Congestant Side Effects
Generic Name: acetaminophen / chlorpheniramine
Note: This page contains information about the side effects of acetaminophen / chlorpheniramine. Some of the dosage forms included on this document may not apply to the brand name Congestant.
For the Consumer
Applies to acetaminophen / chlorpheniramine: tablets
Check with your doctor if any of these most COMMON side effects persist or become bothersome:
Seek medical attention right away if any of these SEVERE side effects occur while taking acetaminophen / chlorpheniramine:
Constipation; diarrhea; dizziness; drowsiness; dry mouth, nose, or throat; excitability; headache; loss of appetite; nausea; nervousness or anxiety; trouble sleeping; upset stomach; vomiting; weakness.
Severe allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); dark urine or pale stools; difficulty urinating or inability to urinate; fast or irregular heartbeat; hallucinations; seizures; severe dizziness, lightheadedness, or headache; stomach pain; tremor; trouble sleeping; unusual fatigue; vision changes; yellowing of the skin or eyes.
For Healthcare Professionals
Applies to acetaminophen / chlorpheniramine: oral tablet
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]
Gastrointestinal side effects of acetaminophen have been rare, except in alcoholics and after overdose. Cases of acute pancreatitis have been reported rarely with the use of acetaminophen.
Gastrointestinal side effects of chlorpheniramine have included dry mouth and constipation in up to one-third of treated patients.[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]
Renal side effects of acetaminophen have included 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]
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]
Hypersensitivity side effects of acetaminophen have included anaphylaxis and fixed drug eruptions.[Ref]
A fatal case of agranulocytosis has been reported in a patient taking chlorpheniramine, pseudoephedrine, acetaminophen, dextromethorphan, phenylpropanolamine, and aspirin. Chlorpheniramine was felt to be the cause.[Ref]
Hematologic side effects of acetaminophen have included rare cases of thrombocytopenia. Acute thrombocytopenia has also been reported as having been caused by sensitivity to acetaminophen glucuronide, the major metabolite of acetaminophen. Methemoglobinemia with resulting cyanosis has also been observed in the setting of acute overdose.
Hematologic side effects of chlorpheniramine have included bone marrow suppression, thrombocytopenia, and aplastic anemia.[Ref]
Dermatologic side effects of acetaminophen have included erythematous skin rashes. 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).[Ref]
Respiratory side effects of acetaminophen have included a case of eosinophilic pneumonia.[Ref]
Cardiovascular side effects of acetaminophen have included two cases of hypotension.
Cardiovascular side effects of chlorpheniramine have included hypotension, tachycardia, and palpitations.[Ref]
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]
In the case of metabolic acidosis, causality is uncertain as more than one drug was ingested. The case of metabolic acidosis followed the ingestion of 75 grams of acetaminophen, 1.95 grams of aspirin, and a small amount of a liquid household cleaner. The patient also had a history of seizures which the authors reported may have contributed to an increased lactate level indicative of metabolic acidosis.[Ref]
Metabolic side effects of acetaminophen have included metabolic acidosis following a massive overdose.[Ref]
Few cases of dyskinesias and tremors, often of the face, have been reported in patients whose chronic use of chlorpheniramine extended over a period of 3 to 10 years. Some of these cases were only partially relieved by discontinuation of the drug. Haloperidol was successful in relieving symptoms.[Ref]
Nervous system side effects of chlorpheniramine have included depression resulting in drowsiness in 75% or more of treated patients. Dyskinesias have rarely been reported following chronic use of chlorpheniramine.[Ref]
Ocular side effects of chlorpheniramine have included blurred vision, diplopia, and dry eyes due to anticholinergic effects.[Ref]
Genitourinary side effects of chlorpheniramine have included dysuria, urinary hesitancy, and decreased urine flow.[Ref]
1. Gursoy M, Haznedaroglu IC, Celik I, Sayinalp N, Ozcebe OI, Dundar SV "Agranulocytosis, plasmacytosis, and thrombocytosis followed by a leukemoid reaction due to acute acetaminophen toxicity." Ann Pharmacother 30 (1996): 762-5
2. "Product Information. Coricidin (acetaminophen-chlorpheniramine)." Schering-Plough Healthcare Products, Memphis, TN.
3. Millet VM, Dreisbach M, Bryson YJ "Double-blind controlled study of central nervous system side effects of amantadine, rimantadine, and chlorpheniramine." Antimicrob Agents Chemother 21 (1982): 1-4
4. Bantz EW, Dolen WK, Chadwick EW, Nelson HS "Chronic chlorpheniramine therapy: subsensitivity, drug metabolism, and compliance." Ann Allergy 59 (1987): 341-6
5. Lee WM "Medical progress: drug-induced hepatotoxicity." N Engl J Med 333 (1995): 1118-27
6. Krause LB, Shuster S "A comparison of astemizole and chlorpheniramine in dermographic urticaria." Br J Dermatol 112 (1985): 447-53
7. Eguia L, Materson BJ "Acetaminophen-related acute renal failure without fulminant liver failure." Pharmacotherapy 17 (1997): 363-70
8. Kawada A, Hiruma M, Noguchi H, Ishibashi A "Fixed drug eruption induced by acetaminophen in a 12-year-old girl." Int J Dermatol 35 (1996): 148-9
9. Halevi A, BenAmitai D, Garty BZ "Toxic epidermal necrolysis associated with acetaminophen ingestion." Ann Pharmacother 34 (2000): 32-4
10. Bougie DW, Benito AI, Sanchez-Abarca LI, Torres R, Birenbaum J, Aster RH "Acute thrombocytopenia caused by sensitivity to the glucuronide conjugate of acetaminophen." Blood 109 (2007): 3608-9
11. Schuller DE, Turkewitz D "Adverse effects of antihistamines." Postgrad Med 79 (1986): 75-86
12. "Product Information. Chlortrimeton (chlorpheniramine)." Schering-Plough, Liberty Corner, NJ.
13. Brown G "Acetaminophen-induced hypotension." Heart Lung 25 (1996): 137-40
14. Koulouris Z, Tierney MG, Jones G "Metabolic acidosis and coma following a severe acetaminophen overdose." Ann Pharmacother 33 (1999): 1191-4
Not all side effects for Congestant may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.
More about Congestant (acetaminophen / chlorpheniramine)
- Other brands: Coricidin HBP Cold & Flu
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