2.1 Overview

The dosage of Karbinal ER should be individualized based on the severity of the condition and the response of the patient. Start with lower doses and increase as needed and tolerated.

2.2 Administration

Administer Karbinal ER by the oral route only. Measure Karbinal ER with an accurate milliliter measuring device. A household teaspoon is not an accurate measuring device and could lead to overdosage. A pharmacist can provide an appropriate measuring device and can provide instructions for measuring correct dose.

2.3 Recommended Dosage for Adults and Adolescents 12 years of age and older:

7.5 mL to 20 mL (6 to 16 mg) every 12 hours administered orally

2.4 Recommended Dosage for Pediatric Patients 2 to 11 years of age (approximately 0.2 to 0.4 mg/kg/day):

2 to 3 years: 3.75 mL to 5 mL (3 to 4 mg) every 12 hours administered orally

4 to 5 years: 3.75 mL to 10 mL (3 to 8 mg) every 12 hours administered orally

6 to 11 years: 7.5 mL to 15 mL (6 to 12 mg) every 12 hours administered orally

5.1 Pediatric Mortality

Deaths have been reported in children less than 2 years of age who were taking carbinoxamine-containing drug products; therefore, Karbinal ER is contraindicated in children younger than 2 years of age.

5.2 Somnolence and Impaired Mental Alertness

Karbinal ER may produce marked drowsiness and impair the mental or physical abilities required for the performance of potentially hazardous tasks such as driving a car or operating machinery. Advise patients to avoid engaging in hazardous tasks requiring mental alertness and motor coordination after ingestion of Karbinal ER. Avoid concurrent use of Karbinal ER with alcohol or other central nervous system depressants because additional impairment of central nervous system performance may occur.

5.3 Concomitant Medical Conditions

Karbinal ER has anticholinergic (atropine-like) properties and, therefore, should be used with caution in patients with: increased intraocular pressure, narrow angle glaucoma, hyperthyroidism, cardiovascular disease, hypertension, stenosing peptic ulcer, symptomatic prostatic hypertrophy, bladder neck obstruction, or pyloroduodenal obstruction.

5.4 Allergic Reactions due to Sulfites, including Anaphylaxis

Karbinal ER contains sodium metabisulfite, a sulfite that may cause allergic-type reactions, including anaphylaxis and life-threatening or less severe asthmatic episodes, in susceptible individuals. The overall prevalence of sulfite sensitivity in the general population is unknown and probably low. Sulfite sensitivity is seen more frequently in asthmatic than in nonasthmatic individuals.

8.1 Pregnancy

Risk Summary

Published data over decades of use of antihistamines, including carbinoxamine, have not identified a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal out comes. However, published dat a specifically evaluating the risk of carbinoxamine were not found. Animal reproductive studies have not been conducted with carbinoxamine maleate.

The estimated background risk of major birth defects and miscarriage for the indicated population 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 risks of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

8.2 Lactation

Risk Summary

Based on the physical properties of carbinoxamine, it is likely that carbinoxamine is present in breastmilk. There are published reports of drowsiness and irritability in infants exposed to antihistamines via breastmilk. There are post-marketing reports of deaths in children under 2 years of age exposed to carbinoxamine by oral administration. There are no available data on the effects on milk production. It is not recommended to breastfeed during treatment wit h Karbinal ER [see Warnings and Precautions (5.1)] and use in Specific Populations (8.4)].

8.4 Pediatric Use

Karbinal ER is contraindicated in pediatric patients younger than 2 years of age becuase deaths have been reported in this patient population who were taking carbinoxamine-containing drug products.

The safety and effectiveness of Karbinal ER in pediatric patients aged 2 years and older hve been established and I based on demonstration of bioequivalence to the immediate-release reference product [see Clinical Phamacology (12.3)]. Carbinoxamine may diminish mental alertness or produce sedation in children. Paradoxical reactions with excitation are more likely in younger children.

8.5 Geriatric Use

Karbinal ER may cause dizziness, hypotension, confusion, or over-sedation in the elderly. Start elderly patients on lower doses and observe closely.

12.1 Mechanism of Action

Carbinoxamine is an H 1 receptor antagonist (antihistamine) that exhibits anticholinergic (drying) and sedative properties.

Antihistamines compete with histamine for receptor sites on effector cells.

12.3 Pharmacokinetics

Karbinal ER after single-dose administration of 16 mg was bioequivalent to the reference carbinoxamine immediate-release oral solution after the administration of two doses of 8 mg six hours apart under fasting conditions. The carbinoxamine mean (SD) peak plasma concentration (C max) was 28.7 (5.3) ng/mL at 6.7 hours after Karbinal ER administration. The plasma half-life of carbinoxamine was 17.0 hours. There was no effect of food on the pharmacokinetic parameters.

Karbinal ER after multiple-dose administration of 16 mg every 12 hours for 8 days was bioequivalent to the reference carbinoxamine immediate-release oral solution after multiple-dose administration of 8 mg every 6 hours. The mean (SD) steady-state C max was 72.9 (24.4) ng/mL at 5.6 hours after Karbinal ER administration. Carbinoxamine mean (SD) minimum plasma concentration at steady-state was 51.8 (20.3) ng/mL.

13.1. Carcinogenesis, Mutagenesis, Impairment of Fertility

No long-term studies in animals have been performed to determine the possible effects of carbinoxamine on carcinogenesis, mutagenesis, and fertility.

Store at 25°C (77°F); excursions permitted from 15° to 30°C (59° to 86°F). [See USP Controlled Room Temperature.]

Dispense in tight, light-resistant container with child-resistant closure.

Administration

Advise patients to measure Karbinal ER with an accurate milliliter measuring device. A household teaspoon is not an accurate measuring device and could lead to overdosage. [see Dosage and Administration (2.2)].

Activities Requiring Mental Alertness

Advise patients to use caution when driving a motor vehicle or operating machinery. Karbinal ER may produce marked drowsiness and impair the mental or physical abilities required for the performance of potentially hazardous tasks such as driving a car or operating machinery [see Warnings and Precautions (5.2)].

MAOIs

Advise patients to not use MAOIs while taking Karbinal ER. MAOIs may prolong and intensify the anticholinergic (drying) effects [see Contraindications (4.4) and Drug Interactions (7)].

Lactation

Advise women that breastfeeding is not recommended during treatment with Karbinal ER [see Warnings and Precautions (5.1) and Use in Specific Populations (8.2 and 8.4)].

Manufactured by:

Tris Pharma, Inc.

Monmouth Junction, NJ 08852

Distributed by:

Aytu Therapeutics

Englewood, CO 80112

www.aytubio.com

LB8594

Rev 01

06/2021