What evaluations and discussions are necessary before initiating medications like liraglutide (Victoza) or semaglutide (Ozempic) for weight loss?

Pre-Initiation Evaluation and Patient Counseling for GLP-1 Receptor Agonists (Liraglutide/Semaglutide)

Before prescribing liraglutide or semaglutide for weight loss, you must screen for absolute contraindications including personal or family history of medullary thyroid carcinoma (MTC), Multiple Endocrine Neoplasia syndrome type 2 (MEN 2), and pregnancy, while counseling patients about the high likelihood of gastrointestinal side effects and the requirement for lifelong therapy to maintain weight loss. 1, 2, 3

Absolute Contraindications to Screen For

Medical History Assessment:

• Personal or family history of medullary thyroid carcinoma (MTC) - This is an absolute contraindication per FDA labeling 1, 2
• Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) - Absolute contraindication 1, 2
• Pregnancy or breastfeeding - Must discontinue semaglutide 2 months before planned pregnancy 1, 2, 3
• History of pancreatitis - Use extreme caution, though not an absolute contraindication per current guidelines 3, 2
• Personal history of any thyroid abnormalities or thyroid cancer - Requires careful evaluation 3, 4

Current Medical Conditions:

• Severe gastroparesis or problems with digesting food - Relative contraindication due to delayed gastric emptying effects 2
• Diabetic retinopathy - Requires monitoring as condition may worsen 1, 3
• Severe renal impairment - Risk increases with dehydration from vomiting 3
• History of cholelithiasis (gallstones) - Use caution as GLP-1 RAs increase gallbladder disease risk 3

Required Laboratory Testing Before Initiation

The following labs must be obtained:

• HbA1c - Baseline glucose control assessment 3, 4
• Serum creatinine - Assess renal function before starting 3, 4
• TSH, T3, T4 - Baseline thyroid function 4
• Lipid panel (triglycerides, HDL, LDL, total cholesterol) - Baseline cardiovascular risk assessment 3, 4
• Pregnancy test (βHCG) for women of childbearing potential - Must be negative before initiation 3

Note: Despite theoretical concerns, pancreatic enzymes (lipase, amylase) and calcitonin are not routinely measured in clinical practice, though one study found zero patients had these checked despite guidelines suggesting consideration 4

Medication Reconciliation Requirements

Identify high-risk drug interactions:

• Insulin or sulfonylureas - Proactively reduce doses before GLP-1 RA initiation to prevent hypoglycemia 3, 5, 1, 2
• Other GLP-1 receptor agonists - Never use concurrently 3, 5
• DPP-4 inhibitors - Never use concurrently 3, 5
• Oral medications requiring rapid absorption - May be affected by delayed gastric emptying 3
• Oral contraceptives - Consider switching to non-oral methods or adding barrier contraception for 4 weeks after initiation and each dose escalation 5

Essential Patient Counseling on Side Effects

Gastrointestinal Effects (Most Common):

• Nausea occurs in 40-44% of patients on liraglutide and semaglutide respectively, compared to 14-17% on placebo 3
• Vomiting occurs in 16-25% of patients 3
• Diarrhea occurs in 23-32% of patients 3
• Constipation occurs in 5-23% of patients 3
• Counsel that these symptoms typically diminish over time with slow dose titration 3, 5

Serious Risks Requiring Immediate Medical Attention:

• Pancreatitis - Severe abdominal pain radiating to the back, with or without vomiting, requires immediate discontinuation and emergency evaluation 1, 2, 3
• Gallbladder disease - Right upper abdominal pain, fever, or jaundice requires immediate evaluation 3, 5
• Severe allergic reactions - Swelling of face/lips/tongue/throat, difficulty breathing, severe rash, fainting, or rapid heartbeat 2
• Acute kidney injury - Can result from severe dehydration due to vomiting and diarrhea 3, 2

Hypoglycemia Risk:

• Minimal risk when used alone due to glucose-dependent mechanism 5
• Significant risk when combined with insulin or sulfonylureas - patients must recognize symptoms including shakiness, sweating, confusion, dizziness, and rapid heartbeat 1, 2, 3

Surgical and Anesthesia Precautions

Critical counseling point:

• Patients must inform all healthcare providers, especially anesthesiologists, before any surgery or procedure requiring anesthesia 5
• GLP-1 RAs delay gastric emptying, increasing aspiration risk during anesthesia 5
• Specific guidance on timing of discontinuation before elective procedures should be provided 5

Expected Outcomes and Treatment Duration

Weight Loss Expectations:

• Semaglutide 2.4 mg produces approximately 14.9% total body weight loss over 68 weeks 3, 5
• Liraglutide 3.0 mg produces approximately 8.0% total body weight loss over 56 weeks 5
• Weight loss is greater in patients without diabetes (6.1-17.4%) compared to those with diabetes (4-6.2%) 5

Lifelong Therapy Requirement:

• These medications require lifelong use for sustained weight loss 5
• Significant weight regain (11.6% of lost weight) occurs after cessation 5
• Medications work best when combined with lifestyle modifications including diet and exercise 5, 1, 2

Efficacy Assessment Timeline

Discontinuation criteria:

• Liraglutide should be discontinued if patient has not lost at least 4% of baseline body weight after 16 weeks at maintenance dose (3.0 mg) 3, 5
• Evaluate efficacy at 12-16 weeks on maximum tolerated dose 5
• Patients should be evaluated at least every 3 months for weight loss progress, side effects, and medication adherence 5

Dosing Schedule Education

Semaglutide (Ozempic/Wegovy):

• Start 0.25 mg weekly for 4 weeks, then 0.5 mg weekly for 4 weeks, then 1.0 mg weekly for 4 weeks, then 1.7 mg weekly for 4 weeks, reaching maintenance dose of 2.4 mg weekly after 16 weeks 3, 5
• Administered subcutaneously once weekly, same day each week, any time of day 1

Liraglutide (Saxenda/Victoza):

• Start 0.6 mg daily for 7 days, then 1.2 mg daily for 7 days, then 1.8 mg daily for 7 days, then 2.4 mg daily for 7 days, reaching maintenance dose of 3.0 mg daily after 4 weeks 3, 5
• Administered subcutaneously once daily, any time of day 2

Monitoring During Treatment

Ongoing surveillance:

• Blood pressure measurement - Often improves with weight loss, may require adjustment of antihypertensive medications 5
• Lipid panel monitoring - Assess improvements in cardiovascular risk factors 5
• Hydration status - Particularly important during initial titration when GI symptoms are most common 5
• Renal function monitoring - Especially in patients experiencing significant GI symptoms 3, 5

Special Populations

Women of childbearing potential:

• Must use effective contraception consistently 3
• Monthly pregnancy testing recommended 3
• Discontinue 2 months before planned pregnancy 1

Patients with diabetes:

• Proactive dose reduction of insulin or sulfonylureas required 3, 5
• More frequent glucose monitoring during titration 5, 1