Interactions between Comtrex Allergy Sinus Maximum Strength and Ethotoin
2 drug interactions and 39 additional warnings found for the following 2 drugs:
- Comtrex Allergy Sinus Maximum Strength (acetaminophen/chlorpheniramine/pseudoephedrine)
- ethotoin
Drug interactions
Moderate drug interactions
Moderate:
acetaminophen ethotoin
Applies to: Comtrex Allergy Sinus Maximum Strength (acetaminophen / chlorpheniramine / pseudoephedrine) and ethotoin
Monitor
Hydantoins may increase the potential hepatotoxicity of acetaminophen and decrease its pharmacologic effects. The mechanism may be related to induction of acetaminophen metabolism with consequent increase in hepatotoxic metabolites. This interaction is of greatest concern in cases of acetaminophen overdose.
Management
Monitoring of liver function is recommended. Patients should be advised to avoid large doses or prolonged use of acetaminophen.
References (6)
- Miners JO, Attwood J, Birkett DJ (1984) "Determinants of acetaminophen metabolism: effect of inducers and inhibitors of drug metabolism on acetaminophen's metabolic pathways." Clin Pharmacol Ther, 35, p. 480-6
- Minton NA, Henry JA, Frankel RJ (1988) "Fatal paracetamol poisoning in an epileptic." Hum Toxicol, 7, p. 33-4
- Bivins BA, Rapp RP, Griffen WO Jr, Blouin R, Bustrack J (1978) "Dopamine-phenytoin interaction. A cause of hypotension in the critically ill." Arch Surg, 113, p. 245-9
- Lorenzi M, Karam JH, Tsalikian E, Bohannon NV, Gerich JE, Forsham PH (1979) "Dopamine during alpha- or beta-adrenergic blockade in man. Hormonal, metabolic, and cardiovascular effects." J Clin Invest, 63, p. 310-7
- Prescott LF, Critchley JA (1983) "Drug interactions affecting analgesic toxicity." Am J Med, 75, p. 113-6
- Brackett CC, Bloch JD (2000) "Phenytoin as a possible cause of acetaminophen hepatotoxicity: Case report and review of the literature." Pharmacotherapy, 20, p. 229-33
Moderate:
chlorpheniramine ethotoin
Applies to: Comtrex Allergy Sinus Maximum Strength (acetaminophen / chlorpheniramine / pseudoephedrine) and ethotoin
Monitor
Toxic serum concentrations of phenytoin and involuntary movements have been reported during coadministration with chlorpheniramine. Symptoms resolved after chlorpheniramine was discontinued. The mechanism of this interaction is not known.
Management
Clinical monitoring of patient response, tolerance, and serum phenytoin concentrations is recommended. Patients should be advised to notify their physician if they experience symptoms of phenytoin toxicity (drowsiness, visual disturbances, change in mental status, nausea, or ataxia) or involuntary movements.
References (5)
- Pugh RN, Geddes AM, Yeoman WB (1975) "Interaction of phenytoin with chlorpheniramine." Br J Clin Pharmacol, 2, p. 173-5
- Ahmad S, Laidlaw J, Houghton GW, Richens A (1975) "Involuntary movements caused by phenytoin intoxication in epileptic patients." J Neurol Neurosurg Psychiatry, 38, p. 225-31
- (2006) "Product Information. Tussionex PennKinetic (chlorpheniramine-hydrocodone)." UCB Pharma Inc
- Cerner Multum, Inc. "UK Summary of Product Characteristics."
- (2017) "Product Information. TussiCaps (chlorpheniramine-hydrocodone)." ECR Pharmaceuticals
Food/lifestyle interactions
Major food/lifestyle interactions
Major:
acetaminophen Food/Lifestyle
Applies to: Comtrex Allergy Sinus Maximum Strength (acetaminophen / chlorpheniramine / pseudoephedrine)
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:
chlorpheniramine Food/Lifestyle
Applies to: Comtrex Allergy Sinus Maximum Strength (acetaminophen / chlorpheniramine / pseudoephedrine)
Generally avoid
Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.
