Karbinal
(carbinoxamine maleate)Karbinal Prescribing Information
Karbinal ER is indicated for adults and pediatric patients 2 years of age and older for the symptomatic treatment of:
- Seasonal and perennial allergic rhinitis
- Vasomotor rhinitis
- Allergic conjunctivitis due to inhalant allergens and foods
- Mild, uncomplicated allergic skin manifestations of urticaria and angioedema
- Dermatographism
- As therapy for anaphylactic reactions adjunctive to epinephrine and other standard measures after the acute manifestations have been controlled
- Amelioration of the severity of allergic reactions to blood or plasma
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
Extended-release oral suspension: 4 mg carbinoxamine maleate per 5 mL
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.
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)].
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.
Geriatric Use
Karbinal ER may cause dizziness, hypotension, confusion, or over-sedation in the elderly. Start elderly patients on lower doses and observe closely.
Karbinal ER is contraindicated in:
- children younger than 2 years of age because deaths have been reported in this age group (see Warnings and Precautions (5.1)]
- patients who are hypersensitive to carbinoxamine maleate or any of the inactive ingredients in Karbinal ER [see Warnings and Precautions (5.1)]
- patients who are taking monoamine oxidase inhibitors (MAOI) [see Drug Interactions(7)].
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.
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.
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.
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.
The following clinically significant adverse reactions are descrived elsewhere in the labeling:
- Somnolense and Impaired Mental Alertness [see Warnings and Precautions (5.2)].
- Allergic Reactions due to Sulfites, including Anaphylaxis [see Warnings and Precautions (5.2)].
The most frequent adverse reactions include: sedation, sleepiness, dizziness, disturbed coordination, epigastric distress, and thickening of bronchial secretions. In clinical use, younger children and older adults may be particularly sensitive to adverse reactions [see Pediatric Use (8.4) and Geriatric Use (8.5)].
The following adverse reactions, listed by body system, have been identified in case reports and during the use of carbinoxamine in observational studies. 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.
Body as a Whole: Urticaria, drug rash, anaphylactic shock, photosensitivity, excessive perspiration, chills, dryness of mouth, nose and throat.
Cardiovascular: Hypotension, headache, palpitations, tachycardia, extrasystoles.
Central Nervous System: Fatigue, confusion, restlessness, excitation, nervousness, tremor, irritability, insomnia, euphoria, paresthesia, blurred vision, diplopia, vertigo, tinnitus, acute labyrinthitis, hysteria, neuritis, convulsions.
Gastrointestinal: Anorexia, nausea, vomiting, diarrhea, constipation.
Hematologic: Hemolytic anemia, thrombocytopenia, agranulocytosis.
Laboratory: Increase in uric acid levels.
Respiratory: Tightness of chest and wheezing, nasal stuffiness.
Urogenital: Urinary frequency, difficult urination, urinary retention, early menses.
- Do not use of Karbinal ER in patients who are taking monoamine oxidase inhibitors (MAOIs), which prolong and intensify the anticholinergic (drying) effects of antihistamines.
- Avoid use of Karbinal ER with alcohol and other CNS depressants (hypnotics, sedatives, tranquilizers, etc.) due to additive effects.
Each 5 mL of Karbinal ER Extended-release Oral Suspension contains carbinoxamine complexed with polistirex equivalent to 4 mg carbinoxamine maleate and the following inactive ingredients: citric acid anhydrous, strawberry-banana flavor, glycerin, high fructose corn syrup, methylparaben, modified food starch, polysorbate 80, polyvinyl acetate, povidone, propylparaben, purified water, sodium metabisulfite, sodium polystyrene sulfonate, sucrose, triacetin, and xanthan gum.
Carbinoxamine maleate is freely soluble in water. The chemical name is 2-[(4-chlorophenyl)-2-pyridinylmethoxy]- N, N-dimethylethanamine (Z)-2-butenedioate (1:1), which has the following structure:
The drug-polistirex complex is formed with the active ingredient (carbinoxamine maleate, USP) and sodium polystyrene sulfonate, USP, which has the following structure:
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.
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.
. 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.
The effectiveness and safety of Karbinal ER is based on demonstration of bioequivalence to the immediate-release reference product [see Pharmacokinetics (12.3)].
Karbinal ER Oral Suspension contains 4 mg carbinoxamine maleate per 5 mL. It is a light beige to tan viscous suspension with strawberry-banana flavor and is supplied as follows:
NDC 23594-101-05 Bottles of 16 fl oz (480 mL)
NDC 23594-101-01 Bottles of 1 fl oz (30 mL) Physician Samples
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.
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.