Ferriprox

Deferiprone.

Deferiprone is a medicine that removes iron from the body.
FC tab: The active substance is deferiprone 500 mg/tablet.
Oral soln: Each ml of oral solution contains 100 mg deferiprone.
Excipients/Inactive Ingredients: FC tab: Core tablet: Microcrystalline cellulose, Magnesium stearate, Colloidal silicon dioxide.
Coating: Hypromellose, Macrogol, Titanium dioxide.
Oral soln: Each ml of oral solution contains 0.4 mg Sunset Yellow (E110).
Purified water, Hydroxyethylcellulose, Glycerol, Concentrated hydrochloric acid, Artificial cherry flavour, Peppermint oil, Sunset Yellow (E110), Sucralose (E955).

Pharmacotherapeutic Group: Iron chelating agents. ATC Code: V03AC02.
Pharmacology: Pharmacodynamics: The active substance is deferiprone (3-hydroxy-1,2-dimethylpyridin-4-one), a bidentate ligand which binds to iron in a 3:1 molar ratio.
Clinical studies have demonstrated that deferiprone is effective in promoting iron excretion and that a dose of 25 mg/kg three times per day can prevent the progression of iron accumulation as assessed by serum ferritin, in patients with transfusion-dependent thalassaemia. However, chelation therapy may not necessarily protect against iron-induced organ damage.
Deferiprone has been investigated in 247 patients in two phase III trials and a compassionate use programme. Serum ferritin was chosen as the primary efficacy criterion in the studies. In one study of two‐year duration deferiprone was compared to deferoxamine. The mean serum ferritin levels were not significantly different in the two treatment groups, but mean hepatic iron concentration in deferiprone treated patients seems to increase more than in deferoxamine treated patients. Therefore deferiprone at the recommended dose could be less effective than deferoxamine.
The other study was a supportive open, non-comparative study. In this study patients maintained serum ferritin values at pre-study levels. The primary end-point was the incidence of agranulocytosis, which occurred at a frequency of 1.2%.
Pharmacokinetics: FC tab: Deferiprone is rapidly absorbed from the upper part of the gastro-intestinal tract. Peak serum concentration is reported to occur 45 to 60 minutes following a single dose in fasted patients. This may be extended to 2 hours in fed patients. Deferiprone is metabolised predominantly to a glucuronide conjugate. This metabolite lacks ironbinding capacity due to inactivation of the 3-hydroxy group of deferiprone. In humans, deferiprone is eliminated mainly via the kidneys with reports of 75% to 90% of the ingested dose being recovered in the urine in the first 24 hours, in the form of free deferiprone, the glucuronide metabolite and the iron-deferiprone complex.
Oral soln: Absorption: Deferiprone is rapidly absorbed from the upper part of the gastrointestinal tract. Peak serum concentration is reported to occur 45 to 60 minutes following a single dose in fasted patients. This may be extended to 2 hours in fed patients.
Following a dose of 25 mg/kg, lower peak serum concentrations have been detected in patients in the fed state (85 µmol/l) than in the fasting state (126 µmol/l), although there was no decrease in the amount of deferiprone absorbed when it was given with food.
Biotransformation: Deferiprone is metabolised predominantly to a glucuronide conjugate. This metabolite lacks iron‐binding capability due to inactivation of the 3 hydroxy-group of deferiprone. Peak serum concentrations of the glucuronide occur 2 to 3 hours after administration of deferiprone.
Elimination: In humans, deferiprone is eliminated mainly via the kidneys; 75% to 90% of the ingested dose is reported as being recovered in the urine in the first 24 hours, in the form of free deferiprone, the glucuronide metabolite and the iron‐deferiprone complex. A variable amount of elimination via the faeces has been reported. The elimination half‐life in most patients is 2 to 3 hours.
Toxicology: Preclinical safety data: Non-clinical studies have been conducted in animal species including mice, rats, rabbits, dogs and monkeys.
The most common findings in non‐iron‐loaded animals at doses of 100 mg/kg/day and above were hematologic effects such as bone marrow hypocellularity, and decreased WBC, RBC and/or platelet counts in peripheral blood.
Atrophy of the thymus, lymphoid tissues, and testis, and hypertrophy of the adrenals, were reported at doses of 100 mg/kg/day or greater in non-iron-loaded animals.
No carcinogenicity studies in animals have been conducted with deferiprone. The genotoxic potential of deferiprone was evaluated in a set of in vitro and in vivo tests. Deferiprone did not show direct mutagenic properties; however, it did display clastogenic characteristics in in vitro assays and in vivo in animals.
Deferiprone was teratogenic and embryotoxic in reproductive studies in non‐iron‐loaded rats and rabbits at doses at least as low as 25 mg/kg/day. No prenatal and postnatal reproductive studies have been conducted in animals.

