2.1 Seasonal Allergic Rhinitis

The recommended dosage of azelastine hydrochloride nasal solution in adults and adolescent patients 12 years and older with seasonal allergic rhinitis is one or two sprays per nostril twice daily. The recommended dosage of azelastine hydrochloride nasal solution in pediatric patients 5 years to 11 years of age is one spray per nostril twice daily.

2.2 Vasomotor Rhinitis

The recommended dosage of azelastine hydrochloride nasal solution in adults and adolescent patients 12 years and older with vasomotor rhinitis is two sprays per nostril twice daily.

2.3 Important Administration Instructions

Administer azelastine hydrochloride nasal solution by the intranasal route only.

Priming: Prime azelastine hydrochloride nasal solution before initial use by releasing 4 sprays or until a fine mist appears. When azelastine hydrochloride nasal solution has not been used for 3 or more days, reprime with 2 sprays or until a fine mist appears. Avoid spraying azelastine hydrochloride nasal solution into the eyes.

5.1 Somnolence in Activities Requiring Mental Alertness

In clinical trials, the occurrence of somnolence has been reported in some patients taking azelastine hydrochloride nasal solution [see Adverse Reactions (6.1)]. Patients should be cautioned against engaging in hazardous occupations requiring complete mental alertness and motor coordination such as operating machinery or driving a motor vehicle after administration of azelastine hydrochloride nasal solution. Concurrent use of azelastine hydrochloride nasal solution with alcohol or other central nervous system depressants should be avoided because additional reductions in alertness and additional impairment of central nervous system performance may occur [see Drug Interactions (7.1)].

6.1 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect rates observed in practice.

Seasonal Allergic Rhinitis

Azelastine Hydrochloride Nasal Solution Two Sprays Per Nostril Twice Daily

Adverse experience information for azelastine hydrochloride nasal solution is derived from six placebo- and active- controlled, 2-day to 8-week clinical trials which included 391 patients, 12 years of age and older, with seasonal allergic rhinitis who received azelastine hydrochloride nasal solution at a dose of 2 sprays per nostril twice daily. In placebo-controlled efficacy trials, the incidence of discontinuation due to adverse reactions in patients receiving azelastine hydrochloride nasal solution and vehicle placebo was 2.2% and 2.8%, respectively.

Table 1 contains adverse reactions that were reported with frequencies ≥2% in the azelastine hydrochloride nasal solution 2 sprays per nostril twice daily treatment group and more frequently than placebo.

Azelastine Hydrochloride Nasal Solution One Spray Per Nostril Twice Daily

Adverse experience information for azelastine hydrochloride nasal solution at a dose of one spray per nostril twice daily is derived from two placebo-controlled 2-week clinical studies which included 276 patients 12 years of age and older with seasonal allergic rhinitis. The incidence of discontinuation due to adverse reactions in patients receiving azelastine hydrochloride nasal solution and vehicle placebo was 0% and 0.8%, respectively. Bitter taste was reported in 8.3% of patients compared to none in the placebo group. Somnolence was reported in 0.4% of patients compared to none in the placebo group.

A total of 176 patients 5 to 11 years of age were exposed to azelastine hydrochloride nasal solution at a dose of 1 spray each nostril twice daily in 3 placebo-controlled studies. In these studies, adverse reactions that occurred more frequently in patients treated with azelastine hydrochloride nasal solution than with placebo, and that were not represented in the adult adverse reactions table above include rhinitis/cold symptoms (17% vs. 9.5%), cough (11.4% vs. 8.3%), conjunctivitis (5.1% vs. 1.8%), and asthma (4.5% vs. 4.1%).

Adverse Reactions <2% in Azelastine Hydrochloride Nasal Solution One or Two Sprays Per Nostril Twice Daily

The following reactions were observed infrequently (<2% and exceeding placebo incidence) in patients who received azelastine hydrochloride nasal solution dosed at 1 or 2 sprays per nostril twice daily in U.S. clinical trials.

Cardiovascular: flushing, hypertension, tachycardia.

