CLINICAL PHARMACOLOGY
Mechanism Of Action
Azelastine hydrochloride, a phthalazinone derivative, exhibits histamine H1 -receptor antagonist activity
in isolated tissues, animal models, and humans. Azelastine HCl nasal solution (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.
Pharmacodynamics
Cardiac Effects
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. Oral erythromycin had no
effect on azelastine pharmacokinetics or QTc based on analysis of serial electrocardiograms.
Ketoconazole interfered with the measurement of azelastine plasma levels; however, no effects on QTc
were observed [see DRUG INTERACTIONS].
Pharmacokinetics
Absorption
After intranasal administration of 2 sprays per nostril (548 mcg total dose) of azelastine HCl
nasal solution (nasal spray), 0.1%, the mean azelastine peak plasma concentration (Cmax) is 200 pg/mL,
the mean extent of systemic exposure (AUC) is 5122 pg•hr/mL and the median time to reach Cmax (tmax
is 3 hours. After intranasal administration of 2 sprays per nostril (822 mcg total dose) of azelastine HCl
nasal solution (nasal spray), 0.15%, the mean azelastine peak plasma concentration (Cmax) is 409 pg/mL,
the mean extent of systemic exposure (AUC) is 9312 pg•hr/mL and the median time to reach Cmax (tmax )
is 4 hours. The systemic bioavailability of azelastine hydrochloride is approximately 40% after
intranasal administration.
Distribution
Based on intravenous and oral administration, the steady-state volume of distribution of
azelastine 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 a single-dose, intranasal
administration of azelastine HCl nasal solution (nasal spray), 0.1% (548 mcg total dose), the mean
desmethylazelastine Cmax is 23 pg/mL, the AUC is 2131 pg•hr/mL and the median tmax is 24 hours.
After a single-dose, intranasal administration of azelastine HCl nasal solution (nasal spray), 0.15% (822
mcg total dose), the mean desmethylazelastine Cmax is 38 pg/mL, the AUC is 3824 pg•hr/mL and the
median tmax is 24 hours. After intranasal dosing of azelastine to steady-state, plasma concentrations of
desmethylazelastine range from 20-50% of azelastine concentrations.
Elimination
Following intranasal administration of azelastine HCl nasal solution (nasal spray), 0.1%, the
elimination half-life of azelastine is 22 hours while that of desmethylazelastine is 52 hours. Following
intranasal administration of azelastine HCl nasal solution (nasal spray), 0.15%, the elimination half-life
of azelastine is 25 hours while that of desmethylazelastine is 57 hours. 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 70-75% higher Cmax and AUC compared to healthy 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
Co-administration of orally administered azelastine (4 mg twice daily) with erythromycin
(500 mg three times daily for 7 days) 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 [see DRUG INTERACTIONS].
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%. Co-administration of orally administered azelastine (4 mg twice
daily) with ranitidine hydrochloride (150 mg twice daily) resulted in Cmax of 8.89 ±3.28 ng/mL and
AUC of 88.22 ± 40.43 ng•h/mL for azelastine, whereas, administration of azelastine alone resulted in
Cmax of 7.83 ± 4.06 ng/mL and AUC of 80.09 ± 43.55 ng•h/mL for azelastine [see DRUG INTERACTIONS].
Theophylline
No significant pharmacokinetic interaction was observed with the co-administration of an
oral 4 mg dose of azelastine hydrochloride twice daily and theophylline 300 mg or 400 mg twice daily.
Clinical Studies
Seasonal Allergic Rhinitis
AzelastineHCl Nasal Solution (Nasal Spray), 0.1%
The efficacy and safety of azelastine HCl nasal solution (nasal spray), 0.1% was evaluated in a 2-week,
randomized, multicenter, double-blind, placebo-controlled clinical trial including 834 adult and
adolescent patients 12 years of age and older with symptoms of seasonal allergic rhinitis. The
population was 12 to 83 years of age (60% female, 40% male; 69% white, 16% black, 12% Hispanic,
2% Asian, 1% other).
