Dosing & Uses
Dosage Forms & Strengths
acetaminophen/guaifenesin
packet
- 1000mg/400mg
Cough, Fever, Headache, Minor Aches & Pains
1 packet dissolved in 8 oz of hot water q6hr; not to exceed 4 packets/day; consume entire drink within 10-15 minutes
Dosage Forms & Strengths
acetaminophen/guaifenesin
tablet
- 325mg/200mg
capsule
- 325mg/200mg
oral solution
- (500mg/200mg)/15mL
packet
- 1000mg/400mg
Cough, Fever, Headache, Minor Aches & Pains
<12 years
- Ask a pediatrician
>12 years
- 1 packet dissolved in 8 oz of hot water q6hr; not to exceed 4 packets/day; consume entire drink within 10-15 minutes
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Adverse Effects
Frequency Not Defined
Dizziness
Drowsiness
Headache
Dermatologic rash
Nausea
Vomiting
Anemia blood dyscrasias (neutropenia, pancytopenia, leukopenia)
Bilirubin and alkaline phosphatase may increase
Warnings
Contraindications
Hypersensitivity
G-6-PD deficiency
Severe hepatic impairment
Cautions
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
Acetaminophen: Risk for rare, but serious skin reactions that can be fatal; these reactions include Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP); symptoms may include skin redness, blisters and rash
Guaifenesin is not for administration in persistent cough associated with chronic bronchitis, smoking, asthma, or accompanied with excessive secretions
Pregnancy & 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
Mechanism of Action
Acetaminophen blocks pain impulse generation peripherally & may inhibit the generation of prostaglandin in the CNS; reduces fever by inhibiting the hypothalamic heat-regulating center
Guaifenesin increases respiratory tract fluid secretions & helps to loosen phlegm & bronchial secretions
Pharmacokinetics
Acetaminophen
- Peak plasma time: 10-60 min (PO immediate release); 60-120 min (PO extended release); 6 hr (PO 500 mg tablet); 8 hr (PO 650 mg extended release tablet)
- Vd: 1 L/kg
- Protein binding: 10-25%
- Metabolism: Liver (microsomal enzyme systems); conjugation (glucuronic acid)
- Half-life: 1.25-3hr
- Excretion: Urine
Guaifenesin
- Half-Life: 1 hr
- Onset: 30 min
- Duration: 4-6 hr
- Metabolism: Liver
- Metabolite: b-(2-methoxyphenoxy) lactic acid
- Excretion: Urine