NDAC December 14, 2007 1 Effectiveness and Safety of Phenylephrine as an OTC Oral Nasal Decongestant Michael L. Koenig, Ph.D. Michael L. Koenig, Ph.D. Division of Nonprescription Regulation Division of Nonprescription Regulation Development Development Office of Nonprescription Products Office of Nonprescription Products
46
Embed
NDAC December 14, 2007 1 Effectiveness and Safety of Phenylephrine as an OTC Oral Nasal Decongestant Michael L. Koenig, Ph.D. Division of Nonprescription.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
NDAC December 14, 20071
Effectiveness and Safety of Phenylephrine as an OTC Oral Nasal Decongestant
Michael L. Koenig, Ph.D. Michael L. Koenig, Ph.D. Division of Nonprescription Regulation Development Division of Nonprescription Regulation Development Office of Nonprescription ProductsOffice of Nonprescription Products
NDAC December 14, 20072
Overview
• Effectiveness– Studies Included in Current Review– Endpoints– Studies Demonstrating Statistically Significant
Effects
• Pharmacokinetics• Safety
– Cardiovascular Risks– Review of Studies– AERS Database
• Summary
NDAC December 14, 20073
Understanding the Handout
Study ANPR CP CHPA
Patient Condition
Effectiveness
↓ NAR Symptom Relief
10 mg 25 mg 10 mg
25 mg
Sterling-Winthrop ■ Healthy ■ ■
Eliz1 ■ Cold ■* ■*
Eliz2 ■ ■ ■ Cold ■* ■* ■* ■
Eliz3 ■ Cold ■* ■
Eliz4 ■ Cold ■* ■
Eliz5 ■ ■ ■ Cold ■* ■* ■ ■*
McLaurin et al. ■ Various4 ■ ■
Blanchard et al.1 ■
*Statistically significant effect
NDAC December 14, 20074
Studies Cited by the Panel
• 15 Studies (1959-1975)– Excluded (2)1
– Elizabeth Biochemical Labs (5)– Cintest (Hill Top) Labs (3)– Huntingdon Research Center (2)– Sterling-Winthrop Research Institute (1)– McLaurin et al., 1961 (1)– Bio-Evaluation, Inc. (Cohen, 1975) (1)
• Symptom scores– 15/19 studies (only endpoint in 2)
• Both endpoints used in the same study– 13 studies
NDAC December 14, 200711
Nasal Airway Resistance?
• Congestion (swelling of nasal mucosa) obstructs nasal cavity and increases resistance to air flow
• Decongestion decreases resistance by opening the airway.
www.entsolwash.com
NDAC December 14, 200712
Rhinomanometry
• Process used since 1894
• Widely used in 1960s and 1970s
• Used today– Eccles, Cardiff University, Wales– Schumacher, Univ. of Arizona, Tucson
“Measurement of air flow and pressure within the nose during respiration”
NDAC December 14, 200713
No Standardization
• Based on different methods– Sternstein and Schur, 1936; McLaurin, 1960– Anterior vs. posterior measurement
• Utilized different instruments– Butler-Ivy and modifications, Respiron
• Evaluation of NAR– Over different time courses (1 – 5 hours)– At different time intervals (15 min – 3 hours)– Different numbers of replicate measurements
at each time point
NDAC December 14, 200714
Symptom Scores
Degree of Congestion Score
Nose feels clear 0
Almost clear 1
Stuffy 2
Very stuffy 3
Completely blocked 4
Elizabeth, Huntingdon, and Cintest Studies
Ordinal Scale
5-point
NDAC December 14, 200715
Overview
• Effectiveness– Studies Included in Current Review– Endpoints– Studies Demonstrating Statistically Significant
Effects
• Pharmacokinetics• Safety
– Cardiovascular Risks– Review of Studies– Adverse Events
• Summary
NDAC December 14, 200716
Evidence of Effectiveness
Dose (mg)
No.
