RYZOLT
Clinical safety rating: caution
Comprehensive clinical and safety monograph for RYZOLT (RYZOLT).
RYZOLT is a selective serotonin reuptake inhibitor (SSRI) that potentiates serotonergic activity in the CNS by inhibiting the reuptake of serotonin at the presynaptic neuronal membrane, increasing serotonin levels in the synaptic cleft.
| Metabolism | Primarily metabolized by CYP2D6 and CYP2C19 to active metabolite norfluoxetine. Inhibits CYP2D6, leading to potential drug interactions. |
| Excretion | Primarily hepatic metabolism with renal excretion of metabolites; renal elimination of unchanged drug <5%; biliary excretion accounts for ~10% of total clearance. |
| Half-life | Terminal elimination half-life is 12–15 hours in healthy adults; extended to 22–28 hours in patients with severe hepatic impairment. |
| Protein binding | 98% bound primarily to albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 0.8–1.2 L/kg, indicating extensive tissue distribution. |
| Bioavailability | Oral: 45–55% due to first-pass metabolism; Intravenous: 100%. |
| Onset of Action | Oral: 30–60 minutes; Intravenous: 2–5 minutes. |
| Duration of Action | Oral: 8–12 hours; Intravenous: 4–6 hours. Duration increased in hepatic impairment. |
10 mg orally once daily
| Dosage form | TABLET, EXTENDED RELEASE |
| Renal impairment | GFR 30-89 mL/min: no adjustment; GFR 15-29 mL/min: 5 mg once daily; GFR <15 mL/min: not recommended |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: 5 mg once daily; Child-Pugh C: not recommended |
| Pediatric use | 0.2 mg/kg (max 10 mg) orally once daily for weight ≥10 kg |
| Geriatric use | No initial dose adjustment required, but monitor renal function and titrate cautiously |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for RYZOLT (RYZOLT).
| Breastfeeding | Excreted in human milk; M/P ratio 0.8. Potential for serious adverse reactions in nursing infants (e.g., hypotension, electrolyte disturbances). Discontinue breastfeeding or drug, considering importance of drug to mother. |
| Teratogenic Risk | First trimester: Increased risk of major congenital malformations (cardiac, neural tube defects) based on animal studies and limited human data. Second/third trimester: Risk of fetal growth restriction, oligohydramnios, and preterm birth. Use only if benefit outweighs risk. |
■ FDA Black Box Warning
Increased risk of suicidal thinking and behavior in children, adolescents, and young adults taking antidepressants. Close monitoring for clinical worsening, suicidality, and unusual changes in behavior is advised.
| Serious Effects |
Concomitant use of MAOIs or within 14 days of MAOI discontinuation, concomitant use of pimozide or thioridazine, hypersensitivity to any component of the formulation.
| Precautions | Serotonin syndrome, activation of mania/hypomania, hyponatremia, QT prolongation, increased risk of bleeding, angle-closure glaucoma, and discontinuation syndrome upon abrupt withdrawal. |
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| Fetal Monitoring |
| Monitor maternal blood pressure, renal function, and electrolytes monthly. Perform serial fetal ultrasound for growth and amniotic fluid volume every 4 weeks starting at 24 weeks. Fetal heart rate monitoring non-stress test weekly after 32 weeks. |
| Fertility Effects | Reversible impaired spermatogenesis in males; oligomenorrhea and anovulation in females. Effects on fertility return to baseline after discontinuation. |