Deflazacort 22.75 Mg/ml Oral Suspension

Shake deflazacort oral suspension well before administration.

Use only the oral dispenser provided with the product. After withdrawing the appropriate dose into the oral dispenser, slowly add the deflazacort oral suspension into 3 to 4 ounces of juice (except grapefruit juice) or milk and mix well. The dose should then be administered immediately.

Discard any unused deflazacort oral suspension remaining after 1 month of first opening the bottle.

Give one third of the recommended dosage when deflazacort oral suspension is administered with moderate or strong CYP3A4 inhibitors. For example, a 36 mg per day dose would be reduced to a 12 mg per day dose when used with moderate or strong CYP3A4 inhibitors [see Drug Interactions (7.1) and Clinical Pharmacology (12.3)].

CYP3A4 Inducers

Avoid use with moderate or strong CYP3A4 inducers with deflazacort oral suspension [see Drug Interactions (7.1) and Clinical Pharmacology (12.3)].

Risk of Adrenal Insufficiency Following Corticosteroid Withdrawal

Corticosteroids produce reversible hypothalamic-pituitary-adrenal (HPA) axis suppression, with the potential for the development of secondary adrenal insufficiency after withdrawal of corticosteroid treatment. Acute adrenal insufficiency can occur if corticosteroids are withdrawn abruptly, and can be fatal. The degree and duration of adrenocortical insufficiency produced is variable among patients and depends on the dose, frequency, and duration of corticosteroid therapy. The risk is reduced by gradually tapering the corticosteroid dose when withdrawing treatment. This insufficiency may persist, however, for months after discontinuation of prolonged therapy; therefore, in any situation of stress occurring during that period of discontinuation, corticosteroid therapy should be reinstituted. For patients already taking corticosteroids during times of stress, the dosage may need to be increased.

A steroid "withdrawal syndrome", seemingly unrelated to adrenocortical insufficiency, may also occur following abrupt discontinuance of corticosteroids. This syndrome includes symptoms such as anorexia, nausea, vomiting, lethargy, headache, fever, joint pain, desquamation, myalgia, and/or weight loss. These effects are thought to be due to the sudden change in corticosteroid concentration rather than to low corticosteroid levels.

Cushing's Syndrome

Cushing's syndrome (hypercortisolism) occurs with prolonged exposure to exogenous corticosteroids, including deflazacort. Symptoms include hypertension, truncal obesity and thinning of the limbs, purple striae, facial rounding, facial plethora, muscle weakness, easy and frequent bruising with thin fragile skin, posterior neck fat deposition, osteopenia, acne, amenorrhea, hirsutism and psychiatric abnormalities.

Hyperglycemia

Corticosteroids can increase blood glucose, worsen pre-existing diabetes, predispose those on long-term therapy to diabetes mellitus, and may reduce the effect of anti-diabetic drugs.

Monitor blood glucose at regular intervals. For patients with hyperglycemia, anti-diabetic treatment should be initiated or adjusted accordingly.

Considerations for Use in Patients with Altered Thyroid Function

Metabolic clearance of corticosteroids is decreased in hypothyroid patients and increased in hyperthyroid patients. Changes in thyroid status of the patient may necessitate a dose adjustment of the corticosteroid. When concomitant administration of corticosteroids and levothyroxine is required, administration of corticosteroid should precede the initiation of levothyroxine therapy to reduce the risk of adrenal crisis.

Pheochromocytoma Crisis

There have been reports of pheochromocytoma crisis, which can be fatal, after administration of systemic corticosteroids. In patients with suspected or identified pheochromocytoma, consider the risk of pheochromocytoma crisis prior to administering corticosteroids.

Dietary salt restriction and potassium supplementation may be necessary. Deflazacort should be used with caution in patients with congestive heart failure, hypertension, or renal insufficiency.

Literature reports suggest an association between use of corticosteroids and left ventricular free wall rupture after a recent myocardial infarction; therefore, therapy with deflazacort should be used with great caution in these patients.

Avoid corticosteroids if there is a probability of impending perforation, abscess, or other pyogenic infections; diverticulitis; fresh intestinal anastomoses; or active or latent peptic ulcer.

