What are the recommendations for continuing 100 mg of testosterone cypionate weekly and managing potential side effects?

Testosterone Cypionate 100 mg Weekly: Continuation and Side Effect Management

Continue the 100 mg weekly intramuscular testosterone cypionate regimen, as this dose falls within the standard replacement range (50-200 mg every 2 weeks or 50 mg weekly), but implement rigorous monitoring for erythrocytosis, prostate changes, and cardiovascular risk factors. 1, 2

Dosing Appropriateness

• The 100 mg weekly dose is FDA-approved and guideline-supported for testosterone replacement in hypogonadal males, falling within the typical range of 50-400 mg administered every 2-4 weeks, or 50 mg weekly for more stable levels 2, 1
• Weekly dosing provides more stable testosterone levels compared to bi-weekly administration, reducing the peaks and troughs that contribute to side effects 1

Critical Monitoring Requirements

Testosterone Level Monitoring

• Measure testosterone levels 2-3 months after treatment initiation and after any dose change 1
• For weekly injections, measure testosterone midway between injections (3-4 days post-injection), targeting mid-normal values of 500-600 ng/dL 1
• Once stable levels are confirmed, monitor every 6-12 months 1

Hematocrit/Hemoglobin Surveillance (HIGHEST PRIORITY)

• Erythrocytosis is the most common significant side effect, occurring in 43.8% of patients receiving intramuscular testosterone injections 1
• Monitor hematocrit or hemoglobin at baseline, 3 months, and then every 6-12 months 1
• If hematocrit rises above 52% or hemoglobin becomes elevated, implement dose reduction, withhold testosterone temporarily, or consider therapeutic phlebotomy/blood donation 1
• Intramuscular injections carry significantly higher erythrocytosis risk than transdermal preparations (43.8% vs 15.4%) 1
• Elderly patients and those with chronic obstructive pulmonary disease face greater risk from elevated hematocrit due to increased blood viscosity potentially aggravating coronary, cerebrovascular, or peripheral vascular disease 1

Prostate Monitoring

• Perform digital rectal examination and PSA measurement at baseline, 3 months, 6 months, and then annually 1
• Perform prostate biopsy or refer to urology if:
  • PSA rises above 4.0 ng/mL 1
  • PSA increases by ≥1.0 ng/mL in any 12-month period 1
  • PSA increases by 0.7-0.9 ng/mL in one year (repeat PSA in 3-6 months and biopsy if further increase) 1
• Prostate volume may increase during the first 6 months of therapy, but voiding symptoms typically do not worsen 1

Cardiovascular Considerations

• The FDA issued a 2015 labeling change warning of possible increased risk of heart attack and stroke with testosterone therapy 1
• Some evidence suggests intramuscular injections carry greater cardiovascular risk than gels, potentially related to supraphysiologic and subtherapeutic fluctuations between injections 1
• However, physiologic testosterone replacement at appropriate doses shows neutral effects on lipid profiles (no significant changes in HDL, LDL, or total cholesterol at replacement doses) 1
• Only supraphysiologic doses (≥600 mg weekly) significantly reduce HDL cholesterol 1

Common Side Effects to Monitor

Frequent but Less Serious

• Testicular atrophy and infertility are common due to gonadotropin suppression; counsel patients accordingly 1
• Gynecomastia and breast tenderness may occur in a small percentage of patients 1
• Local injection site reactions including pain, soreness, bruising, erythema, swelling, nodules, or furuncles 1
• Acne and skin reactions 1
• Mild fluid retention (uncommon and generally mild) 1

Sleep Apnea Risk

• Testosterone may exacerbate or precipitate sleep apnea, particularly in men with other risk factors receiving higher parenteral doses 1
• Screen for sleep apnea symptoms, especially in obese patients or those with existing risk factors 1

Advantages of Current Regimen

• Intramuscular testosterone cypionate is relatively inexpensive compared to transdermal preparations 1
• Weekly dosing provides more stable levels than bi-weekly administration, potentially reducing side effect burden 1
• No risk of transference to partners or children (unlike gels) 1
• Flexible dosing schedule allows for self-administration in thighs or gluteal administration by another person 1

Key Pitfalls to Avoid

• Do not ignore rising hematocrit values even if asymptomatic—elevated blood viscosity poses serious cardiovascular risks, particularly in elderly patients 1
• Do not assume prostate safety—while testosterone doesn't cause prostate cancer, it may unmask occult disease; vigilant PSA monitoring is essential 1
• Do not measure testosterone levels at random times—for weekly injections, measure midway between doses for accurate assessment 1
• Do not continue therapy without monitoring—initial 3-month follow-up is critical to detect early complications 1