Mechanism of Action
Olopatadine is an antihistamine with selective H1 -receptor antagonist activity: its principal effects are mediated via inhibition of H1 receptors. The antihistaminic activity of olopatadine has been documented in isolated tissues, animal models, and humans.
Pharmacodynamics
Cardiac effects: In a placebo-controlled cardiovascular safety study, 32 healthy volunteers received 20 mg oral solution of olopatadine twice daily for 14 days (8-fold greater daily dose than the recommended daily nasal dose). The mean QTcF (QT corrected by Fridericia's correction method for heart rate) change from baseline was -2.7 msec and -3.8 msec for olopatadine, and placebo, respectively. In this study, 8 subjects treated with olopatadine had a QTcF change from baseline of 30 - 60 msec, 1 subject had a QTcF change from baseline greater than 60 msec, and no subjects had QTcF values greater than 500 msec. Eight subjects treated with placebo had a QTcF change from baseline of 30 - 60 msec, no subjects had a QTcF change from baseline greater than 60 msec, and no subjects had QTcF values greater than 500 msec. In a 12-month study in 429 perennial allergic rhinitis patients treated with PATANASE Nasal Spray 2 sprays per nostril twice daily, no evidence of any effect of olopatadine hydrochloride on QT prolongation was observed.
Pharmacokinetics
The pharmacokinetic properties of olopatadine were studied after administration by the nasal, oral, intravenous, and topical ocular routes. Olopatadine exhibited linear pharmacokinetics across the routes studied over a large dose range.
Absorption
Healthy Subjects: Olopatadine was absorbed with individual peak
plasma concentrations observed between 30 minutes and 1 hour after twice daily
intranasal administration of PATANASE Nasal Spray. The mean steady-state peak
plasma concentration (Cmax) of olopatadine was 16.0 ± 8.99 ng/mL. Systemic
exposure as indexed by area under the curve (AUC0-12) averaged 66.0 ±
26.8 ng·h/mL. The average absolute bioavailability of intranasal olopatadine
is 57%. The mean accumulation ratio following multiple intranasal administration
of PATANASE Nasal Spray was about 1.3.
Seasonal Allergic Rhinitis (SAR) Patients: Systemic exposure
of olopatadine in SAR patients after twice daily intranasal administration of
PATANASE Nasal Spray was comparable to that observed in healthy subjects. Olopatadine
was absorbed with peak plasma concentrations observed between 15 minutes and
2 hours. The mean steady-state Cmax was 23.3 ± 6.2 ng/mL and AUC0-12
averaged 78.0 ± 13.9 ng·h/mL.
Distribution: The protein binding of olopatadine was moderate
at approximately 55% in human serum, and independent of drug concentration over
the range of 0.1 to 1000 ng/mL. Olopatadine was bound predominately to human
serum albumin.
Metabolism: Olopatadine is not extensively metabolized. Based
on plasma metabolite profiles following oral administration of [14C]
olopatadine, at least six minor metabolites circulate in human plasma. Olopatadine
accounts for 77% of peak plasma total radioactivity and all metabolites amounted
to < 6% combined. Two of these have been identified as the olopatadine N-oxide
and N-desmethyl olopatadine. In in vitro studies with cDNA-expressed
human cytochrome P450 isoenzymes (CYP) and flavin-containing monooxygenases
(FMO), N-desmethyl olopatadine (Ml) formation was catalyzed mainly by CYP3 A4,
while olopatadine N-oxide (M3) was primarily catalyzed by FMO1 and FMO3. Olopatadine
at concentrations up to 33,900 ng/mL did not inhibit the in vitro metabolism
of specific substrates for CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4.
The potential for olopatadine and its metabolites to act as inducers of CYP
enzymes has not been evaluated.
Elimination: The plasma elimination half-life of olopatadine
is 8 to 12 hours. Olopatadine is mainly eliminated through urinary excretion.
Approximately 70% of a [14C] olopatadine hydrochloride oral dose
was recovered in urine with 17% in the feces. Of the drug-related material recovered
within the first 24 hours in the urine, 86% was unchanged olopatadine with the
balance comprised of olopatadine N-oxide and N-desmethyl olopatadine.
Special Population
Hepatic Impairment: No specific pharmacokinetic study examining the
effect of hepatic impairment was conducted. Since metabolism of olopatadine
is a minor route of elimination, no adjustment of the dosing regimen of PATANASE
Nasal Spray is warranted in patients with hepatic impairment.
Renal Impairment: The mean Cmax values for olopatadine following single
intranasal doses were not markedly different between healthy subjects (18.1
ng/mL) and patients with mild, moderate and severe renal impairment (range 15.5
to 21.6 ng/mL). Mean plasma AUC0-12 was two-fold higher in patients with severe
impairment (creatinine clearance < 30 mL/min/1.73 m2). In these
patients, peak steady-state plasma concentrations of olopatadine are approximately
10-fold lower than those observed after higher 20 mg oral doses, twice daily,
which were safe and well-tolerated. These findings indicate that no adjustment
of the dosing regimen of PATANASE Nasal Spray is warranted in patients with
renal impairment.
