AZELASTINE HYDROCHLORIDE AND FLUTICASONE PROPIONATE Dailymed

7 Drug Interactions

No formal drug interaction studies have been performed with azelastine hydrochloride and fluticasone propionate nasal spray. The drug interactions of the combination are expected to reflect those of the individual components.

• •Potent inhibitors of cytochrome P450 (CYP) 3A4: May increase blood levels of fluticasone propionate.
• •Ritonavir: Coadministration is not recommended. (5.6, 7.2)
• •Other potent CYP3A4 inhibitors, such as ketoconazole: use caution with coadministration. (5.6, 7.2)

7.1 Central Nervous System Depressants

Concurrent use of azelastine hydrochloride and fluticasone propionate nasal spray with alcohol or other central nervous system depressants should be avoided because somnolence and impairment of central nervous system performance may occur [see Warnings and Precautions (5.1)].

7.2 Cytochrome P450 3A4

Ritonavir (a strong CYP3A4 inhibitor) significantly increased plasma fluticasone propionate exposure following administration of fluticasone propionate aqueous nasal spray, resulting in significantly reduced serum cortisol concentrations [see Clinical Pharmacology (12.3)]. During postmarketing use, there have been reports of clinically significant drug interactions in patients receiving fluticasone propionate and ritonavir, resulting in systemic corticosteroid effects including Cushing syndrome and adrenal suppression. Therefore, coadministration of fluticasone propionate and ritonavir is not recommended unless the potential benefit to the patient outweighs the risk of systemic corticosteroid side effects.

Ketoconazole (also a strong CYP3A4 inhibitor), administered in multiple 200 mg doses to steady-state, increased plasma exposure of fluticasone propionate, reduced plasma cortisol AUC, but had no effect on urinary excretion of cortisol, following administration of a single 1000 mcg dose of fluticasone propionate by oral inhalation route.

Caution should be exercised when azelastine hydrochloride and fluticasone propionate nasal spray is coadministered with ketoconazole and other known strong CYP3A4 inhibitors.

8 Use In Specific Populations

8.1 Pregnancy

Risk Summary

Limited data from postmarketing experience with azelastine hydrochloride and fluticasone propionate nasal spray in pregnant women have not identified any drug associated risks of miscarriage, birth defects, or other adverse maternal or fetal outcomes. The individual components of azelastine hydrochloride and fluticasone propionate nasal spray have been marketed for decades. While the data regarding the use of nasal preparations of fluticasone propionate in pregnancy are limited, data from clinical studies of inhaled fluticasone propionate do not indicate an increased risk of adverse maternal or fetal outcomes.

Animal reproduction studies with azelastine hydrochloride and fluticasone propionate nasal spray are not available; however, studies are available with its individual components, azelastine hydrochloride and fluticasone propionate. In animal reproduction studies, there was no evidence of fetal harm in animals at oral doses of azelastine hydrochloride approximately 10 times the clinical daily dose. Oral administration of azelastine hydrochloride to pregnant mice, rats, and rabbits, during the period of organogenesis, produced developmental toxicity that included structural abnormalities, decreased embryo-fetal survival, and decreased fetal body weights at doses 530 times and higher than the maximum recommended human daily nasal dose (MRHDID) of 0.548 mg. However, the relevance of these findings in animals to pregnant women was considered questionable based upon the high animal to human dose multiple.

In animal reproduction studies, fluticasone propionate administered via nose-only inhalation to rats decreased fetal body weight, but did not induce teratogenicity at a maternal toxic dose less than the MRHDID on a mcg/m² basis. Teratogenicity, characteristic of corticosteroids, decreased fetal body weight and/or skeletal variations, in rats, mice, and rabbits were observed with subcutaneously administered maternal toxic doses of fluticasone propionate less than the MRHDID of 200 mcg on a mcg/m² basis (see Data). Experience with corticosteroids suggests that rodents are more prone to teratogenic effects from corticosteroids than humans.

The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively.

