How Long Until Quetiapine (Seroquel) Is Eliminated from the Body
Quetiapine is primarily eliminated from the body within 30-60 hours (approximately 5-10 half-lives) after the last dose, with complete clearance typically occurring within 2-3 days for most individuals.
Pharmacokinetic Properties of Quetiapine
Quetiapine has specific pharmacokinetic properties that determine how long it remains in the body:
Half-life: According to the FDA drug label, quetiapine has a mean terminal half-life of about 6 hours within the proposed clinical dose range 1. Other studies report half-lives ranging from:
Metabolism: Quetiapine is extensively metabolized by the liver, with less than 1% excreted unchanged 1. The primary metabolic pathways are:
- Sulfoxidation to the sulfoxide metabolite
- Oxidation to the parent acid metabolite
- Formation of N-desalkyl quetiapine (norquetiapine), an active metabolite
Elimination: Following a single oral dose, approximately 73% of quetiapine is recovered in urine and 20% in feces 1.
Time to Complete Elimination
The general pharmacological principle is that a drug is considered effectively eliminated after 5-6 half-lives. For quetiapine:
- At 5 half-lives (30-42 hours): Approximately 97% of the drug is eliminated
- At 6 half-lives (36-50 hours): Approximately 98.5% of the drug is eliminated
- Complete elimination (>99%): Typically occurs within 2-3 days
This is consistent with PET scan studies showing that dopamine D2 receptor occupancy drops to baseline levels within 26 hours after discontinuation 2.
Factors Affecting Elimination Time
Several factors can influence how long quetiapine remains in the body:
- Age: Oral clearance is reduced by approximately 40% in elderly patients (≥65 years) 1
- Hepatic impairment: Patients with severe liver dysfunction show 50% lower clearance 1
- Renal impairment: Patients with severe renal impairment (CrCl=10-30 mL/min/1.73 m²) have 25% lower oral clearance 1
- Formulation: Extended-release formulations may prolong the elimination process
Clinical Implications
When considering the complete elimination of quetiapine from the body:
Perioperative management: Based on the general principle that 5 half-lives are required for complete elimination 5, quetiapine would be expected to be eliminated within 2-3 days.
Drug testing: Quetiapine and its metabolites would likely be undetectable in standard drug tests after 3-5 days.
Switching medications: When transitioning to another medication, allowing 2-3 days after discontinuing quetiapine would minimize potential drug interactions.
Summary
Quetiapine has a relatively short half-life of approximately 6 hours, resulting in complete elimination from the body within 2-3 days for most individuals. Special populations such as elderly patients or those with hepatic or renal impairment may experience longer elimination times due to reduced clearance.