Gender: The mean systemic exposure (Cmax and AUC0-12) in female SAR
patients following multiple administration of olopatadine was 40% and 27% higher,
respectively than those values observed in male SAR patients.
Race: The effects of race on olopatadine pharmacokinetics have not been
adequately investigated.
Age: The effects of age on olopatadine pharmacokinetics have not been
adequately investigated.
Nonclinical Toxicology
Animal Toxicology
Reproductive Toxicology Studies
Olopatadine was not teratogenic in rabbits and rats at oral doses of up to
400 or 600 mg/kg/day, respectively (approximately 1,400 and 1,000 times the
MRHD for adults on a mg/m2 basis, respectively). However, a decrease
in the number of live fetuses was observed in rabbits at the oral olopatadine
doses of 25 mg/kg (approximately 88 times the MRHD for adults on a mg/m2
basis) and above, and in rats at oral doses of 60 mg/kg (approximately 100 times
the MRHD for adults on a mg/m2 basis) and above. In rats, viability
and body weights of pups were reduced on day 4 post partum at the oral doses
of 60 mg/kg (approximately 100 times the MRHD for adults on a mg/m2
basis) and above, but no effect on viability was observed at the dose of 20
mg/kg (approximately 35 times the MRHD for adults on a mg/m2 basis).
Clinical Studies
Seasonal Allergic Rhinitis
Adult and Adolescent Patients 12 Years of Age and Older
The efficacy and safety of PATANASE Nasal Spray were evaluated in three randomized, double blind, parallel group, multicenter, placebo (vehicle nasal spray)-controlled clinical trials of 2 weeks duration in adult and adolescent patients, 12 years of age and older with symptoms of seasonal allergic rhinitis. The three clinical trials were conducted in the United States and included 1,598 patients (556 males, and 1,042 females) 12 years of age and older. In these three trials 587 patients were treated with PATANASE Nasal Spray 0.6%, 418 patients were treated with PATANASE Nasal Spray 0.4%, and 593 patients were treated with vehicle nasal spray. Assessment of efficacy was based on patient recording of 4 individual nasal symptoms (nasal congestion, rhinorrhea, itchy nose, and sneezing) on a 0 to 3 categorical severity scale (0 = absent, 1 = mild, 2 = moderate, 3 = severe) as reflective or instantaneous scores. Reflective scoring required patients to record symptom severity over the previous 12 hours; the instantaneous scoring required patients to record symptom severity at the time of recording. The primary efficacy endpoint was the difference from placebo in the percent change from baseline in the sum of morning and evening reflective total nasal symptom score (rTNSS) averaged for the 2-week treatment period. In all 3 trials, patients treated with PATANASE Nasal Spray, two sprays per nostril, twice-daily, exhibited statistically significantly greater decreases in rTNSS compared to vehicle nasal spray. Results for the rTNSS from two representative trials are shown in Table 2.
Table 2: Mean Reflective Total Nasal Symptom Score (rTNSS)
Over 2 Weeks in Seasonal Allergic Rhinitis Trials
| |
Treatment |
N |
Baseline |
Change from Baseline |
Difference from Placebo |
| |
|
|
|
|
Estimate |
95% CI |
p-value |
| Study 1 |
PATANASE Nasal Spray 0.6% |
183 |
8.71 |
-3.63 |
-0.96 |
(-1.42, -0.51) |
< 0.0001 |
| |
PATANASE Nasal Spray 0.4% |
188 |
8.90 |
-3.38 |
-0.71 |
(-1.17, -0.26) |
0.0023 |
| |
Vehicle Nasal Spray |
191 |
8.75 |
-2.67 |
|
|
|
| Study 2 |
PATANASE Nasal Spray 0.6% |
220 |
9.17 |
-2.90 |
-0.98 |
(-1.37, -0.59) |
< 0.0001 |
| |
PATANASE Nasal Spray 0.4% |
228 |
9.26 |
-2.63 |
-0.72 |
(-1.11, -0.33) |
0.0003 |
| |
Vehicle Nasal Spray |
223 |
9.07 |
-1.92 |
|
|
|
In the 2-week seasonal allergic trials, onset of action was also evaluated by instantaneous TNSS assessments twice- daily after the first dose of study medication. In these trials, onset of action was seen after 1 day of dosing. Onset of action was evaluated in three environmental exposure unit studies with single doses of PATANASE Nasal Spray. In these studies, patients with seasonal allergic rhinitis were exposed to high levels of pollen in the environmental exposure unit and then treated with either PATANASE Nasal Spray or vehicle nasal spray, two sprays in each nostril, after which they self-reported their allergy symptoms hourly as instantaneous scores for the subsequent 12 hours. PATANASE Nasal Spray 0.6% was found to have an onset of action of 30 minutes after dosing in the environmental exposure unit.
Last updated on RxList: 5/14/2008