dextromethorphan/pseudoephedrine/guaifenesin (Capmist DM Tablets, ExeFen DMX Tablets)

Dosing and uses of Capmist DM Tablets, ExeFen DMX Tablets (dextromethorphan/pseudoephedrine/guaifenesin)

• Adult
• Pediatric

 

Adult dosage forms and strengths

dextromethorphan/pseudoephedrine/guaifenesin

liquid

• 10mg/20mg/200mg

tablet

• 20mg/30mg/400mg
• 20mg/20mg/400mg
• 20mg/60mg/400mg
• 20mg/40mg/400mg

 

Temporary Relief of Nasal Congestion & Cough Due to Bronchial Irritation

5 mL PO q4-6hr; not to exceed 30 mL/day

1 tab [(20mg/30mg/400mg)] PO q4-6hr; not to exceed 6 tabs/day

1 tab [(20mg/40mg/400mg)] PO q4-6hr; not to exceed 6 tabs/day

 

Pediatric dosage forms and strengths

dextromethorphan/pseudoephedrine/guaifenesin

liquid

• 10mg/20mg/200mg

tablet

• 20mg/30mg/400mg
• 20mg/20mg/400mg
• 20mg/60mg/400mg
• 20mg/40mg/400mg

 

Temporary Relief of Nasal Congestion & Cough Due to Bronchial Irritation

<6 Years

• Ask a pediatrician

6-12 Years

• 2.5 mL PO q4-6hr; not to exceed 15 mL/day
• ½ tablet [(20mg/40mg/400mg/tab)] PO q4-6hr; not to exceed 3 tablets/day

>12 Years

• 5 mL PO q4-6hr; not to exceed 30 mL/day
• 1 tab [(20mg/30mg/400mg)] PO q4-6hr; not to exceed 6 tabs/day
• 1 tab [(20mg/40mg/400mg)] PO q4-6hr; not to exceed 6 tabs/day

 

Capmist DM Tablets, ExeFen DMX Tablets (dextromethorphan/pseudoephedrine/guaifenesin) adverse (side) effects

Frequency not defined

Arrhythmia

Palpitations

Convulsion

Dizziness

Headache

Drowsiness

Excitability

Weakness

Tremor

Nausea

Vomiting

 

Warnings

Contraindications

Contraindicated in documented hypersensitivity to the drugs or within 14 days of MAO inhibitor therapy; known G-6-PD deficiency

 

Cautions

Caution in cardiovascular disease, diabetes mellitus, prostatic hypertrophy and increased intraocular pressure when taking pseudoephedrine

Acetaminophen hepatotoxicity possible in chronic alcoholics following various dose levels; severe or recurrent pain or high or continued fever may indicate a serious illness; contained in many OTC products and combined use with these products may result in toxicity due to cumulative doses exceeding recommended maximum dose

Do not take dextromethorphan for persistent or chronic cough associated with smoking, asthma, or emphysema, or if it is accompanied by excessive phlegm unless directed by a healthcare provider; dextromethorphan may slow the breathing

 

Pregnancy and lactation

Pregnancy category: C

Lactation: excretion in milk unknown/contraindicated

Pregnant or breastfeeding patients should seek advice of health professional before using OTC drugs

 

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 Capmist DM Tablets, ExeFen DMX Tablets (dextromethorphan/pseudoephedrine/guaifenesin)

Mechanism of action

Dextromethorphan is a cough suppressant that acts centrally on the cough center in the medulla.

Guaifenesin increases respiratory tract fluid secretions and helps to loosen phlegm and bronchial secretions.

Pseudoephedrine stimulates the alpha-adrenergic receptors causing bronchodilation and vasoconstriction.

 

Pharmacokinetics

Dextromethorphan

• Onset: 15-30 min
• Duration: 3-6 hr
• Metabolism: Hepatic P450 enzyme CYP2D6
• Excretion: Urine
• Half-life: 2-4 hr (extensive metabolizers); 24 hr (poor metabolizers)
• Peak plasma time: 2-3 hr

Guaifenesin

• Half-Life: 1 hr
• Onset: 30 min
• Duration: 4-6 hr
• Metabolism: Liver
• Metabolite: b-(2-methoxyphenoxy) lactic acid
• Excretion: Urine

Pseudoephedrine

• Half-Life: 3 hr (children); 9-16 hr (adults)
• Onset: 30 min (decongestant)
• Duration: 3-8 hr  Peak Plasma
• Time: 1.97 hr
• Concentration: 422 ng/mL
• Metabolism: Liver, by N-demethylation
• Metabolites: Inactive
• Clearance: 7.3-7.6 mL/min/kg
• Excretion: Urine (43-96%)