Dermatological: contact dermatitis, eczema, hair and follicle infection, furunculosis, skin laceration.

Digestive: constipation, gastroenteritis, glossitis, ulcerative stomatitis, vomiting, increased SGPT, aphthous stomatitis, diarrhea, toothache.

Metabolic and Nutritional: increased appetite.

Musculoskeletal: myalgia, temporomandibular dislocation, rheumatoid arthritis.

Neurological: hyperkinesia, hypoesthesia, vertigo.

Psychological: anxiety, depersonalization, depression, nervousness, sleep disorder, thinking abnormal.

Respiratory: bronchospasm, coughing, throat burning, laryngitis, bronchitis, dry throat, nocturnal dyspnea, nasopharyngitis, nasal congestion, pharyngolaryngeal pain, sinusitis, nasal dryness, paranasal sinus hypersecretion, post nasal drip.

Special Senses: conjunctivitis, eye abnormality, eye pain, watery eyes, taste loss.

Urogenital: albuminuria, amenorrhea, breast pain, hematuria, increased urinary frequency.

Whole Body: allergic reaction, back pain, herpes simplex, viral infection, malaise, pain in extremities, abdominal pain, pyrexia.

Vasomotor Rhinitis
Adverse experience information for azelastine hydrochloride nasal solution is derived from two placebo-controlled clinical studies which included 216 patients 12 years and older with vasomotor rhinitis who received azelastine hydrochloride nasal solution at a dose of 2 sprays per nostril twice daily for up to 28 days. The incidence of discontinuation due to adverse reactions in patients receiving azelastine hydrochloride nasal solution and vehicle placebo was 2.8% and 2.9%, respectively.

The following adverse reactions were reported with frequencies ≥ 2% in the azelastine hydrochloride nasal solution treatment group and more frequently than placebo.

Reactions observed infrequently (<2% and exceeding placebo incidence) in patients who received azelastine hydrochloride nasal solution (2 sprays/nostril twice daily) in U.S. clinical trials in vasomotor rhinitis were similar to those observed in U.S. clinical trials in seasonal allergic rhinitis.

In controlled trials involving nasal and oral azelastine hydrochloride formulations, there were infrequent occurrences of hepatic transaminase elevations.

6.2 Postmarketing Experience

During the post approval use of azelastine hydrochloride nasal solution, the following adverse reactions have been identified. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Adverse reactions reported include: anaphylaxis, application site irritation, atrial fibrillation, chest pain, confusion, dyspnea, facial edema, involuntary muscle contractions, nasal sores, palpitations, paresthesia, parosmia, pruritus, rash, disturbance or loss of sense of smell and/or taste, tolerance, urinary retention, vision abnormal and xerophthalmia.

7.1 Central Nervous System Depressants

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

8.1 Pregnancy

Risk Summary

Limited data from postmarketing experience over decades of use with azelastine hydrochloride nasal solution in pregnant women have not identified any drug associated risks of miscarriage, birth defects, or other adverse maternal or fetal outcomes. In animal reproduction studies, there was no evidence of fetal harm at oral doses approximately 5 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 270 times and higher than the maximum recommended human daily intranasal dose (MRHDID) of 1.096 mg. However, the relevance of these findings in animals to pregnant women was considered questionable based upon the high animal to human dose multiple.

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

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 300 times the maximum recommended human daily intranasal dose (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 15 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 270 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 610 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 20 times the MRHDID (on a mg/m2 basis at a maternal oral dose of 2 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 530 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 5 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 270 times the MRHDID (on mg/m2 basis at a maternal dose of 30 mg/kg/day).

8.2 Lactation

Risk Summary

There are no data on the presence of azelastine hydrochloride 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 nasal solution use by lactating women (see Clinical Considerations). The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for azelastine hydrochloride nasal solution and any potential adverse effects on the breastfed infant from azelastine hydrochloride nasal solution or from the underlying maternal condition.

