What laboratory tests are recommended before starting Contrave (naltrexone-bupropion) in a patient with a history of diabetes and cardiovascular disease?

Laboratory Testing Before Starting Contrave

Before initiating Contrave (naltrexone-bupropion) in a patient with diabetes and cardiovascular disease, obtain baseline blood pressure, heart rate, liver function tests, renal function tests (creatinine and eGFR), fasting glucose or HbA1c, and a lipid panel. 1, 2

Essential Baseline Laboratory Tests

Hepatic Function

• Liver function tests (AST, ALT, bilirubin, alkaline phosphatase) are mandatory before starting Contrave, as both naltrexone and bupropion are hepatically metabolized and can cause hepatotoxicity 1, 2
• Contrave is contraindicated in patients with acute hepatitis or hepatic failure 3

Renal Function

• Measure serum creatinine and calculate eGFR to assess kidney function, particularly important in diabetic patients who may have diabetic nephropathy 4
• In patients with diabetes and cardiovascular disease, baseline eGFR helps stratify cardiovascular risk and guides concurrent medication management 4

Glycemic Control Assessment

• Obtain HbA1c or fasting plasma glucose to establish baseline glycemic control in diabetic patients 4, 1
• This is critical because Contrave has been shown to reduce HbA1c by approximately 0.5% more than placebo in diabetic patients, and you'll need baseline values to monitor this benefit 2

Cardiovascular Risk Markers

• Obtain a complete lipid panel (total cholesterol, LDL, HDL, triglycerides) as Contrave improves cardiometabolic markers including triglycerides and HDL cholesterol 1, 2
• In patients with established cardiovascular disease and diabetes, lipid management is a core component of risk reduction, with target LDL <70 mg/dL 4

Cardiovascular Vital Signs

• Measure baseline blood pressure and heart rate as Contrave can increase both parameters 2
• This is particularly important in patients with cardiovascular disease, as studies show greater improvement in systolic blood pressure with placebo compared to naltrexone/bupropion (p < 0.001) 2
• Patients with uncontrolled hypertension should have blood pressure optimized before starting Contrave 4

Additional Screening Considerations in High-Risk Patients

Cardiac Assessment

• While routine cardiac screening is not recommended in asymptomatic diabetic patients, those with typical or atypical cardiac symptoms and abnormal resting ECG should undergo cardiac testing before starting weight loss therapy 4
• In adults with diabetes ≥40 years of age with established cardiovascular disease, measurement of natriuretic peptides (BNP ≥50 pg/mL or NT-proBNP ≥125 pg/mL) can identify stage B heart failure 4

Eating Disorder History Screening

• Explicitly screen for current or prior history of bulimia or anorexia nervosa, as this is an absolute FDA contraindication to all bupropion-containing products including Contrave due to increased seizure risk 3
• This contraindication applies regardless of recovery status 3

Common Pitfalls to Avoid

• Do not start Contrave without checking liver function, as hepatotoxicity can occur and baseline values are needed for comparison 1, 2
• Do not overlook blood pressure monitoring in cardiovascular disease patients, as Contrave can worsen hypertension and increase pulse 2
• Do not assume weight loss medications are safe in all diabetic patients—those with unstable heart failure or hospitalized patients require careful evaluation 4
• Do not forget to assess for eating disorder history, as this is an absolute contraindication that increases seizure risk substantially 3

Monitoring During Treatment

• Recheck blood pressure and heart rate at each visit, particularly during the first 12 weeks of therapy 2
• Repeat liver function tests if clinical signs of hepatotoxicity develop 1
• Monitor HbA1c every 3 months in diabetic patients to assess glycemic response 4
• Reassess lipid panel at 2 months after initiation to evaluate cardiometabolic improvements 4, 1