Interactions between Chloramphenicol and Excedrin Sinus Headache
1 drug interaction and 19 additional warnings found for the following 2 drugs:
- chloramphenicol
- Excedrin Sinus Headache (acetaminophen/phenylephrine)
Drug interactions
Moderate drug interactions
Moderate:
chloramphenicol acetaminophen
Applies to: chloramphenicol and Excedrin Sinus Headache (acetaminophen / phenylephrine)
Monitor
Coadministration with acetaminophen (paracetamol) may alter chloramphenicol concentrations. The mechanism has not been fully elucidated, but pediatric data suggest increased chloramphenicol metabolism via enhanced hepatic glucuronidation during concomitant acetaminophen. In five children studied before and during oral acetaminophen 50 mg/kg/day, chloramphenicol clearance increased substantially (with decreased half-life, lower peak plasma concentration Cmax, and reduced AUC), and urinary chloramphenicol glucuronide excretion increased. In contrast, a small study in critically ill adults reported prolonged chloramphenicol half-life during concomitant intravenous acetaminophen, while other pediatric and adult reports have found no meaningful change or increased clearance.
Management
Until further information is available, the potential for altered pharmacologic effects of chloramphenicol should be considered during coadministration with acetaminophen. It may be advisable to monitor the pharmacologic response to chloramphenicol whenever acetaminophen is added to or withdrawn from therapy.
References (9)
- spika js, davis dj, martin sr, beharry k (1986) "Interaction between chloramphenicol and acetaminophen." Arch Dis Child, 61, p. 1121-4
- Stein CM, Thornhill DP, neill p, nyazema nz (1989) "Lack of effect of paracetamol on the pharmacokinetics of chloramphenicol." Br J Clin Pharmacol, 27, p. 262-4
- (2025) "Product Information. Anadin Paracetamol (paracetamol)." Haleon UK Trading Ltd
- Buchanan N, Moodley GP (1979) "Interaction between chloramphenicol and paracetamol." Br Med J, 2, p. 307-8
- (2025) "Product Information. Mersynonight (diphenhydramine-paracetamol)." Sanofi-Aventis Healthcare Pty Ltd T/A Sanofi Consumer Healthcare
- (2023) "Product Information. Acetaminophen (acetaminophen)." B. Braun of Canada Ltd
- (2026) "Product Information. Acetaminophen (acetaminophen)." Marlex Pharmaceuticals
- (2025) "Product Information. ANTIDOL INFANTIL (paracetamol)." LABORATORIOS CINFA, S.A.
- chemidex Pharma Ltd Chloramphenicol Capsules BP 250 mg https://www.medicines.org.uk/emc/product/12893/smpc/print
Food/lifestyle interactions
Major food/lifestyle interactions
Major:
acetaminophen Food/Lifestyle
Applies to: Excedrin Sinus Headache (acetaminophen / phenylephrine)
Generally avoid
Chronic, excessive consumption of alcohol may increase the risk of acetaminophen-induced hepatotoxicity, which has included rare cases of fatal hepatitis and frank hepatic failure requiring liver transplantation. The proposed mechanism is induction of hepatic microsomal enzymes during chronic alcohol use, which may result in accelerated metabolism of acetaminophen and increased production of potentially hepatotoxic metabolites.
Management
In general, chronic alcoholics should avoid regular or excessive use of acetaminophen. Alternative analgesic/antipyretic therapy may be appropriate in patients who consume three or more alcoholic drinks per day.
References (1)
- (2022) "Product Information. Acetaminophen (acetaminophen)." Camber Pharmaceuticals, Inc
Moderate food/lifestyle interactions
Moderate:
phenylephrine Caffeine
Applies to: Excedrin Sinus Headache (acetaminophen / phenylephrine)
Monitor
Coadministration of two or more sympathomimetic or noradrenergic agents may increase the risk of nervousness, irritability, tachycardia, and/or increased blood pressure. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic and/or noradrenergic agents, including norepinephrine transporter inhibitors. Additive increases in blood pressure and heart rate may occur due to enhanced peripheral sympathetic activity.
