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Pronunciation
(klor fen IR a meen)
Generic Available (U.S.)
Yes: Syrup, tablet
Index Terms
Brand Names: U.S.
Brand Names: Canada
Pharmacologic Category
Pharmacologic Category Synonyms
Use: Labeled Indications
Perennial and seasonal allergic rhinitis and other allergic symptoms including urticaria
Use: Dental
Treatment of histamine-induced allergic symptoms
Pregnancy Risk Factor
C
Pregnancy Considerations
Reproduction studies have not been conducted with chlorpheniramine tannate.
Lactation
Enters breast milk
Contraindications
Hypersensitivity to chlorpheniramine maleate or any component of the formulation; narrow-angle glaucoma; bladder neck obstruction; symptomatic prostate hypertrophy; during acute asthmatic attacks; stenosing peptic ulcer; pyloroduodenal obstruction. Avoid use in premature and term newborns due to possible association with SIDS.
Warnings/Precautions
Concerns related to adverse effects:
• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks which require mental alertness (eg, operating machinery or driving).
Disease-related concerns:
• Cardiovascular disease: Use with caution in patients with cardiovascular disease (including hypertension and ischemic heart disease).
• Increased intraocular pressure: Use with caution in patients with increased intraocular pressure.
• Prostatic hyperplasia/urinary obstruction: Use with caution in patients with prostatic hyperplasia and/or GU obstruction.
• Respiratory disease: Use with caution in patients with asthma or other chronic breathing disorders.
• Thyroid dysfunction: Use with caution in patients with thyroid dysfunction.
Concurrent drug therapy issues:
• Sedatives: Effects may be potentiated when used with other sedative drugs or ethanol.
Special populations:
• Elderly: Avoid use of this potent anticholinergic agent due to increased risk of confusion, dry mouth, constipation, and other anticholinergic effects; clearance decreases in patients of advanced age (Beers Criteria).
• Pediatrics: Antihistamines may cause excitation in young children. Not for OTC use in children <2 years of age.
Adverse Reactions
>10%:
Central nervous system: Slight to moderate drowsiness
Respiratory: Thickening of bronchial secretions
1% to 10%:
Central nervous system: Headache, excitability, fatigue, nervousness, dizziness
Gastrointestinal: Nausea, xerostomia, diarrhea, abdominal pain, appetite increase, weight gain
Genitourinary: Urinary retention
Neuromuscular & skeletal: Arthralgia, weakness
Ocular: Diplopia
Renal: Polyuria
Respiratory: Pharyngitis
Metabolism/Transport Effects
Substrate of CYP2D6 (minor), CYP3A4 (major); Note: Assignment of Major/Minor substrate status based on clinically relevant drug interaction potential; Inhibits CYP2D6 (weak)
Drug Interactions
Acetylcholinesterase Inhibitors (Central): Anticholinergics may diminish the therapeutic effect of Acetylcholinesterase Inhibitors (Central). Acetylcholinesterase Inhibitors (Central) may diminish the therapeutic effect of Anticholinergics. If the anticholinergic action is a side effect of the agent, the result may be beneficial. Risk C: Monitor therapy
Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Risk C: Monitor therapy
Amphetamines: May diminish the sedative effect of Antihistamines. Risk C: Monitor therapy
Anticholinergics: May enhance the adverse/toxic effect of other Anticholinergics. Exceptions: Levocabastine (Nasal); Paliperidone. Risk C: Monitor therapy
ARIPiprazole: CYP2D6 Inhibitors (Weak) may increase the serum concentration of ARIPiprazole. Management: Monitor for increased aripiprazole pharmacologic effects. Aripiprazole dose adjustments may or may not be required based on concomitant therapy and/or indication. Consult product labeling for specific recommendations. Risk C: Monitor therapy
Benzylpenicilloyl Polylysine: Antihistamines may diminish the diagnostic effect of Benzylpenicilloyl Polylysine. Management: Suspend systemic H1 antagonists for benzylpenicilloyl-polylysine skin testing and delay testing until systemic antihistaminic effects have dissipated. A histamine skin test may be used to assess persistent antihistaminic effects. Risk D: Consider therapy modification
Betahistine: Antihistamines may diminish the therapeutic effect of Betahistine. Risk C: Monitor therapy
CNS Depressants: May enhance the adverse/toxic effect of other CNS Depressants. Exceptions: Levocabastine (Nasal). Risk C: Monitor therapy
Conivaptan: May increase the serum concentration of CYP3A4 Substrates. Risk X: Avoid combination
CYP3A4 Inhibitors (Moderate): May decrease the metabolism of CYP3A4 Substrates. Risk C: Monitor therapy
CYP3A4 Inhibitors (Strong): May decrease the metabolism of CYP3A4 Substrates. Risk D: Consider therapy modification
Dasatinib: May increase the serum concentration of CYP3A4 Substrates. Risk C: Monitor therapy
Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (e.g., opioids, barbiturates) with concomitant use. Risk D: Consider therapy modification
Hyaluronidase: Antihistamines may diminish the therapeutic effect of Hyaluronidase. Management: Patients receiving antihistamines (particularly at larger doses) may not experience the desired clinical response to standard doses of hyaluronidase. Larger doses of hyaluronidase may be required. Risk D: Consider therapy modification
HydrOXYzine: May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
Ivacaftor: May increase the serum concentration of CYP3A4 Substrates. Risk C: Monitor therapy
Methotrimeprazine: CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. Risk D: Consider therapy modification
Metyrosine: CNS Depressants may enhance the sedative effect of Metyrosine. Risk C: Monitor therapy
Mifepristone: May increase the serum concentration of CYP3A4 Substrates. Management: Minimize doses of CYP3A4 substrates, and monitor for increased concentrations/toxicity, during and 2 weeks following treatment with mifepristone. Avoid cyclosporine, dihydroergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, and tacrolimus. Risk D: Consider therapy modification
Peginterferon Alfa-2b: May decrease the serum concentration of CYP2D6 Substrates. Risk C: Monitor therapy
Pramlintide: May enhance the anticholinergic effect of Anticholinergics. These effects are specific to the GI tract. Risk D: Consider therapy modification
Selective Serotonin Reuptake Inhibitors: CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced. Risk C: Monitor therapy
Tocilizumab: May decrease the serum concentration of CYP3A4 Substrates. Risk C: Monitor therapy
Ethanol/Nutrition/Herb Interactions
Ethanol: May increase CNS depression; monitor for increased effects with coadministration. Caution patients about effects.
