What lab work is recommended to monitor someone on testosterone therapy and its complications?

Laboratory Monitoring for Testosterone Therapy

Patients on testosterone therapy should be monitored with baseline and follow-up laboratory tests including testosterone levels, PSA, hematocrit/hemoglobin, and lipid profile to prevent serious complications related to therapy. 1, 2

Baseline Testing (Before Starting Therapy)

• Total testosterone levels: Confirms diagnosis and establishes baseline
• PSA (Prostate-Specific Antigen): Establishes baseline prostate health
• Hematocrit or hemoglobin: Screens for polycythemia risk
• Digital rectal examination: Assesses prostate health
• Voiding symptoms assessment: Using standardized questionnaire (e.g., International Prostatic Symptoms Score)
• Sleep apnea history: Document any pre-existing sleep-disordered breathing

Additional recommended baseline tests:

• Lipid profile: Assesses cardiovascular risk
• LH and FSH: Determines if hypogonadism is primary or secondary
• Fasting glucose or HbA1c: Screens for diabetes
• SHBG (Sex Hormone-Binding Globulin): Particularly in men with borderline low total testosterone

Monitoring Schedule

Initial Follow-up (1-2 months)

• Assess efficacy and adjust dosage if needed

Regular Monitoring

• First year: Every 3-6 months
• Subsequent years: Annually if stable

Specific Laboratory Parameters to Monitor

1. Testosterone Levels

• Target range: 450-600 ng/dL (mid-normal range)
• Timing:
  • Injectable testosterone: Measure 2-5 days after injection (peak levels)
  • Transdermal preparations: Measure anytime after patient has been on therapy for at least 1 week

2. Prostate Health

• PSA: Monitor every 3-6 months for first year, then annually
• Action thresholds:
  • PSA > 4.0 ng/mL: Consider prostate biopsy
  • PSA increase > 1.0 ng/mL in any year: Perform biopsy
  • PSA increase of 0.7-0.9 ng/mL in one year: Repeat PSA in 3-6 months and perform biopsy if further increase 1

3. Hematologic Parameters

• Hematocrit/Hemoglobin: Monitor every 3-6 months for first year, then annually
• Action threshold: Discontinue therapy if hematocrit exceeds 54% 2
• Polycythemia is one of the most common adverse effects of testosterone therapy

4. Cardiovascular Parameters

• Lipid profile: Monitor annually
• Testosterone therapy may improve lipid profiles in some patients 3

Special Considerations

Liver Function

• Liver function tests: Not routinely required for injectable or transdermal preparations
• Only necessary with oral 17-alpha-alkylated testosterone preparations (which should be avoided due to hepatotoxicity) 1, 4

Sleep Apnea

• Assess for development or exacerbation of sleep apnea symptoms at each visit
• Higher risk in men receiving higher doses of parenteral testosterone who have other risk factors for sleep apnea 1

Additional Side Effects to Monitor

• Gynecomastia: Physical examination at follow-up visits
• Skin reactions: More common with patches (up to 66%) than with gels (5%) 1
• Fertility concerns: Inform patients about potential for decreased fertility

Common Pitfalls in Monitoring

1. Failure to establish proper baseline: Always obtain comprehensive baseline labs before initiating therapy
2. Inconsistent timing of testosterone measurements: Levels can vary significantly based on time since administration, especially with injectable forms
3. Overlooking PSA velocity: The rate of PSA change is often more important than absolute values
4. Ignoring hematocrit elevations: Polycythemia is a common and potentially serious side effect
5. Not discussing fertility implications: Testosterone therapy suppresses spermatogenesis

By following this structured monitoring approach, clinicians can maximize the benefits of testosterone therapy while minimizing potential risks to patients' health.