Management
Caution is advised if two or more sympathomimetic or noradrenergic agents are coadministered. Pulse and blood pressure should be closely monitored. Consultation with individual product labeling, as well as relevant institutional protocols, may be advisable for further guidance.
References (20)
- Rosenblatt JE, Lake CR, van Kammen DP, Ziegler MG, Bunney WE Jr (1979) "Interactions of amphetamine, pimozide, and lithium on plasma norepineophrine and dopamine-beta-hydroxylase in schizophrenic patients." Psychiatry Res, 1, p. 45-52
- Cavanaugh JH, Griffith JD, Oates JA (1970) "Effect of amphetamine on the pressor response to tyramine: formation of p-hydroxynorephedrine from amphetamine in man." Clin Pharmacol Ther, 11, p. 656
- (2001) "Product Information. Adderall (amphetamine-dextroamphetamine)." Shire Richwood Pharmaceutical Company Inc
- (2001) "Product Information. Tenuate (diethylpropion)." Aventis Pharmaceuticals
- (2001) "Product Information. Sanorex (mazindol)." Novartis Pharmaceuticals
- (2001) "Product Information. Focalin (dexmethylphenidate)." Mikart Inc
- (2024) "Product Information. Ephedrine (ephedrine)." Hameln Pharma Ltd
- (2023) "Product Information. Ephedrine Hydrochloride (ephedrine)." Wockhardt UK Ltd
- (2026) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
- (2025) "Product Information. Atomoxetine (atomoxetine)." Zentiva Pharma UK Ltd
- (2026) "Product Information. Atomoxetine (Apo) (atomoxetine)." Arrotex Pharmaceuticals Pty Ltd
- Angita Pharma, Inc (2026) AG-ATOMOXETINE Product Monograph (Health Canada) https://pdf.hres.ca/dpd_pm/00059014.PDF
- (2026) "Product Information. Boots Decongestant (Pseudoephedrine) (pseudoephedrine)." The Boots Company Plc
- (2023) "Product Information. Sinus and Nasal Decongestant (Trust) (pseudoephedrine)." Noumed Pharmaceuticals Pty Ltd
- (2019) "Product Information. Ephedrine (ephedrine)." Pfizer Australia Pty Ltd
- (2024) "Product Information. EPHEDrine Sulfate (ePHEDrine)." Amneal Pharmaceuticals LLC
- (2024) "Product Information. Lemsip Cough Max for Mucus Cough and Cold (guaifenesin/paracetamol/phenylephrine)." Reckitt Benckiser Healthcare (UK) Ltd
- emc (2026) Product information: sudafed plus blocked nose 1mg/50mg/ml nasal spray. https://www.medicines.org.uk/emc/product/14256/smpc?utm_source=chatgpt.com
- (2023) "Product Information. EPHEDrine Sulfate (ePHEDrine)." Baxter Corporation
- Neo Health (OTC) Pty Ltd (2026) Product information: pseudoephedrine hydrochloride-paracetamol capsules. https://www.ebs.tga.gov.au/ebs/picmi/picmirepository.nsf/pdf?OpenAgent&id=CP-2024-PI-02603-1&d=20260804172310101&d=20260827172310101
Disease interactions
17 potential interactions Applies to: 16 conditions, including Benign Prostatic Hyperplasia, Hyperthyroidism, Diabetes Mellitus, Liver Disease, and Dehydration.
Alcoholism
Major:
Excedrin Sinus Headache
The acetaminophen in Excedrin Sinus Headache has a major potential interaction with Alcoholism.
Chronic alcohol abusers may be at increased risk of hepatotoxicity during treatment with acetaminophen (APAP). Severe liver injury, including cases of acute liver failure resulting in liver transplant and death, has been reported in patients using acetaminophen. Therapy with acetaminophen should be administered cautiously, if at all, in patients who consume three or more alcoholic drinks a day. In general, patients should avoid drinking alcohol while taking acetaminophen-containing medications. Patients should be warned not to exceed the maximum recommended total daily dosage of acetaminophen (4 g/day in adults and children 12 years of age or older), and to read all prescription and over-the-counter medication labels to ensure they are not taking multiple acetaminophen-containing products, or check with a healthcare professional if they are unsure. They should also be advised to seek medical attention if they experience signs and symptoms of liver injury such as fever, rash, anorexia, nausea, vomiting, fatigue, right upper quadrant pain, dark urine, and jaundice.