Data

Animal Data: Azelastine Hydrochloride: In an embryo-fetal development study in mice dosed during the period of organogenesis, azelastine hydrochloride caused embryo-fetal death, structural abnormalities (cleft palate; short or absent tail; fused, absent or branched ribs), delayed ossification, and decreased fetal weight at approximately 610 times the MRHDID in adults (on a mg/m² basis at a maternal oral dose of 68.6 mg/kg/day), which also caused maternal toxicity as evidenced by decreased maternal body weight. Neither fetal nor maternal effects occurred in mice at approximately 25 times the MRHDID in adults (on a mg/m² basis at a maternal oral dose of 3 mg/kg/day).

In an embryo-fetal development study in pregnant rats dosed during the period of organogenesis from gestation days 7 to 17, azelastine hydrochloride caused structural abnormalities (oligo-and brachydactylia), delayed ossification, and skeletal variations, in the absence of maternal toxicity, at approximately 530 times the MRHDID in adults (on a mg/m² basis at a maternal oral dose of 30 mg/kg/day). Azelastine hydrochloride caused embryo-fetal death and decreased fetal weight and severe maternal toxicity at approximately 1200 times the MRHDID (on a mg/m² basis at a maternal oral dose of 68.6 mg/kg/day). Neither fetal nor maternal effects occurred at approximately 55 times the MRHDID (on a mg/m² basis at a maternal oral dose of 3 mg/kg/day).

In an embryo-fetal development study in pregnant rabbits dosed during the period of organogenesis from gestation days 6 to 18, azelastine hydrochloride caused abortion, delayed ossification and decreased fetal weight and severe maternal toxicity at approximately 1100 times the MRHDID in adults (on a mg/m² basis at a maternal oral dose of 30 mg/kg/day). Neither fetal nor maternal effects occurred at approximately 10 times the MRHDID (on a mg/m² basis at a maternal oral dose of 0.3 mg/kg/day).

In a prenatal and postnatal development study in pregnant rats dosed from late in the gestation period and through the lactation period from gestation day 17 through lactation day 21, azelastine hydrochloride produced no adverse developmental effects on pups at maternal doses up to approximately 530 times the MRHDID (on mg/m² basis at a maternal dose of 30 mg/kg/day).

Fluticasone Propionate: In embryofetal development studies with pregnant rats and mice dosed by the subcutaneous route throughout the period of organogenesis, fluticasone propionate was teratogenic in both species. Omphalocele, decreased body weight, and skeletal variations were observed in rat fetuses, in the presence of maternal toxicity, at a dose approximately 5 times the MRHDID (on a mg/m² basis with a maternal subcutaneous dose of 100 mcg/kg/day). Neither fetal nor maternal effects occurred in rats at approximately 1 times the MRHDID (on a mg/m² basis with a maternal subcutaneous dose of 30 mcg/kg/day). Cleft palate and fetal skeletal variations were observed in mouse fetuses at a dose approximately 1 times the MRHDID (on a mg/m² basis with a maternal subcutaneous dose of 45 mcg/kg/day). Neither fetal nor maternal effects occurred in mice with a dose approximately 0.4 times the MRHDID (on a mg/m² basis with a maternal subcutaneous dose of 15 mcg/kg/day).

In an embryofetal development study with pregnant rats dosed by the nose-only inhalation route throughout the period of organogenesis, fluticasone propionate produced decreased fetal body weights and skeletal variations, in the presence of maternal toxicity, at a dose approximately 1 times the MRHDID (on a mg/m² basis with a maternal nose-only inhalation dose of 25.7 mcg/kg/day); however, there was no evidence of teratogenicity. Neither fetal nor maternal effects occurred in rats with a dose approximately 0.25 times the MRHDID (on a mg/m² basis with a maternal nose-only inhalation dose of 5.5 mcg/kg/day).

In an embryofetal development study in pregnant rabbits that were dosed by the subcutaneous route throughout organogenesis, fluticasone propionate produced reductions of fetal body weights, in the presence of maternal toxicity, at doses approximately 0.06 times the MRHDID and higher (on a mg/m² basis with a maternal subcutaneous dose of 0.57 mcg/kg/day). Teratogenicity was evident based upon a finding of cleft palate for 1 fetus at dose approximately 0.4 times the MRHDID (on a mg/m² basis with a maternal subcutaneous dose of 4 mcg/kg/day). Neither fetal nor maternal effects occurred in rabbits with a dose approximately 0.01 times the MRHDID (on a mg/m² basis with a maternal subcutaneous dose of 0.08 mcg/kg/day).

