From the Guidelines
For a 55-year-old male with dyslipidemia on rosuvastatin and Zepbound (tirzepatide) for weight loss, I recommend monitoring with comprehensive metabolic panel (CMP), lipid panel, hemoglobin A1c, and thyroid stimulating hormone (TSH) every 3-6 months. The CMP will assess liver function (particularly ALT and AST) to monitor for statin-related hepatotoxicity and kidney function (creatinine, BUN) which can be affected by weight loss medications, as suggested by the 2016 ESC/EAS guidelines for the management of dyslipidaemias 1. The lipid panel (total cholesterol, LDL, HDL, triglycerides) is essential to evaluate the effectiveness of rosuvastatin therapy, in line with the recommendations from the 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of blood cholesterol 2, 3. Hemoglobin A1c should be monitored as tirzepatide affects glucose metabolism, even in non-diabetic patients. TSH monitoring is important as significant weight loss can affect thyroid function. Additionally, check creatine kinase (CK) if the patient reports muscle pain to rule out statin-induced myopathy, following the guidelines for monitoring CK levels in patients on lipid-lowering drugs 1. After initial stabilization, these labs can be spaced to every 6 months if values remain stable, but more frequent monitoring may be needed if medication doses are adjusted or if abnormalities are detected. Key points to consider include:
- Monitoring liver enzymes (ALT) before treatment, 8-12 weeks after starting a drug treatment or after dose increase, and as needed thereafter 1
- Checking CK levels before starting therapy and if baseline CK is 4x ULN, not starting drug therapy and rechecking 1
- Being alert regarding myopathy and CK elevation in patients at risk, such as elderly patients, those on concomitant interfering therapy, multiple medications, liver or renal disease, or sport athletes 1
From the Research
Monitoring Labs for Rosuvastatin and Zepbound
To monitor a 55-year-old male with dyslipidemia taking rosuvastatin and zepbound for weight loss, the following labs should be ordered regularly:
- Lipid profile: + Total cholesterol + Low-density lipoprotein cholesterol (LDL-C) + High-density lipoprotein cholesterol (HDL-C) + Triglycerides
- Liver function tests: + Alanine transaminase (ALT) + Aspartate transaminase (AST)
- Kidney function tests: + Creatinine + Urea
- Muscle enzymes: + Creatine phosphokinase (CPK)
- Other tests: + Fasting glucose + Hemoglobin A1c (HbA1c)
Rationale for Lab Monitoring
The rationale for monitoring these labs is based on the potential side effects of rosuvastatin and zepbound. Rosuvastatin can cause liver damage, muscle pain, and kidney problems 4, 5, 6, 7, 8. Zepbound, a weight loss medication, may also have potential side effects that need to be monitored. Regular lab tests can help identify any potential issues early on and allow for adjustments to the treatment plan as needed.
Frequency of Lab Monitoring
The frequency of lab monitoring may vary depending on the individual patient's needs and medical history. However, as a general guideline, the following schedule can be followed:
- Lipid profile: every 6-12 weeks
- Liver function tests: every 6-12 weeks
- Kidney function tests: every 6-12 weeks
- Muscle enzymes: every 6-12 weeks
- Other tests: as needed
It is essential to note that the specific lab tests and frequency of monitoring may vary depending on the patient's individual needs and medical history. Consultation with a healthcare professional is necessary to determine the best course of action for each patient 4, 5, 6, 7, 8.