ISIBLOOM
Clinical safety rating: caution
Comprehensive clinical and safety monograph for ISIBLOOM (ISIBLOOM).
ISIBLOOM is a selective serotonin reuptake inhibitor (SSRI) that increases serotonergic neurotransmission by blocking the reuptake of serotonin at the presynaptic neuron, thereby enhancing serotonin levels in the synaptic cleft.
| Metabolism | Hepatic metabolism primarily via CYP2D6 and CYP3A4 isoenzymes, producing active metabolites (e.g., norISIBLOOM). |
| Excretion | Renal excretion of unchanged drug accounts for approximately 60% of elimination; biliary/fecal excretion accounts for 35%; minor metabolism (<5%) via CYP3A4. |
| Half-life | Terminal elimination half-life is 12 hours (range 10–14 hours) in healthy adults, permitting twice-daily dosing; prolonged to 24–30 hours in severe renal impairment (CrCl <30 mL/min). |
| Protein binding | 92% bound to serum albumin and alpha-1-acid glycoprotein. |
| Volume of Distribution | 0.8 L/kg (range 0.6–1.0 L/kg), indicating extensive extravascular distribution. |
| Bioavailability | Oral: 85% (range 75–95%) with high-fat meal increasing absorption by approximately 15%. |
| Onset of Action | Oral: 30–60 minutes; Intravenous: within 5 minutes; Intramuscular: 10–15 minutes. |
| Duration of Action | Oral: 8–12 hours; Intravenous: 6–8 hours; Intramuscular: 8–10 hours. Duration may be extended in hepatic impairment. |
Adults: 200 mg orally once daily; increase to 400 mg once daily after 2 weeks if tolerated. Maximum dose: 600 mg once daily.
| Dosage form | TABLET |
| Renal impairment | GFR ≥60 mL/min: no adjustment. GFR 30-59 mL/min: reduce dose to 200 mg daily. GFR 15-29 mL/min: 200 mg every 48 hours. GFR <15 mL/min or dialysis: not recommended. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50% (maximum 200 mg daily). Child-Pugh C: contraindicated. |
| Pediatric use | Children ≥12 years: 200 mg orally once daily; increase to 400 mg once daily after 2 weeks. Children 6-11 years: 4 mg/kg orally once daily (max 200 mg); increase to 8 mg/kg once daily (max 400 mg) after 2 weeks. Children <6 years: not established. |
| Geriatric use | Initiate at 200 mg once daily; monitor renal function and titrate slowly due to age-related decline in GFR. Maximum dose 400 mg daily. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for ISIBLOOM (ISIBLOOM).
| Breastfeeding | Contraindicated during breastfeeding. ISIBLOOM is excreted in human milk with a milk-to-plasma ratio of approximately 0.8. Potential for serious adverse reactions in nursing infants, including renal toxicity and growth impairment. Discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother. |
| Teratogenic Risk | Pregnancy Category X. First trimester: High risk of major congenital malformations including neural tube defects, cardiovascular anomalies, and orofacial clefts based on animal studies and limited human data. Second and third trimesters: Risk of fetal growth restriction, oligohydramnios, and fetal renal impairment. Avoid in pregnant women; effective contraception required during treatment. |
■ FDA Black Box Warning
ISIBLOOM increases the risk of suicidal thinking and behavior in children, adolescents, and young adults with major depressive disorder and other psychiatric disorders. Patients of all ages should be closely monitored for clinical worsening, suicidality, or unusual changes in behavior.
| Serious Effects |
Concomitant use with MAOIs, pimozide, thioridazine; known hypersensitivity to ISIBLOOM; use in patients with uncontrolled narrow-angle glaucoma.
| Precautions | Serotonin syndrome, discontinuation syndrome, activation of mania/hypomania, hyponatremia, abnormal bleeding, increased intraocular pressure, sexual dysfunction, and bone fractures. |
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| Fetal Monitoring | Monitor maternal renal function (serum creatinine, BUN) and blood pressure at baseline and monthly during pregnancy. Perform fetal ultrasound at 18-20 weeks to assess for congenital anomalies. Serial growth scans (every 4 weeks) from 24 weeks to detect intrauterine growth restriction. Fetal echocardiography if cardiac anomaly suspected. In late pregnancy, monitor amniotic fluid volume via ultrasound. |
| Fertility Effects | In preclinical studies, ISIBLOOM caused reduced fertility in female rats due to ovarian dysfunction and altered estrous cycles. In humans, no adequate data are available; however, based on mechanism of action, potential for reversible impairment of fertility in females. Males: No significant effects observed. |