Fluticasone propionate crossed the placenta following subcutaneous administration to mice and rats and oral administration to rabbits.

In a pre-and post-natal development study in pregnant rats dosed from late gestation through delivery and lactation (Gestation Day 17 to Postpartum Day 22), fluticasone propionate was not associated with decreases in pup body weight, and had no effects on developmental landmarks, learning, memory, reflexes, or fertility at doses up to 2 times the MRHDID (on a mg/m² basis with maternal subcutaneous doses up to 50 mcg/kg/day).

8.2 Lactation

Risk Summary

There are no available data on the presence of azelastine hydrochloride or fluticasone propionate in human milk, the effects on the breastfed infant, or the effects on milk production. Breastfed infants should be monitored for signs of milk rejection during azelastine hydrochloride and fluticasone propionate nasal spray use by lactating women (see Clinical Considerations). Fluticasone propionate is present in rat milk (see Data). Other corticosteroids have been detected in human milk. However, fluticasone propionate concentrations in plasma after nasal therapeutic doses are low and therefore concentrations in human breast milk are likely to be correspondingly low [see Clinical Pharmacology (12.3)]. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for azelastine hydrochloride and fluticasone propionate nasal spray and any potential adverse effects on the breastfed infant from azelastine hydrochloride and fluticasone propionate nasal spray or from the underlying maternal condition.

Clinical Considerations

Monitoring for Adverse Reactions: Breastfed infants of lactating women treated with azelastine hydrochloride and fluticasone propionate nasal spray should be monitored for possible signs of milk rejection related to the bitter taste of azelastine hydrochloride.

Data

Subcutaneous administration of 10 mcg/kg of tritiated fluticasone propionate to lactating rats resulted in measurable radioactivity in the milk.

8.4 Pediatric Use

The safety and effectiveness of azelastine hydrochloride and fluticasone propionate nasal spray for seasonal allergic rhinitis have been established in pediatric patients aged 6 years and older. Use of azelastine hydrochloride and fluticasone propionate nasal spray for this indication in pediatric patients 6 to 11 years of age is supported by evidence from controlled clinical trials (416 patients 6 to 11 years of age with allergic rhinitis were treated with azelastine hydrochloride and fluticasone propionate nasal spray) [see Adverse Reactions (6.1) and Clinical Studies (14)].

Sixty-one patients ages 4-5 years of age were treated with azelastine hydrochloride and fluticasone propionate nasal spray in the pediatric studies described above. Safety findings in children 4-5 years of age were similar to those in children 6-11 years of age, but effectiveness has not been established.

Safety and effectiveness of azelastine hydrochloride and fluticasone propionate nasal spray have not been established in pediatric patients below the age of 4 years.

Controlled clinical studies have shown that nasal corticosteroids may cause a reduction in growth velocity in pediatric patients. This effect has been observed in the absence of laboratory evidence of HPA axis suppression, suggesting that growth velocity is a more sensitive indicator of systemic corticosteroid exposure in pediatric patients than some commonly used tests of HPA axis function. The long-term effects of this reduction in growth velocity associated with nasal corticosteroids, including the impact on final adult height, are unknown. The potential for “catch-up” growth following discontinuation of treatment with nasal corticosteroids has not been adequately studied. The growth of pediatric patients receiving nasal corticosteroids, including azelastine hydrochloride and fluticasone propionate nasal spray, should be monitored routinely (e.g., via stadiometry). The potential growth effects of prolonged treatment should be weighed against the clinical benefits obtained and the risks/benefits of treatment alternatives.

8.5 Geriatric Use

Clinical trials of azelastine hydrochloride and fluticasone propionate nasal spray did not include sufficient numbers of patients 65 years of age and older to determine whether they respond differently from younger patients. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

Azelastine hydrochloride and fluticasone propionate nasal spray is formulated as a white, uniform metered-spray suspension for nasal administration. It is a fixed dose combination product containing an antihistamine (H₁ receptor antagonist) and a corticosteroid as active ingredients.

