What is the initial dosage of testosterone (intramuscular injection) for a patient with hypogonadism?

Initial Testosterone Dosage for Hypogonadism Treatment

For male patients with hypogonadism, the initial dosage of testosterone cypionate for intramuscular injection should be 50 to 200 mg every two weeks. 1

Dosing Guidelines for Testosterone Replacement Therapy

The FDA-approved dosing for testosterone cypionate injection provides clear guidance:

• Initial dosage range: 50 to 400 mg every two to four weeks 1
• Typical administration:
  • 50-200 mg every two weeks
  • 300 mg every three weeks 1, 2

Injectable testosterone formulations offer several advantages:

• Relatively inexpensive
• Flexible and infrequent dosing
• Reliable achievement of therapeutic levels 3

Dosing Considerations

When determining the initial dose, several factors should be considered:

1. Patient age and clinical presentation:

   • Younger patients may require higher doses to induce pubertal changes
   • Older patients may respond to lower doses with maintenance therapy 1

2. Target testosterone levels:

   • Aim for middle tertile of normal reference range (450-600 ng/dL) 3
   • Measure levels midway between injections (day 7-10 for biweekly injections) 3

3. Dose-response relationship:

   • 100 mg weekly or 200 mg biweekly regimens effectively normalize testosterone levels 2, 4
   • Higher doses (400 mg monthly) may be less effective at suppressing elevated LH 2

Monitoring Protocol

After initiating testosterone therapy:

• Initial follow-up: 1-2 months after starting therapy 3
• Subsequent monitoring: Every 3-6 months during first year, then yearly once stable 3
• Key parameters to monitor:
  • Testosterone levels (midway between injections)
  • Hematocrit/hemoglobin (risk of erythrocytosis)
  • Cardiovascular risk factors 3

Potential Pitfalls

• Supraphysiologic peaks: Intramuscular testosterone cypionate can cause significant rises in estradiol, hematocrit, and PSA due to supraphysiological testosterone peaks 4
• Fluctuating levels: Injectable testosterone may cause significant fluctuations in serum testosterone levels 3, 5
• Individual variability: Some patients may exhibit abnormally high serum testosterone levels beyond the physiological range 5
• Gonadotropin suppression: Treatment suppresses LH and FSH, which is important to note if fertility is desired 5, 3

Contraindications

Testosterone replacement therapy is contraindicated in patients with:

• Prostate cancer
• Male breast cancer
• Desire for fertility in the near future
• Severe obstructive sleep apnea
• Uncontrolled congestive heart failure
• Hematocrit >54% 3

Alternative Formulations

If intramuscular injections are not preferred:

• Subcutaneous testosterone enanthate (100 mg weekly) may provide similar efficacy with potentially lower estradiol and hematocrit elevations 4
• Transdermal formulations may have less risk of erythrocytosis than injections 3