Clinical Considerations
Monitoring for Adverse Reactions
Breastfed infants of lactating women treated with azelastine hydrochloride nasal solution should be monitored for possible signs of milk rejection related to the bitter taste of azelastine hydrochloride.

8.4 Pediatric Use

The safety and effectiveness of azelastine hydrochloride nasal solution for the treatment of symptoms of seasonal allergic rhinitis have been established for patients 5 years and older [see Adverse Reactions (6.1) and Clinical Studies (14.1)]. The safety and effectiveness of azelastine hydrochloride nasal solution for the treatment of vasomotor rhinitis have been established for patients 12 years and older [see Adverse Reactions (6.1) and Clinical Studies (14.2)]. The safety and effectiveness of azelastine hydrochloride nasal solution in pediatric patients below the age of 5 years with seasonal allergic rhinitis and in pediatric patients below the age of 12 years with vasomotor rhinitis have not been established.

8.5 Geriatric Use

Clinical trials of azelastine hydrochloride nasal solution did not include sufficient numbers of patients aged 65 and over 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.

12.1 Mechanism of Action

Azelastine hydrochloride, a phthalazinone derivative, exhibits histamine H1-receptor antagonist activity in isolated tissues, animal models, and humans. Azelastine hydrochloride nasal solution 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.

12.2 Pharmacodynamics

Cardiac Electrophysiology:
In a placebo-controlled study (95 subjects with allergic rhinitis), there was no evidence of an effect of azelastine hydrochloride nasal solution (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. At a dose approximately 8 times the maximum recommended dose, azelastine hydrochloride does not prolong the QTc interval to any clinically relevant extent.

12.3 Pharmacokinetics

Absorption: After intranasal administration, the systemic bioavailability of azelastine hydrochloride is approximately 40%. Maximum plasma concentrations (Cmax) are achieved in 2 to 3 hours.

Azelastine hydrochloride administered intranasally at doses above two sprays per nostril twice daily for 29 days resulted in greater than proportional increases in Cmax and area under the curve (AUC) for azelastine.

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

Metabolism: Azelastine 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. After intranasal dosing of azelastine hydrochloride to steady-state, plasma concentrations of desmethylazelastine range from 20 to 50% of azelastine concentrations. Limited data indicate that the metabolite profile is similar when azelastine hydrochloride is administered via the intranasal or oral route.

Elimination: Based on intravenous and oral administration, the elimination half-life and plasma clearance are 22 hours and 0.5 L/h/kg, respectively. Approximately 75% of an oral dose of radiolabeled azelastine hydrochloride was excreted in the feces with less than 10% as unchanged azelastine.

Special Populations:

Hepatic Impairment: Following oral administration, pharmacokinetic parameters were not influenced by hepatic impairment.

Renal Impairment: Based on oral, single-dose studies, renal insufficiency (creatinine clearance <50 mL/min) resulted in a 70 to 75% higher Cmax and AUC compared to normal subjects. Time to maximum concentration was unchanged.

Age: Following oral administration, pharmacokinetic parameters were not influenced by age.

Gender: Following oral administration, pharmacokinetic parameters were not influenced by gender.

Race: The effect of race has not been evaluated.

Drug-Drug Interactions:

Erythromycin: No significant pharmacokinetic interaction was observed with the coadministration of orally administered azelastine (4 mg twice daily) with erythromycin (500 mg three times daily for 7 days). In this study, coadministration of orally administered azelastine with erythromycin resulted in Cmax 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 Cmax of 5.57 ± 2.7 ng/mL and AUC of 48.4 ± 24 ng•h/mL for azelastine.

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 (4 mg twice daily) concentrations by approximately 65%. No pharmacokinetic interaction was observed with coadministration of orally administered azelastine (4 mg twice daily) with ranitidine hydrochloride (150 mg twice daily). Oral coadministration of azelastine with ranitidine resulted in Cmax of 8.89 ±3.28 ng/mL and AUC of 88.22 ± 40.43 ng•h/mL for azelastine, whereas, azelastine when administered alone resulted in Cmax of 7.83 ± 4.06 ng/mL and AUC of 80.09 ± 43.55 ng•h/mL for azelastine.