Management
Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.
References (4)
- Warrington SJ, Ankier SI, Turner P (1986) "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology, 15, p. 31-7
- Gilman AG, eds., Nies AS, Rall TW, Taylor P (1990) "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: Pergamon Press Inc.
- (2012) "Product Information. Fycompa (perampanel)." Eisai Inc
- (2015) "Product Information. Rexulti (brexpiprazole)." Otsuka America Pharmaceutical, Inc.
Moderate:
ethotoin Food/Lifestyle
Applies to: ethotoin
Adjust dosing interval
Phenytoin bioavailability may decrease to subtherapeutic levels when the suspension is given concomitantly with enteral feedings. The mechanism may be related to phenytoin binding to substances in the enteral formula (e.g., calcium, protein) and/or binding to the tube lumen. Data have been conflicting and some studies have reported no changes in phenytoin levels, while others have reported significant reductions.
Monitor
Acute consumption of alcohol may increase plasma phenytoin levels. Chronic consumption of alcohol may decrease plasma phenytoin levels. The mechanism of this interaction is related to induction of phenytoin metabolism by ethanol during chronic administration. Other hydantoin derivatives may be similarly affected by ethanol.
Management
Some experts have recommended interrupting the feeding for 2 hours before and after the phenytoin dose, giving the phenytoin suspension diluted in water, and flushing the tube with water after administration; however, this method may not entirely avoid the interaction and is not always clinically feasible. Patients should be closely monitored for clinical and laboratory evidence of altered phenytoin efficacy and levels upon initiation and discontinuation of enteral feedings. Dosage adjustments or intravenous administration may be required until therapeutic serum levels are obtained. In addition, patients receiving phenytoin therapy should be warned about the interaction between phenytoin and ethanol and they should be advised to notify their physician if they experience worsening of seizure control or symptoms of toxicity, including drowsiness, visual disturbances, change in mental status, nausea, or ataxia.
References (16)
- Sandor P, Sellers EM, Dumbrell M, Khouw V (1981) "Effect of short- and long-term alcohol use on phenytoin kinetics in chronic alcoholics." Clin Pharmacol Ther, 30, p. 390-7
- Holtz L, Milton J, Sturek JK (1987) "Compatibility of medications with enteral feedings." JPEN J Parenter Enteral Nutr, 11, p. 183-6
- Sellers EM, Holloway MR (1978) "Drug kinetics and alcohol ingestion." Clin Pharmacokinet, 3, p. 440-52
- (2001) "Product Information. Dilantin (phenytoin)." Parke-Davis
- Doak KK, Haas CE, Dunnigan KJ, et al. (1998) "Bioavailability of phenytoin acid and phenytoin sodium with enteral feedings." Pharmacotherapy, 18, p. 637-45
- Rodman DP, Stevenson TL, Ray TR (1995) "Phenytoin malabsorption after jejunostomy tube delivery." Pharmacotherapy, 15, p. 801-5
- Au Yeung SC, Ensom MH (2000) "Phenytoin and enteral feedings: does evidence support an interaction?" Ann Pharmacother, 34, p. 896-905
- Ozuna J, Friel P (1984) "Effect of enteral tube feeding on serum phenytoin levels." J Neurosurg Nurs, 16, p. 289-91
- Faraji B, Yu PP (1998) "Serum phenytoin levels of patients on gastrostomy tube feeding." J Neurosci Nurs, 30, p. 55-9
- Marvel ME, Bertino JS (1991) "Comparative effects of an elemental and a complex enteral feeding formulation on the absorption of phenytoin suspension." JPEN J Parenter Enteral Nutr, 15, p. 316-8
- Fleisher D, Sheth N, Kou JH (1990) "Phenytoin interaction with enteral feedings administered through nasogastric tubes." JPEN J Parenter Enteral Nutr, 14, p. 513-6
- Haley CJ, Nelson J (1989) "Phenytoin-enteral feeding interaction." DICP, 23, p. 796-8
- Guidry JR, Eastwood TF, Curry SC (1989) "Phenytoin absorption in volunteers receiving selected enteral feedings." West J Med, 150, p. 659-61
- Krueger KA, Garnett WR, Comstock TJ, Fitzsimmons WE, Karnes HT, Pellock JM (1987) "Effect of two administration schedules of an enteral nutrient formula on phenytoin bioavailability." Epilepsia, 28, p. 706-12
- Cerner Multum, Inc. "UK Summary of Product Characteristics."
