Drug information of Carbinoxamine

Mechanism of effect

Carbinoxamine competes with free histamine for binding at HA-receptor sites. This antagonizes the effects of histamine on HA-receptors, leading to a reduction of the negative symptoms brought on by histamine HA-receptor binding. Carbinoxamine's anticholinergic action appears to be due to a central antimuscarinic effect, which also may be responsible for its antiemetic effects, although the exact mechanism is unknown.

Pharmacodynamic

Carbinoxamine is a first generation antihistamine of the ethanolamine class. Ethanolamine antihistamines have significant antimuscarinic activity and produce marked sedation in most patients. In addition to the usual allergic symptoms, the drug also treats irritant cough and nausea, vomiting, and vertigo associated with motion sickness. It also is used commonly to treat drug-induced extrapyramidal symptoms as well as to treat mild cases of Parkinson's disease. Carbinoxamine competitively antagonizes the effects of histamine on HA-receptors in the GI tract, uterus, large blood vessels, and bronchial muscle. Ethanolamine derivatives have greater anticholinergic activity than do other antihistamines, which probably accounts for the antidyskinetic action of carbinoxamine.

Pharmacokinetics

Half-Life: 10-20 hr

Metabolism: Hepatic

Excretion: Urine

Drug indications

Allergy

Dosage

Adult        

Allergies

4-8 mg PO q6-8hr PO; not to exceed 24 mg/day

Karbinal ER: 6-16 mg (7.5-20 mL) PO q12hr

Pediatric

Allergies

2-6 years: 0.2-0.4 mg/kg/day PO divided q6-8hr or 1-2 mg (2.5 mL) PO q6-8hr  

>6 years: 2-4 mg (5-7.5 mL) PO q6-8hr

Karbinal ER

• 2-3 years: 3-4 mg (3.75-5 mL) PO q12hr
• 4-5 years: 3-8 mg (3.75-10 mL) PO q12hr
• 6-11 years: 6-12 mg (7.5-15 mL) PO q12hr
• ≥12 years: 6-16 mg (7.5-20 mL) PO q12hr

Drug contraindications

Asthma , Breast feeding , Hypersensitivity

Side effects

Anxiety , Insomnia , Diarrhea , Headache , nausea , vomiting , Seizures , Blurred vision , vertigo , Hypertension , hypotension , palpitations , impotence , anorexia , Tremor , urinary retention , sweating , lethargy , Agranulocytosis , Diplopia , difficulty urinating , Restlessness , Leukopenia , thrombocytopenia , stuffy nose

Interactions

Acetylcholine , potassium citrate , Tranylcypromine , Topiramate , Zonisamide , Sodium Oxybate , isocarboxazid , propoxyphene , Eluxadoline , glycopyrrolate topical , Ethchlorvynol

Alerts

Narrow-angle glaucoma, prostatic hypertrophy, peptic ulcer, GI obstruction, bladder outflow obstruction, history of bronchial asthma, incr IOP, HTN, hyperthyroidism, cardiovascular dz

May affect mental alertness

Elderly

Points of recommendation

Use exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

You may need to shake the oral suspension (liquid) before using. Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup.

Call your doctor if your symptoms do not improve after 7 days of treatment, or if you have a fever with a headache, cough, or skin rash.

Store at room temperature away from moisture, heat, and light.

Since carbinoxamine is used when needed, you may not be on a dosing schedule. If you are on a schedule, use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

Pregnancy level

Group c - Not adequate studies in pregnant women

Related drugs

Promethazine , Diphenhydramin , Dimenhydrinate , Cyproheptadine , Clemastine , Dexchlorpheniramine , Triprolidine , pyrilamine (Mepyramine) , Phenindamine , Tripelennamine , Terfenadine