Azelastine hydrochloride active ingredient occurs as a white, odorless, crystalline powder with a bitter taste. It has a molecular weight of 418.37. It is sparingly soluble in water, methanol, and propylene glycol and slightly soluble in ethanol, octanol, and glycerin. It has a melting point of 225°C and the pH of 5.2. Its chemical name is (±)- 1-(2H)-phthalazinone,4-[(4-chlorophenyl) methyl]-2-(hexahydro-1-methyl-1H-azepin-4-yl)-, monohydrochloride. Its molecular formula is C₂₂H₂₄ClN₃O•HCl with the following chemical structure:



Fluticasone propionate active ingredient is a white powder with a melting point of 273°C, a molecular weight of 500.6, and the empirical formula is C ₂₅ H ₃₁ F ₃ O ₅ S. It is practically insoluble in water, freely soluble in dimethyl sulfoxide and dimethylformamide, and slightly soluble in methanol and 95% ethanol. Fluticasone propionate is a synthetic corticosteroid having the chemical name S-(fluoromethyl)-6α,9-difluoro-11β-17-dihydroxy-16α -methyl-3-oxoandrosta -1,4-diene-17β-carbothioate, 17-propionate, and the following chemical structure:



Azelastine hydrochloride and fluticasone propionate nasal spray, 137 mcg/50 mcg contains 0.1% solution of azelastine hydrochloride and 0.037% suspension of micronized fluticasone propionate in an isotonic aqueous suspension containing glycerin, microcrystalline cellulose and carboxymethylcellulose sodium, phenylethyl alcohol (2.5 mg/g), edetate disodium, benzalkonium chloride (0.1 mg/g), polysorbate 80, and purified water. It has a pH of approximately 6.0.

After priming [see Dosage and Administration (2.2)], each metered spray delivers a 0.137 mL mean volume of suspension containing 137 mcg of azelastine hydrochloride (equivalent to 125 mcg of azelastine base) and 50 mcg of fluticasone propionate. The 23 g bottle provides 120 metered sprays, after priming.

12 Clinical Pharmacology

12.1 Mechanism of Action

Azelastine hydrochloride and fluticasone propionate nasal spray: Azelastine hydrochloride and fluticasone propionate nasal spray contains both azelastine hydrochloride and fluticasone propionate; therefore, the mechanisms of actions described below for the individual components apply to azelastine hydrochloride and fluticasone propionate nasal spray. These drugs represent two different classes of medications (histamine H₁-receptor antagonist and synthetic corticosteroid).

Azelastine Hydrochloride: Azelastine hydrochloride, a phthalazinone derivative, exhibits histamine H₁-receptor antagonist activity in isolated tissues, animal models, and humans. Azelastine hydrochloride in azelastine hydrochloride and fluticasone propionate nasal spray is administered as a racemic mixture with no difference in pharmacologic activity noted between the enantiomers in in vitro studies. The major metabolite, desmethylazelastine, also possesses H₁-receptor antagonist activity.

Fluticasone Propionate: Fluticasone propionate is a synthetic trifluorinated corticosteroid with anti-inflammatory activity. In vitro dose response studies on a cloned human glucocorticoid receptor system involving binding and gene expression afforded 50% responses at 1.25 and 0.17 nM concentrations, respectively. Fluticasone propionate was 3-fold to 5-fold more potent than dexamethasone in these assays. Data from the McKenzie vasoconstrictor assay in man also support its potent glucocorticoid activity. The clinical relevance of these findings is unknown.

The precise mechanism through which fluticasone propionate affects allergic rhinitis symptoms is not known. Corticosteroids have been shown to have a wide range of effects on multiple cell types (e.g., mast cells, eosinophils, neutrophils, macrophages, and lymphocytes) and mediators (e.g., histamine, eicosanoids, leukotrienes, and cytokines) involved in inflammation.

