deferiprone
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deferiprone
(de-fer-ip-rone) ,Ferriprox
(trade name)Classification
Therapeutic: antidotesPharmacologic: chelating agents
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.
Drug Guide, © 2015 Farlex and Partners