Patients were randomized to one of six treatment groups: 1 spray per nostril of either azelastine HCl
nasal solution (nasal spray), 0.1%, azelastine HCl nasal solution (nasal spray) without sweetener or
vehicle placebo twice daily; or 2 sprays per nostril of azelastine HCl nasal solution (nasal spray), 0.1%,
azelastine HCl nasal solution (nasal spray) without sweetener or vehicle placebo twice daily.
Assessment of efficacy was based on the 12-hour reflective total nasal symptom score (rTNSS)
assessed daily in the morning and evening, in addition to the instantaneous total nasal symptom score
(iTNSS) and other supportive secondary efficacy variables. TNSS is calculated as the sum of the
patients’ scoring of the four individual nasal symptoms (rhinorrhea, nasal congestion, sneezing, and
nasal itching) on a 0 to 3 categorical severity scale (0 = absent, 1 = mild, 2 = moderate, 3 = severe). The
rTNSS required patients to record symptom severity over the previous 12 hours. For the primary
efficacy endpoint, the mean change from baseline rTNSS, morning (AM) and evening (PM) rTNSS
scores were summed for each day (maximum score of 24) and then averaged over the 2 weeks. The
iTNSS, recorded immediately prior to the next dose, were assessed as an indication of whether the
effect was maintained over the dosing interval.
In this trial, azelastine HCl nasal solution (nasal spray), 0.1% two sprays twice a day demonstrated a
greater decrease in rTNSS and iTNSS than placebo and the difference was statistically significant.
The trial results are presented in Table 3 (Trial 1).
The efficacy of azelastine HCl nasal solution (nasal spray), 0.1% one spray per nostril twice daily for
seasonal allergic rhinitis is supported by two, 2-week, placebo-controlled clinical trials with azelastine
HCl nasal solution (nasal spray) without sweetener in 413 patients with seasonal allergic rhinitis. In
these trials, efficacy was assessed using the TNSS (described above). Azelastine HCl nasal solution
(nasal spray) without sweetener demonstrated a greater decrease from baseline in the summed AM and
PM rTNSS compared with placebo and the difference was statistically significant.
AzelastineHCl Nasal Solution (Nasal Spray), 0.15%
The efficacy and safety of azelastine HCl nasal solution (nasal spray), 0.15% in seasonal allergic
rhinitis was evaluated in five randomized, multicenter, double-blind, placebo-controlled clinical trials in
2499 adult and adolescent patients 12 years and older with symptoms of seasonal allergic rhinitis
(Trials 2, 3, 4, 5, and 6). The population of the trials was 12 to 83 years of age (64% female, 36% male;
81% white, 12% black, <2% Asian, 5% other; 23% Hispanic, 77% non-Hispanic). Assessment of
efficacy was based on the rTNSS, iTNSS as described above, and other supportive secondary efficacy
variables. The primary efficacy endpoint was the mean change from baseline in rTNSS over 2 weeks.
Two 2-week seasonal allergic rhinitis trials evaluated the efficacy of azelastine HCl nasal solution
(nasal spray), 0.15% dosed at 2 sprays twice daily. The first trial (Trial 2) compared the efficacy of
azelastine HCl nasal solution (nasal spray), 0.15% and azelastine HCl nasal solution (nasal spray)
without sweetener to vehicle placebo. The other trial (Trial 3) compared the efficacy of azelastine HCl
nasal solution (nasal spray), 0.15% and azelastine HCl nasal solution (nasal spray), 0.1% to vehicle
placebo. In these two trials, azelastine HCl nasal solution (nasal spray), 0.15% demonstrated greater
decreases in rTNSS than placebo and the differences were statistically significant (Table 3).
Three 2-week seasonal allergic rhinitis trials evaluated the efficacy of azelastine HCl nasal solution
(nasal spray), 0.15% dosed at 2 sprays once daily compared to the vehicle placebo. Trial 4
demonstrated a greater decrease in rTNSS than placebo and the difference was statistically significant
(Table 3). Trial 5 and Trial 6 were conducted in patients with Texas mountain cedar allergy. In Trial 5
and Trial 6, azelastine HCl nasal solution (nasal spray), 0.15% demonstrated a greater decrease in
rTNSS than placebo and the differences were statistically significant (Trials 5 and 6; Table 3).
