chlorpheniramine/dextromethorphan (Children's Robitussin Cough and Cold Long-Acting, St. Joseph Cough and Cold)
Classes: Cough/Cold, Non-narcotic Combos; Antihistamine/Antitussive Combos
Dosing and uses of Robitussin Cough and Cold Long-Acting (chlorpheniramine-dextromethorphan)
Adult dosage forms and strengths
chlorpheniramine/dextromethorphan
softchew tablet
- 1mg/5mg
oral syrup
- (1mg/7.5mg)/5mL
- (2mg/15mg)/5mL
tablet
- 4mg/30mg
Cough & Cold
4mg chlorpheniramine/30mg dextromethorphan PO q6hr PRn
Pediatric dosage forms and strengths
chlorpheniramine/dextromethorphan
softchew tablet
- 1mg/5mg
oral syrup
- (1mg/7.5mg)/5mL
- (2mg/15mg)/5mL
tablet
- 4mg/30mg
Cough & Cold
<6 years
- Safety and efficacy not established
6-12 years
- Syrup: 2 mg chlorpheniramine/15 mg dextromethorphan PO q6hr
- Softchew tablet: 2 mg chlorpheniramine/10 mg dextromethorphan PO q4-6hr
>12 years
- 4mg chlorpheniramine/30mg dextromethorphan PO q6hr PRN
Robitussin Cough and Cold Long-Acting (chlorpheniramine-dextromethorphan) adverse (side) effects
Frequency not defined
Sedation ranging from mild drowsiness to deep sleep
CNS depression
Excitability may occur in children
Dizziness
Impaired coordination
Muscular weakness
Anorexia
Nausea
Vomiting
Urinary retention
Blurred vision
Xerostomia
Restlessness, insomnia, tremors, euphoria, nervousness, delirium, palpitations, seizures reported infrequently
Warnings
Contraindications
Hypersensitivity
Within 2 wk of taking a monoamine oxidase (MAO) inhibitor
Sedation of children
Cautions
Caution in children younger than 6 years
Benign prostatic hypertrophy
Glaucoma
Caution in productive cough (do not suppress expectoration of phlegm)
Chronic respiratory conditions (eg, asthma, COPD)
Alcohol consumption or other CNS depressants may increase risk for drowsiness
May impair ability to safely drive vehicle or operate machinery
Pregnancy and lactation
Pregnancy category: C
Lactation: Unknown whether distributed in breast milk, caution advised
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Robitussin Cough and Cold Long-Acting (chlorpheniramine-dextromethorphan)
Mechanism of action
Chlorpheniramine: Histamine H1-receptor antagonist; sedative effect is low; antihistamine and anticholinergic activity is moderate
Dextromethorphan: Antitussive; derivative of levorphanol; acts on cough center in medulla
Absorption
Peak Plasma Time: 2-6 hr (chlorpheniramine); 2-3 hr (dextromethorphan)
Onset: 15-30 min (dextromethorphan)
Duration: 3-6 hr (dextromethorphan)
Distribution
Protein Bound: 69-72% (chlorpheniramine)
Vd: 2.5-3.2 L/kg (chlorpheniramine)
Metabolism
Metabolism: GI mucosa, liver (chlorpheniramine); hepatic P450 enzyme CYP2D6 (dextromethorphan)
Metabolites: Monodesmethylchlorpheniramine, didesmethylchlorpheniramine
Elimination
Half-Life: 12-43 hr (chlorpheniramine); 2-4 hr (extensive dextromethorphan metabolizers); 24 hr (poor dextromethorphan metabolizers)
Excretion: Predominantly urine (chlorpheniramine and dextromethorphan)