Lab Codes for Pre-Treatment Monitoring Before Sertraline and Naltrexone
Order a Comprehensive Metabolic Panel (CMP), Liver Function Tests (LFTs), and thyroid panel (TSH with free T4) before initiating sertraline and naltrexone therapy.
Required Lab Codes
Comprehensive Metabolic Panel (CMP)
- CPT Code: 80053 - This single code covers glucose, calcium, electrolytes (sodium, potassium, chloride, CO2), kidney function (BUN, creatinine), and basic liver markers (albumin, total protein, bilirubin, alkaline phosphatase, AST, ALT) 1
Additional Liver Function Tests (if not adequately covered by CMP)
- CPT Code: 80076 (Hepatic Function Panel) - Provides comprehensive liver assessment including albumin, total and direct bilirubin, ALT, AST, and alkaline phosphatase 1, 2, 3
- Alternatively, individual codes if ordering separately:
Thyroid Panel
Clinical Rationale
Why These Tests Matter
Baseline liver function monitoring is essential because both medications can affect hepatic function, and naltrexone specifically has documented effects on liver enzymes 1, 2, 3. The CMP provides baseline kidney and electrolyte status, which is important for monitoring overall metabolic health during treatment 1.
Thyroid function testing is critical because:
- Thyroid dysfunction can alter liver function test interpretation, making baseline values essential 4
- Naltrexone may influence thyroid hormone levels, particularly T3 and the T4 to T3 conversion ratio over time 5
- Psychiatric symptoms can overlap with thyroid dysfunction, making it important to rule out thyroid disease before attributing symptoms solely to psychiatric conditions 1
Monitoring Schedule After Initiation
Once treatment begins, follow-up monitoring should include 1:
- LFTs: Monthly for the first 3 months, then every 2 months thereafter
- CMP: Every 3-6 months to monitor metabolic parameters
- Thyroid function: Every 3-6 months, or sooner if symptoms develop
Important Caveats
Do not skip the thyroid panel even though it may seem unrelated to the primary indication - thyroid abnormalities can significantly confound both psychiatric symptom assessment and liver function test interpretation 4. The positive correlations between thyroid hormones and liver enzymes mean that undiagnosed thyroid disease could lead to misinterpretation of hepatotoxicity 4.
Naltrexone has documented effects on cytochrome P450 enzymes (particularly CYP2C9, CYP2D6, and CYP3A4), which could affect metabolism of other medications the patient may be taking 6. While this doesn't change the baseline labs needed, it's important for medication reconciliation.