Nebido (Testosterone Undecanoate) Dosing and Administration
The recommended dosing regimen for Nebido (testosterone undecanoate) is 1000 mg initially, followed by a second injection after 6 weeks, and subsequent injections every 12 weeks thereafter. 1, 2
Standard Dosing Protocol
- Nebido is administered as a deep intramuscular injection of 1000 mg testosterone undecanoate in 4 ml castor oil 1
- First injection: 1000 mg (4 ml) 1
- Second injection: 1000 mg (4 ml) at 6 weeks after the first injection 1, 3
- Maintenance injections: 1000 mg (4 ml) every 12 weeks 1, 2
Individualized Dosing Considerations
- Injection intervals can be personalized based on testosterone serum levels:
- Target serum testosterone levels should be in the mid- to upper-normal physiological range for optimal clinical response 4, 2
Monitoring Protocol
- Initial follow-up: 1-2 months after starting treatment to assess efficacy and consider dose adjustments 4
- Subsequent monitoring: Every 3-6 months for the first year, then yearly thereafter 4
- Testosterone levels should be measured midway between injections, targeting mid-normal values (500-600 ng/dL) 4, 2
- Once stable levels are confirmed, monitoring can be reduced to every 6-12 months 4, 2
Clinical Advantages of Nebido
- Provides more stable testosterone levels compared to conventional testosterone esters 2, 5
- Significantly reduces the number of injections required (4-5 injections per year vs. 16+ with testosterone enanthate) 1, 5
- Avoids the peaks and valleys in serum testosterone levels associated with short-acting formulations 1, 2
- Mimics physiological testosterone levels without significant supra- or sub-physiological concentrations 1
Safety Considerations
- Monitor for potential adverse effects:
- If hematocrit rises above the reference range, consider temporarily withholding treatment, reducing the dose, or performing phlebotomy 4
- Prostate monitoring is mandatory with regular PSA measurements and digital rectal examinations 4
Clinical Efficacy
- Studies show significant improvements in testosterone levels within 3 months of initiating therapy 3, 6
- Benefits observed include improvements in sexual function, mood, and bone mineral density 3, 6, 7
- Response rates of 58% have been reported for erectile dysfunction in hypogonadal men using testosterone undecanoate alone 1
Common Pitfalls to Avoid
- Failing to administer the second injection at 6 weeks (critical for establishing stable levels) 1, 3
- Not monitoring testosterone levels at appropriate intervals between injections 4
- Overlooking the need for regular prostate monitoring and hematocrit assessment 4
- Continuing the same dosing interval despite suboptimal clinical response or testosterone levels 4, 1
Nebido's long-acting formulation offers significant advantages over traditional testosterone injections by providing more stable hormone levels and requiring fewer injections, which may improve patient adherence and quality of life 1, 5.