What laboratory tests are recommended for patients initiating quetiapine (Seroquel) therapy?

Laboratory Monitoring for Quetiapine

Patients initiating quetiapine require comprehensive baseline laboratory testing including fasting glucose, lipid panel, liver function tests, complete blood count, ECG, and ophthalmologic examination, followed by structured ongoing monitoring at 3 months and then annually. 1

Baseline Laboratory Assessment

Before starting quetiapine, obtain the following tests:

Metabolic Parameters

• Fasting glucose and HbA1c to screen for diabetes or prediabetes, as quetiapine is associated with hyperglycemia and new-onset diabetes 1, 2
• Fasting lipid panel (total cholesterol, LDL, HDL, triglycerides) to establish cardiovascular risk baseline, as quetiapine causes dose-dependent lipid elevations 1, 3
• Body mass index (BMI) and waist circumference to document metabolic baseline before anticipated weight gain 1
• Blood pressure measurement to establish baseline before potential increases, particularly in children and adolescents 1, 2

Organ Function Tests

• Liver function tests (ALT and AST) as quetiapine commonly causes transient, asymptomatic transaminase elevations, particularly in the first 3 weeks of treatment 1, 2, 4
• Complete blood count (CBC) to screen for baseline hematological abnormalities such as leukocytopenia and thrombocytopenia 1

Cardiac Assessment

• Electrocardiogram (ECG) to evaluate QTc interval, as quetiapine can cause QT prolongation 1, 2

Specialized Testing

• Ophthalmologic examination (slit lamp) as quetiapine was associated with cataract development in animal studies 1, 2, 4
• Pregnancy test in females of childbearing age 1

Ongoing Monitoring Schedule

First 3 Months (Intensive Phase)

• Weight/BMI monthly during the first 3 months, as weight gain occurs early and is dose-dependent 1, 3
• Blood pressure at 3 months, then annually thereafter 1
• Fasting glucose and lipid panel at 3 months, then annually 1

After 3 Months (Maintenance Phase)

• Weight/BMI quarterly after the initial 3-month period 1
• Fasting glucose and lipid panel annually 1
• Blood pressure annually 1

Medication-Specific Monitoring

• Ophthalmologic examinations every 6 months while on quetiapine therapy, as recommended by the FDA 1, 2
• Liver function tests periodically, particularly during the first 3 weeks when transaminase elevations most commonly occur 1, 2, 4
• Complete blood count periodically to detect potential hematological changes 1

Clinical Monitoring

• Orthostatic vital signs during dose titration to monitor for orthostatic hypotension 1
• Extrapyramidal symptoms (EPS) assessment regularly, though quetiapine has placebo-level incidence of EPS across its dose range 1, 5

Special Population Considerations

High-Risk Patients

• Patients with pre-existing diabetes or prediabetes require more frequent glucose monitoring, with consideration of monthly checks initially 1
• Adolescents warrant closer monitoring for metabolic effects, as they experience greater weight gain (mean 11.24 kg vs 4.81 kg in adults) and more pronounced lipid changes than adults 1
• Elderly patients require closer monitoring for metabolic effects and orthostatic hypotension 1

Common Pitfalls to Avoid

• Do not rely solely on fasting glucose measurements in adolescents, as postprandial lipid testing may reveal metabolic abnormalities not apparent in fasting samples 6
• Do not assume low-dose quetiapine (<150 mg/day) is free from metabolic risk—dose-dependent effects exist, but even low doses can cause clinically significant metabolic alterations 3
• Do not skip the 6-month ophthalmologic examinations, as this is an FDA-recommended monitoring parameter specific to quetiapine 1, 2
• Do not overlook transaminase elevations in the first 3 weeks of treatment, though they are usually transient and asymptomatic 1, 2, 4