Benign Prostatic Hyperplasia
Moderate:
Excedrin Sinus Headache
The phenylephrine in Excedrin Sinus Headache has a moderate potential interaction with Benign Prostatic Hyperplasia.
Sympathomimetic agents may cause or worsen urinary difficulty in patients with prostate enlargement due to smooth muscle contraction in the bladder neck via stimulation of alpha-1 adrenergic receptors. Therapy with sympathomimetic agents should be administered cautiously in patients with hypertrophy or neoplasm of the prostate.
Bone Marrow Depression/Low Blood Counts
Major:
chloramphenicol
Chloramphenicol has a major potential interaction with Bone Marrow Depression/Low Blood Counts.
Chloramphenicol may cause bone marrow depression and other hematologic toxicities, which can be irreversible or reversible. The former type is independent of dose and results in aplastic anemia with a high rate of mortality, generally from hemorrhage or infection. It has been reported following both systemic and topical administration of chloramphenicol and has an estimated incidence of 1 in 25,000 to 1 in 40,000 courses of therapy. Bone marrow aplasia or hypoplasia may occur after a single dose but more often develops weeks or months after the drug has been discontinued. A reversible myelosuppression occurs much more frequently and is characterized by anemia, vacuolation of red blood cells, decreased reticulocyte count, leukopenia, thrombocytopenia, increased serum iron concentrations, and increased serum iron-binding capacity. It is dose-dependent, occurring regularly at chloramphenicol dosages exceeding 4 g/day (in adults) or at plasma drug concentrations >= 25 mcg/mL, and usually responds to withdrawal of the drug. Therapy with chloramphenicol should be administered cautiously, if at all, in patients with preexisting blood dyscrasias and/or bone marrow depression. Complete blood counts and differential reticulocyte counts should be performed in all patients prior to initiating therapy and approximately every 2 days during therapy. Marked depression of blood counts and/or development of other hematologic abnormalities may be indication for withdrawal of chloramphenicol therapy.
Cardiovascular Conditions and Disorders
Major:
Excedrin Sinus Headache
The phenylephrine in Excedrin Sinus Headache has a major potential interaction with Cardiovascular Conditions and Disorders.
Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.
Cerebrovascular Insufficiency
Major:
Excedrin Sinus Headache
The phenylephrine in Excedrin Sinus Headache has a major potential interaction with Cerebrovascular Insufficiency.
Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.
Dehydration
Major:
Excedrin Sinus Headache
The acetaminophen in Excedrin Sinus Headache has a major potential interaction with Dehydration.
Acetaminophen is contraindicated in patients with severe hepatic impairment or severe active liver disease. Patients with hepatic impairment may be at increased risk of toxicity. Severe liver injury, including cases of acute liver failure and death, have been reported in patients using this drug. Clinical monitoring of hepatic function is recommended. Caution is advised if using acetaminophen in patients with chronic malnutrition or severe hypovolemia. Instruct patients to avoid drinking alcohol while taking acetaminophen-containing medications. Patients should be warned not to exceed the maximum recommended total daily dosage of acetaminophen (4 g/day in adults and children 12 years of age or older), and to read all prescription and over-the-counter medication labels to ensure they are not taking multiple acetaminophen-containing products, or check with a healthcare professional if they are unsure.
Diabetes Mellitus
Moderate:
Excedrin Sinus Headache
The phenylephrine in Excedrin Sinus Headache has a moderate potential interaction with Diabetes Mellitus.
Sympathomimetic agents may cause increases in blood glucose concentrations. These effects are usually transient and slight but may be significant with dosages higher than those normally recommended. Therapy with sympathomimetic agents should be administered cautiously in patients with diabetes mellitus. Closer monitoring of blood glucose concentrations may be appropriate.