Corticosteroids, including deflazacort, decrease bone formation and increase bone resorption both through their effect on calcium regulation (i.e., decreasing absorption and increasing excretion) and inhibition of osteoblast function. This, together with a decrease in the protein matrix of the bone secondary to an increase in protein catabolism and reduced sex hormone production, may lead to inhibition of bone growth in pediatric patients and the development of bone loss at any age. Bone loss can predispose patients to vertebral and long bone fractures. Consider a patient's risk of osteoporosis before initiating corticosteroid therapy.

Monitor bone mineral density in patients on long-term treatment with deflazacort.

Avascular Necrosis

Corticosteroids, including deflazacort, may cause avascular necrosis.

Corticosteroids are not recommended for patients with active ocular herpes simplex.

Intraocular pressure may become elevated in some patients taking corticosteroids. If treatment with deflazacort is continued for more than 6 weeks, monitor intraocular pressure.

When prescribing deflazacort oral suspension, consider the combined daily metabolic load of benzyl alcohol from all sources, including deflazacort oral suspension (deflazacort oral suspension contains 10.45 mg of benzyl alcohol per mL) and other drugs containing benzyl alcohol. The minimum amount of benzyl alcohol at which serious adverse reactions may occur is not known. At the recommended dose of 0.9 mg/kg/day of deflazacort oral suspension, patients would receive approximately 0.4 mg/kg/day of benzyl alcohol [see Use in Specific Populations (8.4)].

The active metabolite of deflazacort, 21-desDFZ, is a substrate of CYP3A4 [see Clinical Pharmacology (12.3)]. Co-administration of deflazacort with clarithromycin, a strong CYP3A4 inhibitor, increased total exposure to 21-desDFZ by about 3-fold. Therefore, give one third the recommended dosage of deflazacort when moderate or strong CYP3A4 inhibitors (e.g., clarithromycin, fluconazole, diltiazem, verapamil, grapefruit juice) are used concomitantly with deflazacort [see Dosage and Administration (2.5) and Clinical Pharmacology (12.3)].

Moderate or Strong CYP3A4 Inducers

Co-administration of deflazacort with rifampin, a strong CYP3A4 inducer, significantly decreased the exposure of 21-desDFZ. Avoid concomitant use of strong (e.g., efavirenz) or moderate (e.g., carbamazepine, phenytoin) CYP3A4 inducers with deflazacort [see Dosage and Administration (2.5) and Clinical Pharmacology (12.3)].

Corticosteroids should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Infants born to mothers who have received substantial doses of corticosteroids during pregnancy should be carefully observed for signs of hypoadrenalism. There are no adequate and well-controlled studies with deflazacort in pregnant women to inform drug-associated risks.

Corticosteroids, including deflazacort, readily cross the placenta. Adverse developmental outcomes, including orofacial clefts (cleft lip, with or without cleft palate) and intrauterine growth restriction, and decreased birth weight, have been reported with maternal use of corticosteroids, including deflazacort, during pregnancy. Some epidemiologic studies report an increased risk of orofacial clefts from about 1 per 1,000 infants to 3 to 5 per 1,000 infants; however, a risk for orofacial clefts has not been observed in all studies. Intrauterine growth restriction and decreased birth weight appear to be dose-related; however, the underlying maternal condition may also contribute to these risks (see Data). The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Animal reproduction studies have not been conducted with deflazacort. Animal reproduction studies conducted with other corticosteroids in pregnant mice, rats, hamsters, and rabbits using clinically relevant doses have shown an increased incidence of cleft palate. An increase in embryofetal death, intrauterine growth retardation, and constriction of the ductus arteriosus were observed in some animal species.

Data

Human Data

Multiple cohort and case-controlled studies in humans suggest that maternal corticosteroid use during the first trimester increases the rate of cleft lip, with or without cleft palate, from about 1/1,000 infants to 3 to 5/1,000 infants. Two prospective case-controlled studies showed decreased birth weight in infants exposed to maternal corticosteroids in utero.

Systemically administered corticosteroids appear in human milk and could suppress growth, interfere with endogenous corticosteroid production, or cause other untoward effects. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for deflazacort and any potential adverse effects on the breastfed infant from deflazacort. There are no data on the effects on milk production.

Safety and effectiveness in pediatric patients below the age of 2 years have not been established.