Instantaneous TNSS results for the once daily dosing regimen of azelastine HCl nasal solution (nasal
spray), 0.15% are shown in Table 4. In Trials 5 and 6, azelastine HCl nasal solution (nasal spray), 0.15%
demonstrated a greater decrease in iTNSS than placebo and the differences were statistically
significant.
Table 3: Mean Change from Baseline in Reflective TNSS over 2 Weeks* in Adults and Children ≥ 12 years with Seasonal Allergic Rhinitis
|
Treatment (sprays per month) |
n |
Baseline LS Mean |
Change from Baseline |
Difference From Placebo |
LS Mean |
95% CI |
P value |
Trial 1 |
Two sprays twice daily |
Azelastine HCl nasal solution (nasal spary), 0.1% |
146 |
18.0 |
-5.0 |
-2.2 |
-3.2, -1.2 |
<0.001 |
Azelastine HCl nasal solution (nasal spary), without sweetener |
137 |
18.2 |
-4.2 |
-1.4 |
-2.4, -0.4 |
0.01 |
Vehicle Placebo |
138 |
18.2 |
-2.8 |
|
One sprays twice daily |
Azelastine HCl nasal solution (nasal spary), 0.1% |
139 |
18.2 |
-4.2 |
-0.7 |
-1.7, 0.3 |
0.18 |
Azelastine HCl nasal solution (nasal spary), without sweetener |
137 |
18.1 |
-4.0 |
-0.4 |
-1.5, 0.6 |
0.41 |
Vehicle Placebo |
137 |
18.0 |
-3.5 |
|
Trial 2 |
Two sprays twice daily |
Azelastine HCl nasal solution (nasal spary), 0.15% |
153 |
18.2 |
-4.3 |
-1.2 |
-2.1, -0.3 |
0.01 |
Azelastine HCl nasal solution (nasal spary), without sweetener |
153 |
17.9 |
-3.9 |
-0.9 |
-1.8, 0.1 |
0.07 |
Vehicle Placebo |
153 |
18.1 |
-3.0 |
|
Trial 3 |
Two sprays twice daily |
Azelastine HCl nasal solution (nasal spary), 0.15% |
177 |
17.7 |
-5.1 |
-3.0 |
-3.9, -2.1 |
<0.001 |
Azelastine HCl nasal solution (nasal spary), 0.1% |
169 |
18.2 |
-4.2 |
-2.1 |
-3.0, -1.2 |
<0.001 |
Vehicle Placebo |
177 |
17.7 |
-2.1 |
|
Trial 4 |
Two sprays once daily |
Azelastine HCl nasal solution (nasal spary), 0.15% |
238 |
17.4 |
-3.4 |
-1.0 |
-1.7, -0.3 |
0.008 |
Vehicle Placebo |
242 |
17.4 |
-2.4 |
|
Trial 5 |
Two sprays once daily |
Azelastine HCl nasal solution (nasal spary), 0.15% |
266 |
18.5 |
-3.3 |
-1.0 |
-2.1, -0.8 |
<0.001 |
Vehicle Placebo |
266 |
18.0 |
-1.9 |
|
Trial 6 |
Two sprays once daily |
Azelastine HCl nasal solution (nasal spary), 0.15% |
251 |
18.5 |
-3.3 |
-1.4 |
-2.1, -0.8 |
<0.001 |
Vehicle Placebo |
254 |
18.8 |
-2.0 |
|
*Sum of AM and PM rTNSS for each day (Maximum score =24) and averaged over the 14 day treatment period |
Table 4: Mean Change from Baseline AM Instantaneous TNSS over 2 Weeks* in Adults and Children ≥ 12 years with Seasonal Allergic Rhinitis
|
Treatment (sprays per nostril once daily) |
n |
Baseline LS Mean |
Change from Baseline |
Difference From Placebo |
LS Mean |
95% CI |
P value |
Trial 4 |
Two sprays once daily |
Azelastine HCl nasal solution (nasal spary), 0.15% |
238 |
8.1 |
-1.3 |
-0.2 |
-0.6, 0.1 |
0.15 |
Vehicle Placebo |
242 |
8.3 |
-1.1 |
|
Trial 5 |
Two sprays once daily |
Azelastine HCl nasal solution (nasal spary), 0.15% |
266 |
8.7 |
-1.4 |
-0.7 |
-1.0, -0.4 |
<0.001 |
Vehicle Placebo |
266 |
8.3 |
-0.7 |
|
Trial 6 |
Two sprays once daily |
Azelastine HCl nasal solution (nasal spary), 0.15% |
251 |
8.9 |
-1.4 |
-0.6 |
-0.9, -0.3 |
<0.001 |
Vehicle Placebo |
254 |
8.9 |
-0.8 |
|
*AM iTNSS for each day (Maximum score =12) and averaged over the 14 day treatment period |
Azelastine HCl nasal solution (nasal spray), 0.15% at a dose of 1 spray twice daily was not studied. The
azelastine HCl nasal solution (nasal spray), 0.15% 1 spray twice daily dosing regimen is supported by
previous findings of efficacy for azelastine HCl nasal solution (nasal spray) without sweetener and a
favorable comparison of azelastine HCl nasal solution (nasal spray), 0.15% to azelastine HCl nasal
solution (nasal spray) without sweetener and azelastine HCl nasal solution (nasal spray), 0.1% (Table 3).