Ferriprox is indicated for the treatment of iron overload in patients with thalassaemia major when deferoxamine therapy is contraindicated or inadequate.

FC tab: The amount of deferiprone to be taken will depend on the patient's weight. Ferriprox is usually prescribed as 25 mg/kg body weight, calculated to the nearest half tablet, to be taken three (3) times per day for a total daily dose of 75 mg/kg body weight. Take the first dose in the morning. Take the second dose midday. Take the third dose in the evening. It is not necessary to take Ferriprox with food. However, it may be easier to remember to take the medication, if taken with meals. Ferriprox will be most effective if the patient does not miss any doses. If the patient does miss one dose take it as soon as remembered and take the next dose at its regularly scheduled time. If the patient misses more than one dose, do not take the missed tablets, just continue with the normal schedule. Do not change the daily dose without first consulting with the doctor.
Very limited data are available on Ferriprox use in children under 6 years of age; therefore, the use of Ferriprox in this group should not be recommended unless the potential benefits outweigh the potential risks.
There are no reports of overdose with deferiprone.
Oral soln: For oral use.
Deferiprone therapy should be initiated and maintained by a physician experienced in the treatment of patients with thalassaemia.
Deferiprone is usually given as 25 mg/kg body weight, orally, three times a day for a total daily dose of 75 mg/kg body weight. Dose per kilogram body weight should be calculated to the nearest 2.5 ml. See Table 1 for recommended doses for body weights at 10 kg increments.
Doses above 100 mg/kg/day are not recommended because of the potentially increased risk of adverse reactions; chronic administration of more than 2.5 times the maximum recommended dose has been associated with neurological disorders (see Precautions, Adverse Reactions and Overdosage).
There are limited data available on the use of deferiprone in children between 6 and 10 years of age, and no data on deferiprone use in children under 6 years of age.
Due to the serious nature of agranulocytosis, that can occur with the use of deferiprone, special monitoring is required for all patients. Caution must be used when the patients' absolute neutrophil count (ANC) is low, as well as when treating patients with renal insufficiency or hepatic dysfunction. (See Precautions.)
Dose table: To obtain a dose of about 75 mg/kg/day, use the volume of oral solution suggested in the following table for the body weight of the patient. Sample body weights at 10 kg increments are listed. (See Table 1.)

Click on icon to see table/diagram/image

Oral soln: No cases of acute overdose have been reported. However, neurological disorders (such as cerebellar symptoms, diplopia, lateral nystagmus, psychomotor slowdown, hand movements and axial hypotonia) have been observed in children who had been voluntarily prescribed more than 2.5 times the maximum recommended dose of 100 mg/kg/day for several years. The neurological disorders progressively regressed after deferiprone discontinuation.
In case of overdose, close clinical supervision of the patient is required.

Hypersensitivity to the active substance or to any of the excipients.
History of recurrent episodes of neutropenia (low white blood cell count).
History of agranulocytosis (very low white blood cell count <0.5 x 10⁹/L).
Pregnancy or breast feeding (see Use in Pregnancy & Lactation).
Due to the unknown mechanism of deferiprone‐induced neutropenia, patients must not take medicinal products known to be associated with neutropenia or those that can cause agranulocytosis (see Interactions).