- Cerner Multum, Inc. "Australian Product Information."
Moderate:
pseudoephedrine Caffeine
Applies to: Comtrex Allergy Sinus Maximum Strength (acetaminophen / chlorpheniramine / pseudoephedrine)
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
35 potential interactions Applies to: 27 conditions, including Depression, Vitamin D Deficiency, Asthma, Benign Prostatic Hyperplasia, and COPD.
Abnormal Glucose Tolerance
Moderate:
ethotoin
Ethotoin has a moderate potential interaction with Abnormal Glucose Tolerance.
Phenytoin, particularly in high dosages, may cause hyperglycemia by inhibiting insulin release. The drug may also raise serum glucose levels in diabetic patients. Therapy with phenytoin should be administered cautiously in patients with diabetes mellitus, glucose intolerance, or a predisposition to hyperglycemia. Patients with diabetes mellitus should be monitored more closely during phenytoin therapy, and their antidiabetic regimen adjusted accordingly. The same precautions should also be observed with other hydantoin anticonvulsants (i.e. ethotoin and mephenytoin) because of their structural and pharmacological similarities to phenytoin.
Alcoholism
Major:
Comtrex Allergy Sinus Maximum Strength
The acetaminophen in Comtrex Allergy Sinus Maximum Strength 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.
Anemia, Folate Deficiency
Moderate:
ethotoin
Ethotoin has a moderate potential interaction with Anemia, Folate Deficiency.
Hydantoin anticonvulsants may interfere with folate metabolism and precipitate macrocytosis and megaloblastic anemia, which usually respond to folic acid therapy. These reactions have been fairly uncommon but may be of concern in patients with megaloblastic anemia or folate deficiency receiving hydantoin therapy.
Asthma
Moderate:
Comtrex Allergy Sinus Maximum Strength
The chlorpheniramine in Comtrex Allergy Sinus Maximum Strength has a moderate potential interaction with Asthma.
It has been suggested that the anticholinergic effect of antihistamines may reduce the volume and cause thickening of bronchial secretions, resulting in obstruction of respiratory tract. Some manufacturers and clinicians recommend that therapy with antihistamines be administered cautiously in patients with asthma or chronic obstructive pulmonary disease.
Benign Prostatic Hyperplasia
Moderate:
Comtrex Allergy Sinus Maximum Strength
The pseudoephedrine in Comtrex Allergy Sinus Maximum Strength 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:
ethotoin
Ethotoin has a major potential interaction with Bone Marrow Depression/Low Blood Counts.
Hematologic toxicities have been associated with the use of hydantoin anticonvulsants, particularly mephenytoin. Thrombocytopenia, leukopenia, neutropenia, agranulocytosis, pancytopenia and, rarely, hemolytic anemia, aplastic anemia and pure red cell aplasia have been reported. Therapy with hydantoin anticonvulsants should be administered cautiously in patients with preexisting blood dyscrasias and/or bone marrow depression. Complete blood counts, including platelets, should be performed prior to initiating therapy and regularly for several months thereafter. For mephenytoin, the manufacturer recommends performing counts after 2 weeks on a low dosage, after another 2 weeks when full dosage is reached, then monthly for a year, and every 3 months thereafter. Marked depression of blood counts may be indication for withdrawal of hydantoin therapy.
Cardiovascular Conditions and Disorders
Major:
Comtrex Allergy Sinus Maximum Strength
The pseudoephedrine in Comtrex Allergy Sinus Maximum Strength 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.
Moderate:
Comtrex Allergy Sinus Maximum Strength
The chlorpheniramine in Comtrex Allergy Sinus Maximum Strength has a moderate potential interaction with Cardiovascular Conditions and Disorders.
Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.
Cerebrovascular Insufficiency
Major:
Comtrex Allergy Sinus Maximum Strength
The pseudoephedrine in Comtrex Allergy Sinus Maximum Strength 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.
COPD
Moderate:
Comtrex Allergy Sinus Maximum Strength
The chlorpheniramine in Comtrex Allergy Sinus Maximum Strength has a moderate potential interaction with COPD.
It has been suggested that the anticholinergic effect of antihistamines may reduce the volume and cause thickening of bronchial secretions, resulting in obstruction of respiratory tract. Some manufacturers and clinicians recommend that therapy with antihistamines be administered cautiously in patients with asthma or chronic obstructive pulmonary disease.
Dehydration
Major:
Comtrex Allergy Sinus Maximum Strength
The acetaminophen in Comtrex Allergy Sinus Maximum Strength 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.
Depression
Moderate:
ethotoin
Ethotoin has a moderate potential interaction with Depression.
Antiepileptic drugs (AEDs) have been associated with an increased risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Pooled analyses of 199 placebo-controlled clinical studies involving the use of 11 different AEDs showed that patients receiving AEDs had approximately twice the risk of suicidal thinking or behavior compared to patients receiving placebo. AEDs should be administered cautiously in patients with depression or other psychiatric disorders; phentermine-topiramate should be avoided in patients with history of suicidal attempts or active suicidal ideation. The risk of suicidal thoughts and behavior should be carefully assessed against the risk of untreated illness, bearing in mind that epilepsy and many other conditions for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Patients, caregivers, and families should be alert to the emergence or worsening of signs and symptoms of depression, any unusual changes in mood or behavior, or the emergence of suicidal thoughts or behavior. If patients have symptoms of suicidal ideation or behavior, a dosage reduction or treatment discontinuation should be considered.
Diabetes Mellitus
Moderate:
Comtrex Allergy Sinus Maximum Strength
The pseudoephedrine in Comtrex Allergy Sinus Maximum Strength 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.
Moderate:
ethotoin
Ethotoin has a moderate potential interaction with Diabetes Mellitus.
Phenytoin, particularly in high dosages, may cause hyperglycemia by inhibiting insulin release. The drug may also raise serum glucose levels in diabetic patients. Therapy with phenytoin should be administered cautiously in patients with diabetes mellitus, glucose intolerance, or a predisposition to hyperglycemia. Patients with diabetes mellitus should be monitored more closely during phenytoin therapy, and their antidiabetic regimen adjusted accordingly. The same precautions should also be observed with other hydantoin anticonvulsants (i.e. ethotoin and mephenytoin) because of their structural and pharmacological similarities to phenytoin.
Folic Acid/Cyanocobalamin Deficiency
Moderate:
ethotoin
Ethotoin has a moderate potential interaction with Folic Acid/Cyanocobalamin Deficiency.
Hydantoin anticonvulsants may interfere with folate metabolism and precipitate macrocytosis and megaloblastic anemia, which usually respond to folic acid therapy. These reactions have been fairly uncommon but may be of concern in patients with megaloblastic anemia or folate deficiency receiving hydantoin therapy.
Gastrointestinal Obstruction
Moderate:
Comtrex Allergy Sinus Maximum Strength
The pseudoephedrine in Comtrex Allergy Sinus Maximum Strength has a moderate potential interaction with Gastrointestinal Obstruction.
The extended-release formulation of pseudoephedrine (Sudafed 24 Hour) contains a non-deformable material. There have been rare reports of obstructive symptoms in patients with known strictures following the ingestion of similar sustained-release products. Therapy with the extended-release formulation of pseudoephedrine should be administered cautiously in patients with preexisting severe gastrointestinal narrowing or obstruction, whether pathologic or iatrogenic.
Moderate:
Comtrex Allergy Sinus Maximum Strength
The chlorpheniramine in Comtrex Allergy Sinus Maximum Strength has a moderate potential interaction with Gastrointestinal Obstruction.
Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.
Glaucoma/Intraocular Hypertension
Moderate:
Comtrex Allergy Sinus Maximum Strength
The pseudoephedrine in Comtrex Allergy Sinus Maximum Strength 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.
Moderate:
Comtrex Allergy Sinus Maximum Strength
The chlorpheniramine in Comtrex Allergy Sinus Maximum Strength has a moderate potential interaction with Glaucoma/Intraocular Hypertension.
Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.
Hyperthyroidism
Major:
Comtrex Allergy Sinus Maximum Strength
The pseudoephedrine in Comtrex Allergy Sinus Maximum Strength 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.
Moderate:
Comtrex Allergy Sinus Maximum Strength
The chlorpheniramine in Comtrex Allergy Sinus Maximum Strength has a moderate potential interaction with Hyperthyroidism.
Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.
Hypotension
Moderate:
Comtrex Allergy Sinus Maximum Strength
The chlorpheniramine in Comtrex Allergy Sinus Maximum Strength has a moderate potential interaction with Hypotension.
Antihistamines may infrequently cause cardiovascular adverse effects related to their anticholinergic and local anesthetic (quinidine-like) activities. Tachycardia, palpitation, ECG changes, arrhythmias, hypotension, and hypertension have been reported. Although these effects are uncommon and usually limited to overdosage situations, the manufacturers and some clinicians recommend that therapy with antihistamines be administered cautiously in patients with cardiovascular disease, hypertension, and/or hyperthyroidism.
Liver Disease
Major:
Comtrex Allergy Sinus Maximum Strength
The acetaminophen in Comtrex Allergy Sinus Maximum Strength 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.
Major:
ethotoin
Ethotoin has a major potential interaction with Liver Disease.
Hydantoin anticonvulsants are primarily metabolized by the liver. Both metabolic activity and plasma protein binding may be significantly altered in patients with liver disease, resulting in elevated drug levels (total and unbound fraction) and increased risk of toxicity. Therapy with hydantoin anticonvulsants should be administered cautiously in patients with impaired hepatic function. Reduced dosages and slower titration may be necessary. In addition, periodic monitoring of liver function is recommended, since the use of anticonvulsants, including hydantoins, has been associated with hepatotoxicity related to drug hypersensitivity. Hepatic failure and death have occurred. Hydantoin therapy should be discontinued and not readministered if evidence of liver damage is observed and felt to be drug-related.
Moderate:
Comtrex Allergy Sinus Maximum Strength
The chlorpheniramine in Comtrex Allergy Sinus Maximum Strength has a moderate potential interaction with Liver Disease.
Limited pharmacokinetic data are available for the older, first-generation antihistamines. Many appear to be primarily metabolized by the liver, and both parent drugs and metabolites are excreted in the urine. Patients with renal and/or liver disease may be at greater risk for adverse effects from antihistamines due to drug and metabolite accumulation. Therapy with antihistamines should be administered cautiously in such patients. Lower initial dosages may be appropriate.
Malnourishment
Major:
Comtrex Allergy Sinus Maximum Strength
The acetaminophen in Comtrex Allergy Sinus Maximum Strength 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.
Phenylketonuria
Moderate:
Comtrex Allergy Sinus Maximum Strength
The pseudoephedrine in Comtrex Allergy Sinus Maximum Strength has a moderate potential interaction with Phenylketonuria.
Chewable products frequently may contain aspartame, which is metabolized in the gastrointestinal tract to phenylalanine. Sudafed (brand of pseudoephedrine) chewable 15 mg tablets provide the equivalent of 0.78 mg of phenylalanine per each tablet. The aspartame/phenylalanine content should be considered when this and similar products are used in patients who must restrict their intake of phenylalanine (i.e. phenylketonurics).
Moderate:
Comtrex Allergy Sinus Maximum Strength
The acetaminophen in Comtrex Allergy Sinus Maximum Strength 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:
Comtrex Allergy Sinus Maximum Strength
The pseudoephedrine in Comtrex Allergy Sinus Maximum Strength 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.