Pediatric use information for patients ages 6 to 11 years of age for treatment of allergic rhinitis, including
seasonal and perennial allergic rhinitis is approved for Meda Pharmaceuticals’ azelastine hydrochloride
nasal spray product. However, due to Meda Pharmaceuticals’ marketing exclusivity rights, this drug product
is not labeled with that pediatric information.
Perennial Allergic Rhinitis
AzelastineHCl Nasal Solution (Nasal Spray), 0.15%
The efficacy and safety of azelastine HCl nasal solution (nasal spray), 0.15% in perennial allergic
rhinitis was evaluated in one randomized, multicenter, double-blind, placebo-controlled clinical trial in
578 adult and adolescent patients 12 years and older with symptoms of perennial allergic rhinitis. The
population of the trial was 12 to 84 years of age (68% female, 32% male; 85% white, 11% black, 1%
Asian, 3% other; 17% Hispanic, 83% non-Hispanic).
Assessment of efficacy was based on the 12-hour reflective total nasal symptom score (rTNSS)
assessed daily in the morning and evening, the instantaneous total nasal symptom score (iTNSS), and
other supportive secondary efficacy variables. The primary efficacy endpoint was the mean change
from baseline rTNSS over 4 weeks. The one 4-week perennial allergic rhinitis trial evaluated the
efficacy of azelastine HCl nasal solution (nasal spray), 0.15%, azelastine HCl nasal solution (nasal
spray), 0.1%, and vehicle placebo dosed at 2 sprays per nostril twice daily. In this trial, azelastine HCl
nasal solution (nasal spray), 0.15% demonstrated a greater decrease in rTNSS than placebo and the
difference was statistically significant (Table 5).
Table 4: Mean Change from Baseline in Reflective TNSS over 4 Weeks* in Adults and Children ≥ 12 years with Perennial Allergic Rhinitis
|
Treatment (sprays per nostril twice daily) |
n |
Baseline LS Mean |
Change from Baseline |
Difference From Placebo |
LS Mean |
95% CI |
P value |
Two sprays once daily |
Azelastine HCl nasal solution (nasal spary), 0.15% |
192 |
15.8 |
-4.0 |
-0.9 |
-1.7, -0.1 |
0.03 |
Azelastine HCl nasal solution (nasal spary), 0.1% |
194 |
15.5 |
-3.8 |
-0.7 |
-1.5, 0.1 |
0.08 |
Vehicle Placebo |
192 |
14.7 |
-3.1 |
|
|
|
*Sum of AM and PM rTNSS for each day (Maximum score =24) and averaged over the 28 day treatment period |
Pediatric use information for patients ages 6 to 11 years of age for treatment of allergic rhinitis, including
seasonal and perennial allergic rhinitis is approved for Meda Pharmaceuticals’ azelastine hydrochloride
nasal spray product. However, due to Meda Pharmaceuticals’ marketing exclusivity rights, this drug product
is not labeled with that pediatric information.