FC tab: The most serious undesirable effect of deferiprone is the occurrence of a very low white blood cell count. This condition, known as severe neutropenia or agranulocytosis, has occurred in about 1 out of 100 patients who have taken deferiprone in clinical studies. Because white blood cells help to fight infection, a low white blood cell count may place the patient at risk to develop a serious infection. If an infection of this nature is not discovered and treated early, it could cause death. The doctor will ask a blood test (to check the white blood cell count) performed regularly, as frequently as every week. It is very important to keep all of these appointments. Report immediately to the doctor any symptoms of infection such as: fever, sore throat or flu-like symptoms.
The doctor may monitor the patient's serum ALT level at regular intervals during therapy with Ferriprox, and interruption of therapy may be considered if a persistent increase in serum ALT levels occurs.
Ferriprox should be prescribed by a Hematologist, Pediatrician or other Medical Physician.
The doctor will also ask the patient to come in for tests to monitor body iron load. In addition, he or she also might ask for the patient to undergo liver biopsies.
Patients with iron overload are at increased risk of cancer. In these circumstances, the impact of deferiprone is not known.
The positive and negative effects of iron chelation can only be demonstrated after many years. Therefore, further studies are ongoing. In addition, cancer-predicting studies are underway.
Driving and using machines: There is no evidence that Ferriprox affects the ability to drive or use machinery.
Oral soln: Neutropenia/Agranulocytosis: Deferiprone has been shown to cause neutropenia, including agranulocytosis. The patient's neutrophil count should be monitored every week.
In clinical trials, weekly monitoring of the neutrophil count has been effective in identifying cases of neutropenia and agranulocytosis. Neutropenia and agranulocytosis resolved once therapy was withdrawn. If the patient develops an infection while on deferiprone, therapy should be interrupted and the neutrophil count monitored more frequently. Patients should be advised to report immediately to their physician any symptoms indicative of infection such as fever, sore throat and flu-like symptoms.
Suggested management of cases of neutropenia is outlined below. It is recommended that such a management protocol be in place prior to initiating any patient on deferiprone treatment.
Treatment with deferiprone should not be initiated if the patient is neutropenic. The risk of agranulocytosis and neutropenia is higher, if the baseline absolute neutrophil count (ANC) is less than 1.5x10⁹/l.
In the event of neutropenia: Instruct the patient to immediately discontinue deferiprone and all other medicinal products with a potential to cause neutropenia. The patient should be advised to limit contact with other individuals in order to reduce the risk of infection. Obtain a complete blood cell (CBC) count, with a white blood cell (WBC) count, corrected for the presence of nucleated red blood cells, a neutrophil count, and a platelet count immediately upon diagnosing the event and then repeat daily. It is recommended that following recovery from neutropenia, weekly CBC, WBC, neutrophil and platelet counts continue to be obtained for three consecutive weeks, to ensure that the patient recovers fully. Should any evidence of infection develop concurrently with the neutropenia, the appropriate cultures and diagnostic procedures should be performed and an appropriate therapeutic regimen instituted.