Glaucoma/Intraocular Hypertension
Moderate:
Excedrin Sinus Headache
The phenylephrine in Excedrin Sinus Headache has a moderate potential interaction with Glaucoma/Intraocular Hypertension.
Sympathomimetic agents can induce transient mydriasis via stimulation of alpha-1 adrenergic receptors. In patients with anatomically narrow angles or narrow-angle glaucoma, pupillary dilation can provoke an acute attack. In patients with other forms of glaucoma, mydriasis may occasionally increase intraocular pressure. Therapy with sympathomimetic agents should be administered cautiously in patients with or predisposed to glaucoma, particularly narrow-angle glaucoma.
Hyperthyroidism
Major:
Excedrin Sinus Headache
The phenylephrine in Excedrin Sinus Headache has a major potential interaction with Hyperthyroidism.
Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.
Liver Disease
Major:
chloramphenicol
Chloramphenicol has a major potential interaction with Liver Disease.
Chloramphenicol is primarily inactivated by glucuronyl transferase in the liver and eliminated in the urine as both parent drug and metabolites. In adults with normal renal and hepatic function, only 5% to 15% of a dose of chloramphenicol is excreted unchanged by the kidney, but approximately 30% is excreted when chloramphenicol is administered intravenously as the sodium succinate ester. However, the fraction of drug excreted unchanged may be highly variable, especially in neonates and children. Therapy with chloramphenicol should be administered cautiously in patients with significantly impaired renal and/or hepatic function, since drug accumulation may occur in such patients. The dosage should be reduced based on the degree of impairment as well as plasma drug concentrations.
Major:
Excedrin Sinus Headache
The acetaminophen in Excedrin Sinus Headache has a major potential interaction with Liver Disease.
Acetaminophen is contraindicated in patients with severe hepatic impairment or severe active liver disease. Patients with hepatic impairment may be at increased risk of toxicity. Severe liver injury, including cases of acute liver failure and death, have been reported in patients using this drug. Clinical monitoring of hepatic function is recommended. Caution is advised if using acetaminophen in patients with chronic malnutrition or severe hypovolemia. Instruct patients to avoid drinking alcohol while taking acetaminophen-containing medications. Patients should be warned not to exceed the maximum recommended total daily dosage of acetaminophen (4 g/day in adults and children 12 years of age or older), and to read all prescription and over-the-counter medication labels to ensure they are not taking multiple acetaminophen-containing products, or check with a healthcare professional if they are unsure.
Malnourishment
Major:
Excedrin Sinus Headache
The acetaminophen in Excedrin Sinus Headache has a major potential interaction with Malnourishment.
Acetaminophen is contraindicated in patients with severe hepatic impairment or severe active liver disease. Patients with hepatic impairment may be at increased risk of toxicity. Severe liver injury, including cases of acute liver failure and death, have been reported in patients using this drug. Clinical monitoring of hepatic function is recommended. Caution is advised if using acetaminophen in patients with chronic malnutrition or severe hypovolemia. Instruct patients to avoid drinking alcohol while taking acetaminophen-containing medications. Patients should be warned not to exceed the maximum recommended total daily dosage of acetaminophen (4 g/day in adults and children 12 years of age or older), and to read all prescription and over-the-counter medication labels to ensure they are not taking multiple acetaminophen-containing products, or check with a healthcare professional if they are unsure.
Noninfectious Colitis
Major:
chloramphenicol
Chloramphenicol has a major potential interaction with Noninfectious Colitis.
Clostridioides difficile-associated diarrhea (CDAD), formerly pseudomembranous colitis, has been reported with almost all antibacterial drugs and may range from mild diarrhea to fatal colitis. The most common culprits include clindamycin and lincomycin. Antibacterial therapy alters the normal flora of the colon, leading to overgrowth of C difficile, whose toxins A and B contribute to CDAD development. Morbidity and mortality are increased with hypertoxin-producing strains of C difficile; these infections can be resistant to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea after antibacterial use. Since CDAD has been reported to occur more than 2 months after antibacterial use, careful medical history is necessary. Therapy with broad-spectrum antibacterials and other agents with significant antibacterial activity should be administered cautiously in patients with history of gastrointestinal disease, particularly colitis; pseudomembranous colitis (generally characterized by severe, persistent diarrhea and severe abdominal cramps, and sometimes associated with the passage of blood and mucus), if it occurs, may be more severe in these patients and may be associated with flares in underlying disease activity. Antibacterial drugs not directed against C difficile may need to be stopped if CDAD is suspected or confirmed. Appropriate fluid and electrolyte management, protein supplementation, antibacterial treatment of C difficile, and surgical evaluation should be started as clinically indicated.
