deferiprone

(de-fer-ip-rone) deferiprone,

Ferriprox

(trade name)

Classification

Therapeutic: antidotes
Pharmacologic: chelating agents
Pregnancy Category: D

Indications

Treatment of transfusional iron overload due to thalassemia when other chelation regimens are inadequate.

Action

Bonds with ferric ions to form neutral complexes which are then eliminated.

Therapeutic effects

Decrease in iron overload as reflected in decreased ferritin levels.

Pharmacokinetics

Absorption: Well absorbed following oral administration.Distribution: Unk.Metabolism and Excretion: Mostly metabolized (by UGT 1A6 enzyme system), 75–90% excreted in urine as metabolites.Half-life: 1.9 hr.

Time/action profile (blood levels)

ROUTE	ONSET	PEAK	DURATION
PO	within 5–10 min	1–2 hr	8–12 hr

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Obstetric: Pregnancy should be avoided; Lactation: Breast feeding not recommended.Use Cautiously in: Renal/hepatic impairment (safety and effectiveness not established); Any risk/history of QT prolongation including HF, bradycardia, diuretic use, cardiac hypertrophy, hypokalemia, hypomagnesemia; Pediatric: Safe and effective use in children has not been established.

Adverse Reactions/Side Effects

Central nervous system

headache

Cardiovascular

Torsades de Pointes (life-threatening)

Gastrointestinal

abdominal pain (most frequent)
nausea (most frequent)
change in appetite
vomiting
↑ liver enzymes

Genitourinary

chromaturia (most frequent)

Hematologic

agranulocytosis (life-threatening)
neutropenia

Musculoskeletal

arthralgia
arthropathy
back pain
extremity pain

Miscellaneous

↓ zinc levels

Interactions

Drug-Drug interaction

Concurrent use of other drugs that cause neutropenia/agranulocytosis may ↑ risk of neutropenia/agranulocytosis. May also chelate other concurrently administered polyvalent cations in mineral supplements and antacids, including iron, aluminum and zinc ; wait 4 hr between administration.

Route/Dosage

Oral (Adults) 25 mg/kg three times daily, may be adjusted up to 33 mg/kg three times daily (range 75–99 mg/kg/day in divided doses). Dose should be rounded to the nearest 250 mg (1/2 tablet).

Availability

Tablets: 500 mg

Nursing implications

Nursing assessment

.
Lab Test Considerations: Monitor serum ferritin every 2–3 mo to assess efficacy. If serum ferritin falls consistently below 500 mcg/L, consider temporarily interripting deferiprone therapy.
- Measure ANC before starting and weekly during therapy. Interrupt deferiprone if neutropenia (ANC <1.5 X 10⁹/L) or if infection develops. If ANC <1.5 X 10⁹/L and >0.5 X 10⁹/L, obtain CBC with WBC corrected for presence of nucleated red blood cells, ANC, and platelet count daily until recovery (ANC ≥1.5 X 10⁹/L. For agranulocytosis (ANC <0.5 X 10⁹/L), Consider hospitalization and manage as clinically appropriate. Do not resume deferiprone in patients who develop agranulocytosis or rechallenge patients who develop neutropenia, unless benefits outweigh risks.
- Monitor serum AST and ALT monthly during therapy. Interrupt therapy if persistent ↑ in serum transaminases occurs.
- Monitor plasma zinc levels. ↓ may occur and may require supplementation.

Potential Nursing Diagnoses

Risk for infection (Adverse Reactions)

Implementation

Oral: Administer first dose in the morning, second dose midday, and third dose in the evening. May be taken with meals to decrease nausea.

Patient/Family Teaching

Instruct patient to take deferiprone 3 times/day. Take missed doses as soon as remembered, but not just before next dose. Do not double doses.
Advise patient to stop therapy and notify health care professional immediately if signs and symptoms of infection (fever, sore throat) or if palpitations, dizziness, syncope, or seizures occur.
Inform patient that reddish/brown urine may occur; common and not harmful.
Advise female patients to use contraception and avoid breastfeeding during therapy. If pregnancy is planned or suspected, notify health care professional promptly.

Evaluation/Desired Outcomes

Decrease in serum ferritin levels.