12.2 Pharmacodynamics

Cardiac Electrophysiology:

In a placebo-controlled trial (95 patients with allergic rhinitis), there was no evidence of an effect of azelastine hydrochloride nasal spray (2 sprays per nostril twice daily for 56 days) on cardiac repolarization as represented by the corrected QT interval (QTc) of the electrocardiogram. Following multiple dose oral administration of azelastine 4 mg or 8 mg twice daily, the mean change in QTc was 7.2 msec and 3.6 msec, respectively.

Interaction studies investigating the cardiac repolarization effects of concomitantly administered oral azelastine hydrochloride and erythromycin or ketoconazole were conducted. These drugs had no effect on QTc based on analysis of serial electrocardiograms.

12.3 Pharmacokinetics

Absorption: After nasal administration of two sprays per nostril (548 mcg of azelastine hydrochloride and 200 mcg of fluticasone) of azelastine hydrochloride and fluticasone propionate nasal spray, the mean (± standard deviation) peak plasma exposure (C_max) was 194.5 ± 74.4 pg/mL for azelastine and 10.3±3.9 pg/mL for fluticasone propionate and the mean total exposure (AUC) was 4217 ± 2618 pg/mL*hr for azelastine and 97.7 ± 43.1 pg/mL*hr for fluticasone. The median time to peak exposure (t_max) from a single dose was 0.5 hours for azelastine and 1.0 hours for fluticasone.

Systemic bioavailability of azelastine from azelastine hydrochloride and fluticasone propionate nasal spray following nasal administration was comparable with monotherapy azelastine hydrochloride nasal spray without sweetener (i.e., approximately 40%). Systemic bioavailability of fluticasone from azelastine hydrochloride and fluticasone propionate nasal spray following nasal administration was 44-61% higher than monotherapy fluticasone propionate (bioavailability for monotherapy fluticasone nasal spray was less than 2%). Due to the low nasal bioavailability, pharmacokinetic data for fluticasone propionate were obtained via other routes of administration. Studies using oral dosing of radiolabeled fluticasone propionate showed negligible oral bioavailability and high extraction from plasma. The majority of the circulating radioactivity was due to an inactive metabolite.

Distribution: Based on intravenous and oral administration, the steady-state volume of distribution of azelastine hydrochloride is 14.5 L/kg. In vitro studies with human plasma indicate that the plasma protein binding of azelastine hydrochloride and its metabolite, desmethylazelastine, are approximately 88% and 97%, respectively.

Following intravenous administration, the initial disposition phase for fluticasone propionate was rapid and consistent with its high lipid solubility and tissue binding. The volume of distribution averaged 4.2 L/kg.

The percentage of fluticasone propionate bound to human plasma proteins averaged 91% with no obvious concentration relationship. Fluticasone propionate is weakly and reversibly bound to erythrocytes and freely equilibrates between erythrocytes and plasma. Fluticasone propionate is not significantly bound to human transcortin.

Elimination: Following nasal administration of azelastine hydrochloride and fluticasone propionate nasal spray, the elimination half-life of azelastine hydrochloride is approximately 25 hours. Approximately 75% of an oral dose of radiolabeled azelastine hydrochloride was excreted in the feces with less than 10% as unchanged azelastine.

Following intravenous dosing, fluticasone propionate showed polyexponential kinetics and had a terminal elimination half-life of approximately 7.8 hours. Less than 5% of a radiolabeled oral dose was excreted in the urine as metabolites, with the remainder excreted in the feces as parent drug and metabolites.

Metabolism: Azelastine hydrochloride is oxidatively metabolized to the principal active metabolite, desmethylazelastine, by the cytochrome P450 enzyme system. The specific P450 isoforms responsible for the biotransformation of azelastine have not been identified. The total clearance of azelastine is approximately 0.50 L/kg/hr.

For fluticasone propionate, the only circulating metabolite detected in man is the 17β-carboxylic acid derivative, which is formed through the CYP3A4 pathway. This inactive metabolite had less affinity (approximately 1/2,000) than the parent drug for the glucocorticoid receptor of human lung cytosol in vitro and negligible pharmacological activity in animal studies. Other metabolites detected in vitro using cultured human hepatoma cells have not been detected in man. The average total clearance of fluticasone propionate is relatively high (approximately 66 L/hr).