Storage
Protect from light.
Mechanism of Action
Competes with histamine for H1-receptor sites on effector cells in the gastrointestinal tract, blood vessels, and respiratory tract
Pharmacodynamics/Kinetics
Distribution: Vd: Children: 4-7 L/kg; Adults: 6-12 L/kg (Paton, 1985)
Protein binding: 33% (range: 29% to 37%) (Martínez-Gómez, 2007)
Metabolism: Hepatic via CYP450 enzymes (including CYP2D6 and other unidentified enzymes) to active and inactive metabolites; significant first-pass effect (Sharma, 2003)
Half-life elimination: Serum: Children: 10-13 hours; Adults: 14-24 hours (Paton, 1985)
Time to peak: 2-3 hours (Sharma, 2003)
Excretion: Urine (Sharma, 2003)
Dosage
Oral:
Children: 0.35 mg/kg/day in divided doses every 4-6 hours
2-6 years: 1 mg every 4-6 hours, not to exceed 6 mg in 24 hours
6-12 years: 2 mg every 4-6 hours, not to exceed 12 mg/day or sustained release 8 mg at bedtime
Children >12 years and Adults: 4 mg every 4-6 hours, not to exceed 24 mg/day or sustained release 8-12 mg every 8-12 hours, not to exceed 24 mg/day
Elderly: 4 mg once or twice daily. Note: Duration of action may be 36 hours or more when serum concentrations are low.
Hemodialysis: Supplemental dose is not necessary
Administration: Oral
May be administered with food or water. Timed release oral forms are to be swallowed whole, not crushed or chewed.
Test Interactions
May suppress the wheal and flare reactions to skin test antigens.
Dietary Considerations
May be taken with food or water. Some products may contain phenylalanine.
Geriatric Considerations
Anticholinergic action may cause significant confusional symptoms, constipation, or problems voiding urine. If an antihistamine is indicated, a second generation nonsedating antihistamine would be a more appropriate choice.
This medication is considered to be potentially inappropriate in this patient population (Beers Criteria: Quality of evidence - moderate; Strength of recommendation - strong).
Additional Information
Not effective for nasal stuffiness.
Dental Health: Effects on Dental Treatment
Key adverse event(s) related to dental treatment: Xerostomia (normal salivary flow resumes upon discontinuation). Chronic use of antihistamines will inhibit salivary flow, particularly in elderly patients; this may contribute to periodontal disease and oral discomfort.
Dental Health: Vasoconstrictor/Local Anesthetic Precautions
No information available to require special precautions
Mental Health: Effects on Mental Status
Drowsiness is common; may cause excitability, nervousness, fatigue, or depression
Mental Health: Effects on Psychiatric Treatment
Dry mouth and sedation may be exacerbated by concurrent psychotropic use
Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Suspension, oral, as tannate [drops]:
Ed Chlorped: 2 mg/mL (60 mL [DSC])
Syrup, oral, as maleate:
Aller-Chlor®: 2 mg/5 mL (118 mL) [contains ethanol 5%, propylene glycol]
Diabetic Tussin® for Children Allergy Relief: 2 mg/5 mL (118 mL) [dye free, ethanol free, sugar free; contains phenylalanine 8.4 mg/5 mL]
Tablet, oral, as maleate: 4 mg
Aller-Chlor®: 4 mg [scored]
Allergy Relief: 4 mg
Chlor Hist: 4 mg
Chlor-Trimeton® Allergy: 4 mg
Chlorphen: 4 mg
Ed-Chlortan: 4 mg [scored]
Teldrin® HBP: 4 mg
Tablet, extended release, oral, as maleate:
Chlor-Trimeton® Allergy: 12 mg
Tablet, long acting, oral, as tannate:
Ahist™: 12 mg [scored]
References
"American Geriatrics Society Updated Beers Criteria for Potentially Inappropriate Medication Use in Older Adults," J Am Geriatr Soc, 2012 [epub ahead of print].
Martínez-Gómez MA, Villanueva-Camañas RM, Sagrado S, et al, "Evaluation of Enantioselective Binding of Antihistamines to Human Serum Albumin by ACE," Electrophoresis, 2007, 28(15):2635-43.
Paton DM and Webster DR, "Clinical Pharmacokinetics of H1-Receptor Antagonists (The Antihistamines)," Clin Pharmacokinet, 1985, 10(6):477-97.
Sharma A and Hamelin BA, "Classic Histamine H1 Receptor Antagonists: A Critical Review of Their Metabolic and Pharmacokinetic Fate from a Bird's Eye View," Curr Drug Metab, 2003, 4(2):105-29.
International Brand Names
Lexi-Comp.com
Last full review/revision April 2012
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