Acetaminophen and guaifenesin

Name: Acetaminophen and guaifenesin

What is acetaminophen and guaifenesin?

Acetaminophen is a pain reliever and a fever reducer. It is used to treat many conditions, such as headache, muscle aches, arthritis, backache, toothaches, colds, and fevers.

Guaifenesin is an expectorant. It helps loosen congestion in your chest and throat, making it easier to cough out through your mouth.

Acetaminophen and guaifenesin is a combination medicine used to treat headache, aches and pains, fever, and chest congestion caused by common cold or flu. It also loosens phlegm (mucus) in your chest to help you breathe more easily.

Guaifenesin will not treat a cough that is caused by smoking, asthma, or emphysema.

Acetaminophen and guaifenesin may also be used for purposes not listed in this medication guide.

What happens if I miss a dose?

Since this medicine is used when needed, you may not be on a dosing schedule. If you are on a schedule, use the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not use extra medicine to make up the missed dose.

For Healthcare Professionals

Applies to acetaminophen / guaifenesin: oral liquid, oral powder for reconstitution, oral tablet

Hepatic

Hepatic side effects of acetaminophen have included severe and sometimes fatal dose dependent hepatitis in alcoholic patients. Hepatotoxicity has been increased during fasting. Several cases of hepatotoxicity from chronic acetaminophen therapy at therapeutic doses have also been reported despite a lack of risk factors for toxicity.[Ref]

Alcoholic patients may develop hepatotoxicity after even modest doses of acetaminophen. In healthy patients, approximately 15 grams of acetaminophen is necessary to deplete liver glutathione stores by 70% in a 70 kg person. However, hepatotoxicity has been reported following smaller doses. Glutathione concentrations may be repleted by the antidote N-acetylcysteine. One case report has suggested that hypothermia may also be beneficial in decreasing liver damage during overdose.

In a recent retrospective study of 306 patients admitted for acetaminophen overdose, 6.9% had severe liver injury but all recovered. None of the 306 patients died.

A 19 year old female developed hepatotoxicity, reactive plasmacytosis and agranulocytosis followed by a leukemoid reaction after acute acetaminophen toxicity.[Ref]

Dermatologic

Dermatologic side effects of acetaminophen have included rare reports of erythematous skin rashes. Acetaminophen associated bullous erythema and purpura fulminans have also been reported. Acetaminophen has been associated with a risk of rare but potentially fatal serious skin reactions known as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and acute generalized exanthematous pustulosis (AGEP).

Dermatologic side effects of guaifenesin have included rare reports of rash.[Ref]

Gastrointestinal

Gastrointestinal side effects of acetaminophen have included rare cases of acute pancreatitis.

Gastrointestinal side effects of guaifenesin have included stomach upset and vomiting with higher than recommended doses. Doses recommended for expectoration have rarely been associated with gastrointestinal upset.[Ref]

One study has suggested that acetaminophen may precipitate acute biliary pain and cholestasis. The mechanism of this effect may be related to inhibition of prostaglandin and alterations in the regulation of the sphincter of Oddi.[Ref]

Nervous system

Nervous system side effects of guaifenesin have occasionally included dizziness and headache.[Ref]

Hematologic

Hematologic side effects of acetaminophen have included rare cases of thrombocytopenia. Methemoglobinemia with resulting cyanosis has also been observed in the setting of acute overdose.[Ref]

Renal

Acute tubular necrosis usually occurs in conjunction with liver failure, but has been observed as an isolated finding in rare cases. A possible increase in the risk of renal cell carcinoma has been associated with chronic acetaminophen use as well.

A recent case control study of patients with end-stage renal disease suggested that long term consumption of acetaminophen may significantly increase the risk of end-stage renal disease particularly in patients taking more than two pills per day.[Ref]

Renal side effects of acetaminophen have included rare cases of acute tubular necrosis and interstitial nephritis. Adverse renal effects are most often observed after overdose, after chronic abuse (often with multiple analgesics), or in association with acetaminophen-related hepatotoxicity.[Ref]

Hypersensitivity

Hypersensitivity side effects of acetaminophen have included rare reports of anaphylaxis and fixed drug eruptions.[Ref]

Cardiovascular

Two cases hypotension have been reported following the administration of acetaminophen. Both patients experienced significant decreases in blood pressure. One of the two patients required pressor agents to maintain adequate mean arterial pressures. Neither episode was associated with symptoms of anaphylaxis. Neither patient was rechallenged after resolution of the initial episode.[Ref]

Cardiovascular side effects of acetaminophen have included two cases of hypotension.[Ref]

Respiratory

Respiratory side effects of acetaminophen have included a case of eosinophilic pneumonia.[Ref]

Some side effects of acetaminophen / guaifenesin may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Usual Adult Dose for Headache

Acetaminophen-guaifenesin 325 mg-200 mg oral tablet:
2 tablets orally every 4 to 6 hours not to exceed 12 tablets daily.

Acetaminophen-guaifenesin 500 mg-200 mg/15 mL oral liquid:
30 mL orally every 4 to 6 hours not to exceed 120 mL per day.

Acetaminophen-guaifenesin 1000 mg-400 mg oral powder for reconstitution:
1 packet orally every 6 hours not to exceed 4 packets in 24 hours.

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