Phenylketonuria
Moderate:
Excedrin Sinus Headache
The acetaminophen in Excedrin Sinus Headache has a moderate potential interaction with Phenylketonuria.
Several oral acetaminophen and acetaminophen-combination products, particularly flavored chewable tablets, contain the artificial sweetener, aspartame (NutraSweet). Aspartame is converted to phenylalanine in the gastrointestinal tract following ingestion. Chewable and effervescent formulations of acetaminophen products may also contain phenylalanine. The aspartame/phenylalanine content should be considered when these products are used in patients who must restrict their intake of phenylalanine (i.e. phenylketonurics).
Pheochromocytoma
Major:
Excedrin Sinus Headache
The phenylephrine in Excedrin Sinus Headache has a major potential interaction with Pheochromocytoma.
Sympathomimetic agents may cause adverse cardiovascular effects, particularly when used in high dosages and/or in susceptible patients. In cardiac tissues, these agents may produce positive chronotropic and inotropic effects via stimulation of beta- 1 adrenergic receptors. Cardiac output, oxygen consumption, and the work of the heart may be increased. In the peripheral vasculature, vasoconstriction may occur via stimulation of alpha-1 adrenergic receptors. Palpitations, tachycardia, arrhythmia, hypertension, reflex bradycardia, coronary occlusion, cerebral vasculitis, myocardial infarction, cardiac arrest, and death have been reported. Some of these agents, particularly ephedra alkaloids (ephedrine, ma huang, phenylpropanolamine), may also predispose patients to hemorrhagic and ischemic stroke. Therapy with sympathomimetic agents should generally be avoided or administered cautiously in patients with sensitivity to sympathomimetic amines, hyperthyroidism, or underlying cardiovascular or cerebrovascular disorders. These agents should not be used in patients with severe coronary artery disease or severe/uncontrolled hypertension.
Prostate Tumor, Benign
Moderate:
Excedrin Sinus Headache
The phenylephrine in Excedrin Sinus Headache has a moderate potential interaction with Prostate Tumor, Benign.
Sympathomimetic agents may cause or worsen urinary difficulty in patients with prostate enlargement due to smooth muscle contraction in the bladder neck via stimulation of alpha-1 adrenergic receptors. Therapy with sympathomimetic agents should be administered cautiously in patients with hypertrophy or neoplasm of the prostate.
Renal Dysfunction
Major:
chloramphenicol
Chloramphenicol has a major potential interaction with Renal Dysfunction.
Chloramphenicol is primarily inactivated by glucuronyl transferase in the liver and eliminated in the urine as both parent drug and metabolites. In adults with normal renal and hepatic function, only 5% to 15% of a dose of chloramphenicol is excreted unchanged by the kidney, but approximately 30% is excreted when chloramphenicol is administered intravenously as the sodium succinate ester. However, the fraction of drug excreted unchanged may be highly variable, especially in neonates and children. Therapy with chloramphenicol should be administered cautiously in patients with significantly impaired renal and/or hepatic function, since drug accumulation may occur in such patients. The dosage should be reduced based on the degree of impairment as well as plasma drug concentrations.
More resources
chloramphenicol
A total of 753 drugs are known to interact with chloramphenicol.
- Chloramphenicol is in the drug class miscellaneous antibiotics.
- Chloramphenicol is used to treat the following conditions:
Excedrin Sinus Headache
A total of 721 drugs are known to interact with Excedrin Sinus Headache.
- Excedrin sinus headache is in the drug class upper respiratory combinations.
- Excedrin sinus headache is used to treat the following conditions:
Drug Interaction Classification
| Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
| Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
| Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
| No interaction information available. |
Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.