Studies
Statistically Significant
↓ NAR Symptom Relief
10 16 7/14 5/12
25 10 7/10 3/8
10 and 25 mg Doses
NDAC December 14, 200717
Studies Demonstrating Significant Effects (10 mg)
Study n Controls Onset
(h)
Last
Eff. TP*
↓ NAR Sympt.
Relief
Eliz 2 16 Placebo Eph 0.25 2/2 0.01 0.01
Eliz 5 10 Placebo 0.5 3/4 0.01 NS
Cin 1 16 Placebo PPA 1.5 3/4 0.05 0.05
BEI 25/100 Placebo 0.25 2/2 0.05 0.05
Cohen, 72 16 Placebo 0.5 2/2 0.01-0.05
0.05
Wyeth G1-A 8 Baseline 1 2.5/4.5 0.005 0.05
Wyeth 4010
(multi-site)
66 Placebo PPA 0.5 3/4 0.001-0.05**
NS
**Evaluated at only 1 of 6 sites (n = 12)*Last effective time point/observation period (h)
NDAC December 14, 200718
Studies Demonstrating Significant Effects (25 mg)
Study n Controls Onset
(h)
Last Eff. TP*
↓ NAR Sympt.
Relief
Eliz 1 12 Placebo Eph 0.5 2/2 0.01 0.01
Eliz 2 6 Placebo Eph 0.5 2/2 0.01-.05 NS
Eliz 3 9 Placebo PPA 0.5 3/4 0.05 NS
Eliz 4 9 Placebo Eph 0.75 3/4 0.01 NS
Eliz 5 9 Placebo 0.5 4/4 0.01 0.05
Cin 1 15 Placebo PPA 2 4/4 0.025-0.05
NS
Cohen 72 16 Placebo 0.25 2/2 0.01-0.05 0.05
*Last effective time point/observation period (h)
NDAC December 14, 200719
Overview
• Effectiveness– Studies Included in Current Review– Endpoints– Studies Demonstrating Statistically Significant
Effects
• Pharmacokinetics• Safety
– Cardiovascular Risks– Review of Studies– Adverse Events
• 26 unique cases assoc with oral single ingredient phenylephrine– Serious outcome: 4 cases
• 1 Death (suicide)– Cardio-respiratory arrest from ingestion of several drugs (i.e.
hydrocodone)• 3 Hospitalizations
– Hemorrhagic stroke in a 44yo female; limited information– Elevated BP in a 15yo male; attributed to nephritis– Paralysis, depressed LOC, dysarthria, etc. in a 13yo male; illicit drug
use suspected; unlikely single dose caused 6 day event
* Limitations of AERS: underreporting, variable quality of reports, causality of drug uncertain, and inaccurate numerator and no denominator
NDAC December 14, 200730
Adverse Event Reporting System (1969 – 10/3/07)
All 5 medication errors involved confusion between Sudafed (pseudoephedrine) and Sudafed PE (phenylephrine)– Both tablets are similar in appearance (small, round, red) and packaged
in foil bubble blisters perforated in units of two (even though the recommended adult dose for Sudafed PE is one 10 mg tablet)
– Mistakenly ingested 20 mg (2 tabs); 1 case reported HA and nausea
Conclusions:• Adverse event reports occurred with overdoses (50%)
and non-overdoses (31%); 19% did not report any dosing information
• Adverse events and ED visits have been reported following use of oral single ingredient phenylephrine
NDAC December 14, 200731
Overview
• Effectiveness– Studies Included in Current Review– Endpoints– Studies Demonstrating Statistically Significant
Effects
• Pharmacokinetics• Safety
– Cardiovascular risks– Review of Studies– AERS Database
• Pharmacokinetics– 38% bioavailability may be high– Cmax: 60 – 300 ng/ml (total PE)
• 100-fold lower for parent PE
– Tmax: 1 – 1.3 h (total PE)• 0.5 – 1.25 h (parent PE)
– Elimination: urine; t1/2: 2.1 – 3.4 h
NDAC December 14, 200734
Summary• Safety – Studies
– Inconsistent effects on systolic and diastolic blood pressure and pulse rate
– Majority of studies showed no effect– “Minor” or “moderate” adverse events with
most studies reporting none
• Safety – AERS database (1969 – 2007)
NDAC December 14, 200735
Acknowledgements
• Review Team– Michael L. Chasey– Mary S. Robinson– Debbie L. Lumpkins
• Administrative Support– Delores Pinkney– Walter Ellenberg
