What medical evaluations and laboratory tests are required before starting tirzepatide treatment?

Pre-Treatment Workup for Tirzepatide

Before initiating tirzepatide, obtain fasting blood glucose (or HbA1c), lipid profile, comprehensive metabolic panel including liver function tests, complete blood count, body mass index, waist circumference, blood pressure, and pregnancy test in women of childbearing potential. 1

Required Baseline Laboratory Tests

Metabolic Parameters

• Fasting blood glucose or HbA1c to assess baseline glycemic status and diabetes risk, as tirzepatide is indicated for type 2 diabetes management 1
• Lipid profile (total cholesterol, LDL, HDL, triglycerides) to establish baseline values before treatment, as GLP-1/GIP receptor agonists can affect lipid metabolism 1
• Comprehensive metabolic panel including liver function tests (ALT, AST, alkaline phosphatase, bilirubin), blood urea nitrogen, serum creatinine, and electrolytes (sodium, potassium, calcium, magnesium) 1

Physical Measurements

• Body mass index (BMI) and waist circumference must be documented at baseline, as weight loss is a primary therapeutic effect of tirzepatide 1
• Blood pressure measurement to establish baseline cardiovascular parameters 1

Additional Testing

• Complete blood count (CBC) to evaluate baseline hematologic parameters 1
• Pregnancy test is mandatory for women of childbearing potential before initiating therapy 1

Critical Contraindications to Screen For

Absolute Contraindications

• Personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2 (MEN 2), as tirzepatide carries this black box warning 1
• History of pancreatitis should be carefully evaluated, as GLP-1/GIP receptor agonists may increase pancreatitis risk 1

Relative Contraindications Requiring Caution

• Severe gastrointestinal disease or gastroparesis, given the high incidence of gastrointestinal adverse events (nausea 10-31%, diarrhea 7-23%, vomiting 2-12%) 1, 2
• Concurrent insulin or sulfonylurea use requires dose adjustment and close monitoring for hypoglycemia 1

Monitoring Schedule After Initiation

Initial 3-Month Period

• BMI measurement monthly during the first 3 months to detect early weight changes 1
• Blood pressure at each visit during initial treatment phase 1

Ongoing Monitoring

• BMI quarterly after the initial 3-month period 1
• Blood pressure, fasting glucose, and lipids should be reassessed at 3 months, then yearly thereafter 1
• Signs and symptoms of pancreatitis or gallbladder disorders should be monitored throughout treatment 1

Common Pitfalls to Avoid

• Failure to obtain baseline values makes it impossible to determine whether metabolic abnormalities are treatment-emergent or pre-existing 1
• Inadequate frequency of weight monitoring in the first 3 months when metabolic changes are most pronounced 1
• Not screening for pregnancy in women of childbearing potential before initiation 1
• Insufficient hydration counseling for patients taking insulin or sulfonylureas, who are at higher risk for hypoglycemia when combined with tirzepatide 1
• Overlooking family history of medullary thyroid carcinoma, which is an absolute contraindication 1

Special Considerations

Patients with Hepatic Steatosis

While tirzepatide reduces hepatic steatosis, patients with pre-existing liver disease should have transaminase levels consistently within normal range before treatment, with at least 3 measurements obtained in the 6 months before treatment to capture fluctuating enzyme levels 1

Dose Escalation Protocol

All patients should start at 2.5 mg subcutaneously weekly, with doses escalated by 2.5 mg every 4 weeks until the target dose (5 mg, 10 mg, or 15 mg) is reached 2