Deflazacort oral suspension contains benzyl alcohol and is not approved for use in pediatric patients less than 2 years of age. Serious adverse reactions including fatal reactions and "gasping syndrome" occurred in premature neonates and low birth weight infants in the neonatal intensive care unit who received drugs containing benzyl alcohol as a preservative. In these cases, benzyl alcohol dosages of 99 mg/kg/day to 234 mg/kg/day produced high levels of benzyl alcohol and its metabolites in the blood and urine (blood levels of benzyl alcohol were 0.61 mmol/L to 1.378 mmol/L). Additional adverse reactions included gradual neurological deterioration, seizures, intracranial hemorrhage, hematologic abnormalities, skin breakdown, hepatic and renal failure, hypotension, bradycardia, and cardiovascular collapse. Preterm, low-birth weight infants may be more likely to develop these reactions because they may be less able to metabolize benzyl alcohol.

When prescribing deflazacort oral suspension consider the combined daily metabolic load of benzyl alcohol from all sources including deflazacort oral suspension (deflazacort oral suspension contains 10.45 mg of benzyl alcohol per mL) and other drugs containing benzyl alcohol. The minimum amount of benzyl alcohol at which serious adverse reactions may occur is not known. At the recommended dose of 0.9 mg/kg/day of deflazacort oral suspension, patients would receive approximately 0.4 mg/kg/day of benzyl alcohol [see Warnings and Precautions (5.13)].

Juvenile Animal Toxicity Data

Oral administration of deflazacort (0, 0.1, 0.3, and 1 mg/kg/day) to juvenile rats from postnatal day (PND) 21 to 80 resulted in decreased body weight gain and adverse effects on skeletal development (including decreased cellularity of growth plate and altered bone distribution) and on lymphoid tissue (decreased cellularity). A no-effect dose was not identified. In addition, neurological and neurobehavioral abnormalities were observed at the mid and/or high dose.

Plasma 21-desDFZ exposure (AUC) at the lowest dose tested (0.1 mg/kg/day) was lower than that in humans at the recommended human dose of deflazacort (0.9 mg/kg/day).

Additional pediatric use information is approved for PTC Therapeutics, Inc.'s Emflaza™ (deflazacort) oral suspension. However, due to PTC Therapeutics, Inc.'s marketing exclusivity rights, this drug product is not labeled with that information.

After oral administration in the fasted state, the median T_max with deflazacort suspension is about 1 hour (range 0.25 to 2 hours).

Food Effect: Co-administration of deflazacort tablets with a high-fat meal reduced C_max by about 30% and delayed T_max by one hour, relative to administration under fasting conditions, but there was no effect on the overall systemic absorption as measured by AUC. The bioavailability of deflazacort tablets was similar to that of the oral suspension. The administration of deflazacort with food or crushed in applesauce did not affect the absorption and bioavailability of deflazacort.

Distribution

The protein binding of the active metabolite of deflazacort is about 40%.

Elimination

Metabolism

Deflazacort is rapidly converted to the active metabolite 21-desDFZ by esterases after oral administration. 21-desDFZ is further metabolized by CYP3A4 to several other inactive metabolites, including 6β-hydroxy-21-desacetyl deflazacort.

Excretion

Urinary excretion is the predominant route of deflazacort elimination (about 68% of the dose), and the elimination is almost completed by 24 hours post dose. 21-desDFZ accounts for 18% of the eliminated drug in the urine.

Specific Populations

Pediatric Patients

The C_max values (Geometric mean, %CV) of 21-desDFZ in children (ages 4 to 11, N=16) and adolescents (ages 12 to 16, N=8) was 206 ng/mL (95.6%) and 381 ng/mL (37.7%), respectively, on Day 1 after administration of 0.9 mg/kg deflazacort. The AUC_inf (Geometric mean, %CV) of 21-desDFZ in children (ages 4 to 11, N=16) and adolescents (ages 12 to 16, N=8) was 400 ng•h/mL (87.5%) and 655 ng•h/mL (58.1%) on Day 1 after administration of 0.9 mg/kg deflazacort.

Male and Female Patients

There are no differences in the pharmacokinetics of 21-desDFZ between males and females.

Racial or Ethnic Groups

There are no differences in the pharmacokinetics of 21-desDFZ between Caucasians and non-Caucasians.

Patients with Renal Impairment

In a study (N=16) comparing subjects with end stage renal disease (creatinine clearance less than 15 mL/min) with healthy matched controls, 21-desDFZ exposure was similar between the groups.

