QUASENSE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for QUASENSE (QUASENSE).
Quetiapine antagonist at dopamine D2 and serotonin 5-HT2A receptors; also affects histamine H1 and adrenergic α1 and α2 receptors.
| Metabolism | Primarily hepatic via CYP3A4; also CYP2D6 and CYP2C9. Metabolite N-desalkylquetiapine (norquetiapine) is active. |
| Excretion | Primarily renal excretion (approximately 70% as unchanged drug via glomerular filtration and tubular secretion); biliary/fecal elimination accounts for about 20% (including metabolites); 10% undergoes metabolic clearance. |
| Half-life | Terminal elimination half-life is 8–12 hours in healthy adults; prolonged to 20–30 hours in severe renal impairment (CrCl <30 mL/min), requiring dose adjustment. |
| Protein binding | 92–96% bound primarily to serum albumin; also binds to alpha-1-acid glycoprotein. |
| Volume of Distribution | 0.8–1.2 L/kg, indicating moderate distribution into total body water; penetrates well into interstitial fluid and some tissues. |
| Bioavailability | Oral: 75–90% (due to moderate first-pass metabolism; absorption is rapid and complete). |
| Onset of Action | Oral: 1–2 hours (peak plasma concentration); Intravenous: within 5–10 minutes for peak effect. |
| Duration of Action | Oral: 8–12 hours; Intravenous: 6–8 hours. Duration may be extended in renal impairment. |
100 mg orally every 12 hours.
| Dosage form | TABLET |
| Renal impairment | GFR 30-50: 100 mg every 24 hours; GFR 15-29: 100 mg every 48 hours; GFR <15: not recommended. |
| Liver impairment | Child-Pugh A: no dose adjustment; Child-Pugh B: 50 mg every 12 hours; Child-Pugh C: not recommended. |
| Pediatric use | For children aged 6-12 years: 1 mg/kg/dose (max 50 mg) every 12 hours; ages 12-18: same as adult. |
| Geriatric use | Starting dose 50 mg every 12 hours; titrate based on renal function and tolerability. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for QUASENSE (QUASENSE).
| Breastfeeding | Small amounts of ethinyl estradiol and desogestrel are excreted in breast milk. M/P ratio not established. May reduce milk production and composition. Use is generally not recommended during breastfeeding. |
| Teratogenic Risk | QUASENSE (desogestrel/ethinyl estradiol) is pregnancy category X. First trimester exposure is associated with cardiovascular and limb defects. Second and third trimester exposure may cause fetal harm due to hormonal effects, though data are limited. Contraindicated in pregnancy. |
| Fetal Monitoring |
■ FDA Black Box Warning
Increased risk of death in elderly patients with dementia-related psychosis. Antidepressants increased risk of suicidal thinking and behavior in children, adolescents, and young adults.
| Serious Effects |
["Hypersensitivity to quetiapine or any excipients"]
| Precautions | ["Neuroleptic Malignant Syndrome","Tardive dyskinesia","Metabolic changes: hyperglycemia/diabetes, dyslipidemia, weight gain","Leukopenia/neutropenia","Seizures","Hypotension/orthostatic hypotension","Cataracts","QT prolongation"] |
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| Not indicated as drug is contraindicated in pregnancy. If inadvertent exposure occurs, monitor for fetal anomalies via ultrasound. No specific maternal monitoring beyond standard pregnancy care. |
| Fertility Effects | Reversible suppression of ovulation. Normal fertility returns after discontinuation. No permanent adverse effects on fertility. |