NDAC December 14, 200736
Additional Slides
Koenig
NDAC December 14, 200737
Panel Review - Effectiveness
• Objective (NAR) measurements– Corroborating symptom scores – 1 study
• Studies demonstrating decongestion• Onset 15 – 20 min• Maximum effect: 30 - 90 minutes• Duration 2 – 4 hours• 25 mg more effective than 10 mg
• Studies not demonstrating decongestion• Greater apparent placebo response• Variability in patient response
NDAC December 14, 200738
Panel Review - Safety
• Cited 12 studies– BP and pulse rate responses
• 10 and 15 mg doses: equal to placebo• 25 mg dose
– BP: occasional ↑ up to 7 mm Hg– Pulse rate: occasional changes of ± 4-13 beats/min
– Adverse events• 10 mg dose: placebo• 15 and 25 mg: symptoms associated with mild
CNS stimulation
NDAC December 14, 200739
SP P04579
• 2006• Primary objective: PE vs. placebo• R, investigator-blind, placebo and active (PSE) controls,
3-way crossover, single-dose• 3 treatment visits; 5-day washout• n = 38 with 2-y history of SAR due to grass pollen• Congestion induced by 6 h pollen exposure in EEU
(chamber)• PE, 12 mg, IR, orally-administered• Primary endpoint: subjective change from baseline over
6 hour period• PE not significantly different from placebo; PSE
significantly more effective than placebo
NDAC December 14, 200740
SP P04822
• 2007• Primary objective: Loratidine-Montelukast (LMC) vs.
placebo• R, double blind, placebo control, parallel, single-dose • PE arm: n = 126 (vs. 126 placebo)• Congestion induced by exposure to ragweed in
EEU (chamber)• PE, 10 mg, IR, orally-administered• Primary endpoint: subjective change from baseline
every 20 min over 8 hour period• LMC significantly more effective than placebo; PE not
significantly different from placebo over the first 6 h
NDAC December 14, 200741
Why NAR?• Preferred if interested in physiological (vs.
symptomatic) change– Eccles: “Decongestant claim should be backed up with
objective demonstration of effectiveness; claims of symptom relief should be supported by changes in symptom scores.”
• Sensation of respiration determined partly by sensation of cooling of nasal epithelium in anterior 1/3 of nose– Menthol provides sensation of improved airflow
• Asymptomatic nasal obstruction• No obstruction but complain of congestion
NDAC December 14, 200742
Significant Effect - NAREliz2
10 mg dose
25 mg dose
NDAC December 14, 200743
Study Concerns
• Summary memoranda– No protocols– Lack details (e.g. of statistical tests)
• Heterogeneity in methodology (both objective and subjective measures)
• Small (pilot studies?)
• NAR technique not standardized– 1984, 2000 international standards
NDAC December 14, 200744
Adverse Event Reporting System* (1969 – 10/3/07)
• 16 unique cases in which the only drug exposure reported was to an oral, single ingredient phenylephrine product
• Serious outcome: 1 case – 44 yo female experienced hemorrhagic stroke. Amount of
PE ingested, duration of treatment and temporal relationship to AE not reported
• Hypersensitivity: 3 cases– URT swelling, pruritis and dyspnea following ingestion of 10
mg dose PE in three patients 45 – 47 yo • Miscellaneous Events: 2 cases
– 50 yo female experienced chest pain following single 10 mg dose
– 37 yo male experienced abnormal behavior, depressed level of consciousness, hyperhidrosis, paresthesia following 10 mg qd x 2 days
* Limitations of AERS: underreporting, variable quality of reports, causality of drug uncertain, and inaccurate numerator and no denominator