In the event of severe neutropenia or agranulocytosis: Follow the guidelines above and administer appropriate therapy such as granulocyte colony stimulating factor, beginning the same day that the event is identified; administer daily until the condition resolves. Provide protective isolation and if clinically indicated, admit patient to the hospital.
Limited information is available regarding rechallenge. Therefore, in the event of neutropenia, rechallenge is not recommended. In the event of agranulocytosis, a rechallenge is contraindicated.
Carcinogenicity/mutagenicity/effects on fertility: In view of the genotoxicity results, a carcinogenic potential of deferiprone cannot be excluded (see Pharmacology: Toxicology under Actions). No animal studies to evaluate the potential effects of deferiprone on fertility have been reported.
Serum ferritin concentration/plasma Zn²⁺ concentration: It is recommended that serum ferritin concentrations, or other indicators of body iron load, be monitored every two to three months to assess the long-term effectiveness of the chelation regimen in controlling the body iron load. Interruption of therapy with deferiprone should be considered if serum ferritin measurements fall below 500 µg/l.
Monitoring of plasma Zn²⁺ concentration, and supplementation in case of a deficiency, is recommended.
HIV positive or other immune compromised patients: No data are available on the use of deferiprone in HIV positive or in other immune compromised patients. Given that deferiprone can be associated with neutropenia and agranulocytosis, therapy in immune compromised patients should not be initiated unless potential benefits outweigh potential risks.
Renal or hepatic impairment and liver fibrosis: There are no data available on the use of deferiprone in patients with renal or hepatic impairment. Since deferiprone is eliminated mainly via the kidneys, there may be an increased risk of complications in patients with impaired renal function. Similarly, as deferiprone is metabolised in the liver, caution must be exercised in patients with hepatic dysfunction. Renal and hepatic function should be monitored in this patient population during deferiprone therapy. If there is a persistent increase in serum alanine aminotransferase (ALT), interruption of deferiprone therapy should be considered.
In thalassaemia patients there is an association between liver fibrosis and iron overload and/or hepatitis C. Special care must be taken to ensure that iron chelation in patients with hepatitis C is optimal. In these patients careful monitoring of liver histology is recommended.
Discoloration of urine: Patients should be informed that their urine may show a reddish/brown discoloration due to the excretion of the iron‐deferiprone complex.
Chronic overdose and neurological disorders: Neurological disorders have been observed in children treated with 2.5 to 3 times the recommended dose for several years. Prescribers are reminded that the use of doses above 100 mg/kg/day are not recommended (see Dosage & Administration, Adverse Reactions and Overdosage).
Excipients: Ferriprox oral solution contains the colouring agent Sunset Yellow (E110) which may cause allergic reactions.
Effects on ability to drive and use machines: No studies on the effects on the ability to drive and use machines have been performed.
Use in Pregnancy & Lactation: FC tab: Do not take this medication if breast-feeding, pregnant, or trying to become pregnant. This medication could seriously harm the baby. The patient must use effective contraception while taking Ferriprox. Ask the doctor which method is best. If the patient becomes pregnant while taking Ferriprox, stop taking the medicine immediately and tell the doctor.