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.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Two-year carcinogenicity studies in Crl:CD(SD)BR rats and NMRI mice were conducted to assess the carcinogenic potential of azelastine hydrochloride. No evidence of tumorigenicity was observed in rats at doses up to 30 mg/kg day (approximately 270 and 240 times the MRHDID for adults and children, respectively, on a mg/m2 basis). No evidence for tumorigenicity was observed in mice at doses up to 25 mg/kg (approximately 110 and 100 times the MRHDID for adults and children, respectively, on a mg/m2 basis).

Azelastine hydrochloride showed no genotoxic effects in the Ames test, DNA repair test, mouse lymphoma forward mutation assay, mouse micronucleus test, or chromosomal aberration test in rat bone marrow.

There were no effects on male or female fertility and reproductive performance in male and female rats at oral doses up to 30 mg/kg (approximately 270 times the MRHDID in adults on a mg/m2 basis). At 68.6 mg/kg (approximately 610 times the MRHDID on a mg/m2 basis), the duration of estrous cycles was prolonged and copulatory activity and the number of pregnancies were decreased. The numbers of corpora lutea and implantations were decreased; however, preimplantation loss was not increased.

14.1 Seasonal Allergic Rhinitis

Two Sprays Per Nostril Twice Daily
The efficacy and safety of azelastine hydrochloride nasal solution were evaluated in three placebo-controlled clinical trials of azelastine hydrochloride nasal solution including 322 patients with seasonal allergic rhinitis who received two sprays per nostril twice a day for up to 4 weeks. These trials included 55 pediatric patients ages 12 to 16 years. Assessment of efficacy was based on the 12-hour reflective Total Symptom Complex (TSC) and Major Symptom Complex (MSC). The MSC was calculated as the average of individual symptoms of nose blows, sneezes, runny nose/sniffles, itchy nose, and watery eyes as assessed by patients on a 0 to 5 categorical scale. Azelastine hydrochloride nasal solution two sprays per nostril twice daily demonstrated a greater decrease in the MSC than placebo (Table 3).

In dose-ranging trials, administration of azelastine hydrochloride nasal solution two sprays per nostril twice daily resulted in a statistically significant decrease in symptoms compared to saline placebo within 3 hours after initial dosing and persisted over the 12-hour dosing interval.

One Spray Per Nostril Twice Daily

The efficacy and safety of azelastine hydrochloride nasal solution were evaluated in two placebo-controlled clinical trials of azelastine hydrochloride nasal solution including 275 patients with seasonal allergic rhinitis who received one spray per nostril twice a day for up to 2 weeks. Assessment of efficacy was based on the 12­-hour reflective Total Nasal Symptom Score [rTNSS]. rTNSS is calculated as the sum of the patients scoring of four individual nasal symptoms (runny nose, sneezing, itchy nose, and nasal congestion) as assessed by patients on a 0 to 3 categorical scale. The primary efficacy endpoint was the change from Baseline to Day 14 in rTNSS. The mean change from baseline in rTNSS was greater in patients receiving azelastine hydrochloride nasal solution one spray per nostril twice daily than those receiving placebo (Table 4).

Two-week studies comparing the efficacy (and safety) of azelastine hydrochloride nasal solution two sprays per nostril twice daily versus one spray per nostril twice daily were not conducted.

14.2 Vasomotor Rhinitis

The efficacy and safety of azelastine hydrochloride nasal solution were evaluated in two placebo-controlled clinical trials of azelastine hydrochloride nasal solution including 216 patients with vasomotor rhinitis who received two sprays per nostril twice a day for up to 4 weeks. These patients had vasomotor rhinitis for at least one year, negative skin tests to indoor and outdoor aeroallergens, negative nasal smears for eosinophils, and negative sinus X-rays. Azelastine hydrochloride nasal solution demonstrated a significantly greater decrease in a symptom complex comprised of rhinorrhea, post nasal drip, nasal congestion, and sneezing compared to placebo.