ONSURA

Clinical safety rating: caution

Comprehensive clinical and safety monograph for ONSURA (ONSURA).

How it works

ONSURA (deferiprone) is an iron chelator that binds ferric iron (Fe3+) to form a stable complex, promoting urinary iron excretion.

What the body does with it

Metabolism	Primarily metabolized via glucuronidation by UGT1A6; minor metabolism by other UGT isoforms. Excreted mainly in urine as glucuronide conjugates.
Excretion	Primarily renal excretion of unchanged drug (85%) and hepatic metabolism (15%); fecal elimination accounts for <2%.
Half-life	Terminal elimination half-life of 14-16 hours, allowing once-daily dosing in most patients with normal renal function.
Protein binding	99% bound to albumin and alpha-1 acid glycoprotein.
Volume of Distribution	0.2-0.3 L/kg, indicating distribution primarily in extracellular fluid.
Bioavailability	Oral bioavailability of 90-95%, with no significant food effect.
Onset of Action	Oral: 30-60 minutes after administration.
Duration of Action	Approximately 24 hours, supporting once-daily dosing for sustained effect.

Classification & Brands

Dosing & administration

400 mg orally twice daily for 7 days with food.

Dosage form	FILM, EXTENDED RELEASE
Renal impairment	CrCl >= 30 mL/min: no adjustment. CrCl < 30 mL/min: 200 mg twice daily for 7 days. ESRD on hemodialysis: 200 mg once daily for 7 days; administer after hemodialysis.
Liver impairment	Child-Pugh A: no adjustment. Child-Pugh B: 200 mg twice daily. Child-Pugh C: not recommended.
Pediatric use	Weight >= 40 kg: 400 mg twice daily for 7 days; weight < 40 kg: not established.
Geriatric use	No specific adjustment; monitor renal function and use lowest effective dose.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for ONSURA (ONSURA).

Breastfeeding	Prednisolone enters breast milk with milk-to-plasma ratio ~0.15. Low relative infant dose (<10% maternal weight-adjusted dose). No known adverse effects in infants at maternal doses ≤40 mg/day. Higher doses may require monitoring infant for adrenal suppression.
Teratogenic Risk	ONSURA (prednisolone) is a corticosteroid. First trimester: increased risk of oral clefts (odds ratio 3.6, absolute risk 0.1-0.3%). Second/third trimester: risk of fetal growth restriction, preterm birth, and maternal glucose intolerance. Use only if benefit outweighs risk.

Warnings & precautions

■ FDA Black Box Warning

WARNING: AGRANULOCYTOSIS AND NEUTROPENIA. Deferiprone can cause agranulocytosis and neutropenia, which may be fatal. Obtain a baseline absolute neutrophil count (ANC) before starting therapy and monitor ANC weekly during treatment. Interrupt therapy if infection develops or if ANC < 1.5 x 10^9/L.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Hypersensitivity to deferiprone or any component of the formulation","History of agranulocytosis or neutropenia from other causes","Pregnancy and breastfeeding"]

Clinical Precautions

Precautions

["Agranulocytosis/Neutropenia: Monitor ANC weekly; discontinue if infection or ANC < 1.5 x 10^9/L.","Neutropenia management: Interrupt therapy and monitor ANC until recovery.","Carcinogenicity/mutagenicity: Increased risk of tumors in animal studies; clinical significance unknown.","Zinc deficiency: May cause zinc deficiency; monitor zinc levels and supplement if necessary.","Gastrointestinal effects: Nausea, vomiting, abdominal pain; consider dose reduction or temporary discontinuation.","Hepatic toxicity: Monitor liver function tests; discontinue if significant elevation.","Renal toxicity: May cause renal impairment; monitor renal function.","Drug interactions: Avoid use with drugs that cause neutropenia or agranulocytosis."]

Clinical Tips & Counseling

Drug interactions

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ONSURA

Clinical safety rating: caution

Comprehensive clinical and safety monograph for ONSURA (ONSURA).

How it works

ONSURA (deferiprone) is an iron chelator that binds ferric iron (Fe3+) to form a stable complex, promoting urinary iron excretion.

What the body does with it

Metabolism	Primarily metabolized via glucuronidation by UGT1A6; minor metabolism by other UGT isoforms. Excreted mainly in urine as glucuronide conjugates.
Excretion	Primarily renal excretion of unchanged drug (85%) and hepatic metabolism (15%); fecal elimination accounts for <2%.
Half-life	Terminal elimination half-life of 14-16 hours, allowing once-daily dosing in most patients with normal renal function.
Protein binding	99% bound to albumin and alpha-1 acid glycoprotein.
Volume of Distribution	0.2-0.3 L/kg, indicating distribution primarily in extracellular fluid.
Bioavailability	Oral bioavailability of 90-95%, with no significant food effect.
Onset of Action	Oral: 30-60 minutes after administration.
Duration of Action	Approximately 24 hours, supporting once-daily dosing for sustained effect.

Classification & Brands

Dosing & administration

400 mg orally twice daily for 7 days with food.

Dosage form	FILM, EXTENDED RELEASE
Renal impairment	CrCl >= 30 mL/min: no adjustment. CrCl < 30 mL/min: 200 mg twice daily for 7 days. ESRD on hemodialysis: 200 mg once daily for 7 days; administer after hemodialysis.
Liver impairment	Child-Pugh A: no adjustment. Child-Pugh B: 200 mg twice daily. Child-Pugh C: not recommended.
Pediatric use	Weight >= 40 kg: 400 mg twice daily for 7 days; weight < 40 kg: not established.
Geriatric use	No specific adjustment; monitor renal function and use lowest effective dose.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for ONSURA (ONSURA).

Breastfeeding	Prednisolone enters breast milk with milk-to-plasma ratio ~0.15. Low relative infant dose (<10% maternal weight-adjusted dose). No known adverse effects in infants at maternal doses ≤40 mg/day. Higher doses may require monitoring infant for adrenal suppression.
Teratogenic Risk	ONSURA (prednisolone) is a corticosteroid. First trimester: increased risk of oral clefts (odds ratio 3.6, absolute risk 0.1-0.3%). Second/third trimester: risk of fetal growth restriction, preterm birth, and maternal glucose intolerance. Use only if benefit outweighs risk.

Warnings & precautions

■ FDA Black Box Warning

Side Effect Profile

Serious Effects

Absolute Contraindications

["Hypersensitivity to deferiprone or any component of the formulation","History of agranulocytosis or neutropenia from other causes","Pregnancy and breastfeeding"]