typically exhibit serious hepatotoxic effects (jaundice, cholestatic hepatitis, peliosis hepatis, neoplasms) seen with other oral anabolic steroids 8
• Most commonly documented effects are transient transaminase elevations and HDL cholesterol reductions 8

Conditions Where Evidence is Insufficient

• Cancer-related muscle wasting: Insufficient consistent clinical data to recommend oxandrolone for increasing muscle mass in cancer patients 7
• In non-small cell lung cancer patients undergoing chemotherapy, anabolic steroids showed only a trend toward smaller body weight loss 7
• Duchenne dystrophy: Not recommended per 2010 guidelines 2
• Sarcopenia: Despite theoretical benefits, oxandrolone has not been adequately studied in age-related muscle loss 8

Key Clinical Pearls

• Oxandrolone is adjunctive therapy, not a replacement for conventional treatment 1
• Therapy should be intermittent rather than continuous 1
• Individual response varies significantly; dose titration based on clinical response and adverse effects is essential 1
• The drug has demonstrated neuroregenerative potential in case reports, with evidence of increased myelin synthesis at peripheral nervous system sites 10
• Optimal risk-benefit ratios require careful patient selection and monitoring 8