FC tab: Do not take this medication if breast-feeding, pregnant, or trying to become pregnant. This medication could seriously harm the baby. The patient must use effective contraception while taking Ferriprox. Ask the doctor which method is best. If the patient becomes pregnant while taking Ferriprox, stop taking the medicine immediately and tell the doctor.
Oral soln: Pregnancy: There are no adequate data from the use of deferiprone in pregnant women. Studies in animals have shown reproductive toxicity (see Pharmacology: Toxicology: Preclinical safety data under Actions). The potential risk for humans is unknown.
Women of childbearing potential must be advised to avoid pregnancy due to the clastogenic and teratogenic properties of the medicinal product. These women should be counselled to take contraceptive measures and must be advised to immediately stop taking deferiprone if they become pregnant or plan to become pregnant (see Contraindications).
Lactation: It is not known whether deferiprone is excreted in human milk. No prenatal and postnatal reproductive studies have been conducted in animals. Deferiprone must not be used by breast‐feeding mothers. If treatment is unavoidable, breast feeding must be stopped.

FC tab: Like all medicines, deferiprone can have side effects.
The most serious undesirable effect of deferiprone is the occurrence of a very low white blood cell count. This condition, known as severe neutropenia or agranulocytosis, has occurred in about 1 out of 100 patients who have taken deferiprone in clinical studies. A low white blood cell count can also be associated with an infection. Report immediately to the doctor any symptoms of infection such as: Fever, sore throat or flu-like symptoms.
Some of the patients enrolled in clinical studies with deferiprone developed joint pain and swelling. In most patients, the pain disappeared while still taking Ferriprox.
Some patients treated with Ferriprox have experienced some or all of the following symptoms: increase in liver enzymes, abdominal pain, nausea, vomiting, diarrhea and increase in appetite. Most patients find that these undesirable effects disappear after a few days to a few weeks of continued treatment. If patient experiences nausea or vomiting, it may help to take Ferriprox with some food.
The urine may become reddish/brown in colour. This is the most common undesirable effect of deferiprone and it is not harmful.
If the patient notices any side effects, please inform the doctor, pharmacist or the local distributing company immediately, who will in turn communicate it to the Medical Information Division at Apotex (Canada) by calling: +1 (416) 401-7780.
Oral soln: The most serious adverse reaction reported in clinical trials with deferiprone is agranulocytosis (neutrophils <0.5x10⁹/l), with an incidence of 1.1% (0.6 cases per 100 patient‐years of treatment) (see Precautions). The observed incidence of the less severe form of neutropenia (neutrophils <1.5x10⁹/l) is 4.9% (2.5 cases per 100 patient‐years). This rate should be considered in the context of the underlying elevated incidence of neutropenia in thalassaemia patients, particularly in those with hypersplenism.
Episodes of diarrhoea, mostly mild and transient, have been reported in patients treated with deferiprone. Gastrointestinal effects are more frequent at the beginning of therapy and resolve in most patients within a few weeks without the discontinuation of treatment. In some patients it may be beneficial to reduce the dose of deferiprone and then scale it back up to the former dose. Arthropathy events, which ranged from mild pain in one or more joints to severe arthritis with effusion and significant disability, have also been reported in patients treated with deferiprone. Mild arthropathies are generally transient.
Increased levels of serum liver enzymes have been reported in patients taking deferiprone. In the majority of these patients, the increase was asymptomatic and transient, and returned to baseline without discontinuation or decreasing the dose of deferiprone (see Precautions).
Some patients experienced progression of fibrosis associated with an increase in iron overload or hepatitis C.
Low plasma zinc levels have been associated with deferiprone, in a minority of patients. The levels normalised with oral zinc supplementation.
Neurological disorders (such as cerebellar symptoms, diplopia, lateral nystagmus, psychomotor slow down, hand movements and axial hypotonia) have been observed in children who had been voluntarily prescribed more than 2.5 times the maximum recommended dose of 100 mg/kg/day for several years. The neurological disorders progressively regressed after deferiprone discontinuation (see Dosage & Administration, Precautions and Overdosage).
Adverse reaction frequencies: Very common (≥1/10), Common (≥1/100 to <1/10), Uncommon (≥1/1,000 to <1/100). (See Table 2.)

Click on icon to see table/diagram/image

FC tab: Tell the doctor about all other medications currently taken, even ones that can be bought without a prescription. The doctor can tell which medications can be safely taken with Ferriprox.
Since this compound binds to metallic cations, the potential exists for interactions between deferiprone and trivalent cation-dependent medicinal products such as aluminium-based antacids.
Based on the reported adverse interaction that can occur between deferoxamine and vitamin C, caution should be used when administering concurrent deferiprone and vitamin C.
Oral soln: Interactions between deferiprone and other medicinal products have not been reported. However, since deferiprone binds to metallic cations, the potential exists for interactions between deferiprone and trivalent cation‐dependent medicinal products such as aluminium‐based antacids. Therefore, it is not recommended to concomitantly ingest aluminium‐based antacids and deferiprone.
The safety of concurrent use of deferiprone and vitamin C has not been formally studied. Based on the reported adverse interaction that can occur between deferoxamine and vitamin C, caution should be used when administering deferiprone and vitamin C concurrently.
Due to the unknown mechanism of deferiprone induced neutropenia, patients must not take medicinal products known to be associated with neutropenia or those that can cause agranulocytosis (see Contraindications).

Oral soln: Special precautions for disposal: No special requirements.
Incompatibilities: Not applicable.

Do not store above 30°C.
Oral soln: Shelf-Life: 3 years.
After first opening use within 35 days.

Antidotes & Detoxifying Agents

V03AC02 - deferiprone ; Belongs to the class of iron chelating agents. Used in iron overload.

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