chlorpheniramine/dextromethorphan (Children's Robitussin Cough and Cold Long-Acting, St. Joseph Cough and Cold)

Dosing and uses of Robitussin Cough and Cold Long-Acting (chlorpheniramine-dextromethorphan)

• Adult
• Pediatric

 

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)