brompheniramine/dextromethorphan/phenylephrine (Neo DM Suspension, Dimaphen DM, Children's Dimetapp Cold and Cough)
Classes: Cough/Cold, Non-narcotic Combos; Antihistamine/Antitussive/Decongestant Combos
- Dosing and uses of Neo DM Suspension, Dimaphen DM (brompheniramine/dextromethorphan/phenylephrine)
- Neo DM Suspension, Dimaphen DM (brompheniramine/dextromethorphan/phenylephrine) adverse (side) effects
- Warnings
- Pregnancy
- Pharmacology of Neo DM Suspension, Dimaphen DM (brompheniramine/dextromethorphan/phenylephrine)
Dosing and uses of Neo DM Suspension, Dimaphen DM (brompheniramine/dextromethorphan/phenylephrine)
Adult dosage forms and strengths
brompheniramine/dextromethorphan/phenylephrine
oral solution
- (1mg/5mg/2.5mg)/5mL
Relief of Cold Symptoms
4 teaspoons (20 mL) PO q4hr; not to exceed 120 mL/24 hr
Pediatric dosage forms and strengths
brompheniramine/dextromethorphan/phenylephrine
oral solution
- (1mg/5mg/2.5mg)/5mL
Relief of Cold Symptoms
<6 years
- Not recommended
6-12 years
- 2 teaspoons (10 mL) PO q4hr
>12 years
- 4 teaspoons (20 mL) PO q4hr
Neo DM Suspension, Dimaphen DM (brompheniramine/dextromethorphan/phenylephrine) adverse (side) effects
Frequency not defined
Dizziness
Drowsiness
Dry mouth, throat, and nose
Thickening of mucus in nose or throat GI disturbances
Reflex tachycardia
Excitability
Restlessness
Headache
Hypertension
Severe peripheral and visceral vasoconstriction
Warnings
Contraindications
Hypersensitivity
Asthma
< 2 years of age
Severe hypertension
Narrow-angle glaucoma
Symptomatic prostate hypertrophy
Bladder-neck obstruction
Stenosing peptic ulcer
Use within 14 days of MAO inhibitor therapy
Cautions
Brompheniramine: May cause significant confusional symptoms; not for administration to premature or full-term neonates
Dextromethorphan: Do not take 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; may decrease respiration rate
Phenylephrine: Caution in elderly patients, hyperthyroidism, myocardial disease, bradycardia, partial heart block or severe arteriosclerosis
Pregnancy and lactation
Pregnancy category: C
Lactation: excreted in breast milk; use caution
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 Neo DM Suspension, Dimaphen DM (brompheniramine/dextromethorphan/phenylephrine)
Mechanism of action
Brompheniramine: Competitively blocks histamine from binding to H1 receptors; significant antimuscarinic activity and penetrates CNS, which causes pronounced tendency to induce sedation
Dextromethorphan: Cough suppressant that acts centrally on the cough center in medulla
Phenylephrine: Vasoconstrictor & decongestant that relieves symptoms resulting from irritation of upper respiratory tract tissue; shrinks swollen mucous membranes, reduces nasal congestion and tissue hyperemia
Pharmacokinetics
Brompheniramine
- Onset: 15-30 min
- Duration: 3-9 hr, may last 48 hr
- Peak Plasma Time: 2-5 hr
- Vd: 11.7 L/kg (adults); 20 L/kg (children)
- Protein binding: 39-49%
- Metabolism: Mainly liver; metabolites include propionic acid derivative conjugated with glycine
- Half-Life: 11.8 (children); 25 hr (adults)
- Excretion: Urine
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
Phenylephrine
- Half-life: 2-3 hr
- Onset: 10-15 min
- Duration: 15 min
- Bioavailability: < 38%
- Excretion: Urine (80-90%)
- Peak plasma time: 0.75-2 hr
- Vd: 26-61 L
- Vdss: 340 L