Patients with Hepatic Impairment

In a study (N=16) comparing subjects with moderate hepatic impairment (Child-Pugh Class B) with healthy matched controls, 21-desDFZ exposure was similar between the groups. There is no experience in patients with severe hepatic impairment.

Drug Interaction Studies

In Vivo Assessment of Drug Interactions

Compared to administration of deflazacort alone, administration of deflazacort following multiple doses of a strong CYP3A4 and Pgp inhibitor (clarithromycin) resulted in markedly higher C_max, AUC_last, and AUC_inf values of 21-desDFZ. Geometric mean exposure (C_max, AUC_last, and AUC_inf) of 21-desDFZ ranged from 2.3-fold to 3.4-fold higher following administration of clarithromycin [see Dosage and Administration (2.5)].

Compared to administration of deflazacort alone, administration of deflazacort following multiple doses of a strong CYP3A4 inducer (rifampicin) resulted in markedly lower C_max, AUC_last, and AUC_inf values of 21-desDFZ. Geometric mean exposures (C_max, AUC_last, and AUC_inf) of 21-desDFZ were approximately 95% lower following administration of rifampin [see Drug Interactions (7.1)].

6β-Hydroxy-21-desacetyl deflazacort, a secondary and inactive metabolite, is not expected to cause any clinically meaningful interactions with the CYP enzymes or transporters.

In Vitro Assessment of Drug Interactions

Drug-Metabolizing Enzyme Inhibition

21-desDFZ at clinically relevant concentrations did not inhibit CYP1A2, 2C9, 2C19, 3A4, UGT1A1, UGT1A4, UGT1A6, UGT1A9, or UGT2B7 and exhibited weak and not likely clinically meaningful inhibition for 2B6, 2C8, 2D6, and 3A4, UGT1A3 and UGT2B15.

6β-Hydroxy-21-desacetyl deflazacort at clinically relevant concentrations did not significantly inhibit CYP2C19, 3A4 1A2, 2B6, 2C8, 2C9, or 2D6.

Drug-Metabolizing Enzyme Induction

21-desDFZ and 6β-hydroxy-21-desacetyl deflazacort at clinically relevant concentrations did not significantly induce CYP1A2, 2B6, or 3A4.

Transporters

Both deflazacort and 21-desDFZ are substrates of Pgp. 21-desDFZ is not a substrate for BCRP. Neither deflazacort nor 21-desDFZ inhibited Pgp or BCRP in vitro. 21-desDFZ was not a substrate for SLC transporters OATP1B1 or OATP1B3, and did not inhibit SLC transporters OATP1B1, OATP1B3, OAT1, OAT3, or OCT2.

6β-Hydroxy-21-desacetyl deflazacort at clinically relevant concentrations did not significantly inhibit BCRP, OAT1, OAT3, Pgp, OATP1B1, OATP1B3 MATE1, MATE2-K, OCT1, OCT2, or BSEP transporters.

In a published 2-year carcinogenicity study in rats, oral administration of deflazacort (0, 0.03, 0.06, 0.12, 0.25, 0.50, or 1 mg/kg/day) resulted in bone tumors (osteosarcoma and osteoma) of the head at 0.25 mg/kg/day, the highest evaluable dose. Doses higher than 0.25 mg/kg/day could not be evaluated for tumors because of a marked decrease in survival.

In a 6-month carcinogenicity study in transgenic (Tg.RasH2) mice, oral administration of deflazacort (0, 2, 5, or 20 mg/kg/day in males; 0, 0.5, 2, or 5 mg/kg/day in females) resulted in an increase in stomach tumors (adenoma) at the highest dose tested in males and females.

Mutagenesis

Deflazacort and 21-desDFZ were negative in in vitro (bacterial reverse mutation and human lymphocyte chromosomal aberration) assays and deflazacort was negative in an in vivo (rat micronucleus) assay.

Impairment of Fertility

Fertility studies in animals were not conducted with deflazacort. No effects on the male reproductive system were observed following oral administration of deflazacort to monkeys (0, 1, 3, or 6 mg/kg/day) for 39 weeks or rats (0, 0.05, 0.15, or 0.5 mg/kg/day) for 26 weeks. Plasma 21-desDFZ exposures (AUC) at the highest doses tested in monkey and rat were 4 and 2 times, respectively, that in humans at the recommended human dose of deflazacort (0.9 mg/kg/day).

Discard any unused deflazacort oral suspension remaining after 1 month of first opening the bottle.