Specific Populations: Azelastine hydrochloride and fluticasone propionate nasal spray was not studied in any specific populations, and no gender-specific pharmacokinetic data have been obtained.

Following oral administration of azelastine hydrochloride, pharmacokinetic parameters were not influenced by hepatic

impairment, age, or gender. The effect of race has not been evaluated.

Patients with Renal Impairment: Based on oral, single-dose studies of azelastine hydrochloride, renal impairment (creatinine clearance <50 mL/min) resulted in a 70-75% higher C_max and AUC compared to healthy subjects. Time to maximum concentration was unchanged.

Drug Interaction Studies: No formal drug interaction studies have been performed with azelastine hydrochloride and fluticasone propionate nasal spray. The drug interactions of the combination are expected to reflect those of the individual components.

Erythromycin: Coadministration of orally administered azelastine (4 mg twice daily) with erythromycin (500 mg three times daily for 7 days) resulted in C_max of 5.36 ± 2.6 ng/mL and AUC of 49.7 ± 24 ng•h/mL for azelastine, whereas, administration of azelastine alone resulted in C_max of 5.57 ± 2.7 ng/mL and AUC of 48.4 ± 24 ng•h/mL for azelastine.

In another multiple-dose drug interaction study, coadministration of orally inhaled fluticasone propionate (500 mcg twice daily) and erythromycin (333 mg three times daily) did not affect fluticasone propionate pharmacokinetics.

Cimetidine and Ranitidine: In a multiple-dose, steady-state drug interaction trial in healthy subjects, cimetidine (400 mg twice daily) increased orally administered mean azelastine hydrochloride (4 mg twice daily) concentrations by approximately 65%. Coadministration of orally administered azelastine hydrochloride (4 mg twice daily) with ranitidine hydrochloride (150 mg twice daily) resulted in C_max of 8.89 ± 3.28 ng/mL and AUC of 88.22 ± 40.43 ng•h/mL for azelastine hydrochloride, whereas, administration of azelastine hydrochloride alone resulted in C_max of 7.83 ± 4.06 ng/mL and AUC of 80.09 ± 43.55 ng•h/mL for azelastine hydrochloride.

Theophylline: No significant pharmacokinetic interaction was observed with the coadministration of an oral 4 mg dose of azelastine hydrochloride twice daily and theophylline 300 mg or 400 mg twice daily.

Ritonavir: Coadministration of fluticasone propionate and the strong CYP3A4 inhibitor, ritonavir, is not recommended based upon a multiple-dose, crossover drug interaction study in 18 healthy subjects. Fluticasone propionate aqueous nasal spray (200 mcg once daily) was coadministered for 7 days with ritonavir (100 mg twice daily). Plasma fluticasone propionate concentrations following fluticasone propionate aqueous nasal spray alone were undetectable (<10 pg/mL) in most subjects, and when concentrations were detectable, peak levels (C_max) averaged 11.9 pg/mL (range, 10.8 to 14.1 pg/mL) and AUC(0-τ) averaged 8.43 pg•hr/mL (range, 4.2 to 18.8 pg•hr/mL). Fluticasone propionate C_max and AUC(0-τ) increased to 318 pg/mL (range, 110 to 648 pg/mL) and 3,102.6 pg•hr/mL (range, 1,207.1 to 5,662.0 pg•hr/mL), respectively, after coadministration of ritonavir with fluticasone propionate aqueous nasal spray. This significant increase in plasma fluticasone propionate exposure resulted in a significant decrease (86%) in plasma cortisol area under the plasma concentration versus time curve (AUC).

Caution should be exercised when other strong CYP3A4 inhibitors are coadministered with fluticasone propionate. In a drug interaction study, coadministration of orally inhaled fluticasone propionate (1,000 mcg) and ketoconazole (200 mg once daily) resulted in increased fluticasone propionate exposure and reduced plasma cortisol AUC, but had no effect on urinary excretion of cortisol [see Drug Interactions (7.2)].