Porphyria
Major:
ethotoin
Ethotoin has a major potential interaction with Porphyria.
The use of phenytoin has rarely been associated with exacerbation of porphyria. Therapy with phenytoin should be administered cautiously in patients with porphyria. The same precaution should also be observed with other hydantoin anticonvulsants (i.e. ethotoin and mephenytoin) because of their structural and pharmacological similarities to phenytoin.
Prostate Tumor, Benign
Moderate:
Comtrex Allergy Sinus Maximum Strength
The pseudoephedrine in Comtrex Allergy Sinus Maximum Strength 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.
Psychosis
Moderate:
ethotoin
Ethotoin has a moderate potential interaction with Psychosis.
Antiepileptic drugs (AEDs) have been associated with an increased risk of suicidal thoughts or behavior in patients taking these drugs for any indication. Pooled analyses of 199 placebo-controlled clinical studies involving the use of 11 different AEDs showed that patients receiving AEDs had approximately twice the risk of suicidal thinking or behavior compared to patients receiving placebo. AEDs should be administered cautiously in patients with depression or other psychiatric disorders; phentermine-topiramate should be avoided in patients with history of suicidal attempts or active suicidal ideation. The risk of suicidal thoughts and behavior should be carefully assessed against the risk of untreated illness, bearing in mind that epilepsy and many other conditions for which AEDs are prescribed are themselves associated with morbidity and mortality and an increased risk of suicidal thoughts and behavior. Patients, caregivers, and families should be alert to the emergence or worsening of signs and symptoms of depression, any unusual changes in mood or behavior, or the emergence of suicidal thoughts or behavior. If patients have symptoms of suicidal ideation or behavior, a dosage reduction or treatment discontinuation should be considered.
Renal Dysfunction
Moderate:
Comtrex Allergy Sinus Maximum Strength
The chlorpheniramine in Comtrex Allergy Sinus Maximum Strength has a moderate potential interaction with Renal Dysfunction.
Limited pharmacokinetic data are available for the older, first-generation antihistamines. Many appear to be primarily metabolized by the liver, and both parent drugs and metabolites are excreted in the urine. Patients with renal and/or liver disease may be at greater risk for adverse effects from antihistamines due to drug and metabolite accumulation. Therapy with antihistamines should be administered cautiously in such patients. Lower initial dosages may be appropriate.
Urinary Retention
Moderate:
Comtrex Allergy Sinus Maximum Strength
The chlorpheniramine in Comtrex Allergy Sinus Maximum Strength has a moderate potential interaction with Urinary Retention.
Antihistamines often have anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with antihistamines should be administered cautiously, if at all, in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Conventional, first-generation antihistamines such as the ethanolamines (bromodiphenhydramine, carbinoxamine, clemastine, dimenhydrinate, diphenhydramine, doxylamine, phenyltoloxamine) tend to exhibit substantial anticholinergic effects. In contrast, the newer, relatively nonsedating antihistamines (e.g., cetirizine, fexofenadine, loratadine) reportedly have low to minimal anticholinergic activity at normally recommended dosages and may be appropriate alternatives.
Vitamin D Deficiency
Moderate:
ethotoin
Ethotoin has a moderate potential interaction with Vitamin D Deficiency.
Phenytoin may interfere with vitamin D metabolism. Hypocalcemia and osteomalacia have been reported. Therapy with phenytoin should be administered cautiously in patients with preexisting vitamin D deficiency. The same precaution should also be observed with other hydantoin anticonvulsants (i.e. ethotoin and mephenytoin) because of their structural and pharmacological similarities to phenytoin.
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Comtrex Allergy Sinus Maximum Strength
A total of 961 drugs are known to interact with Comtrex Allergy Sinus Maximum Strength.
- Comtrex allergy sinus maximum strength is in the drug class upper respiratory combinations.
- Comtrex allergy sinus maximum strength is used to treat the following conditions:
ethotoin
A total of 412 drugs are known to interact with ethotoin.
- Ethotoin is in the drug class hydantoin anticonvulsants.
- Ethotoin 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
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