Drug Interaction Report
4 potential interactions and/or warnings found for the following 2 drugs:
- digoxin
- Fedahist Timecaps (chlorpheniramine / pseudoephedrine)
Interactions between your drugs
digoxin pseudoephedrine
Applies to: digoxin, Fedahist Timecaps (chlorpheniramine / pseudoephedrine)
MONITOR: The concomitant use of sympathomimetic agents and cardiac glycosides may increase the risk of cardiac arrhythmias. The mechanism of this interaction is not known. Increased ectopic pacemaker activity has been reported to occur in patients taking digoxin in combination with pseudoephedrine.
MANAGEMENT: Caution should be exercised if these two drugs are coadministered. Electrocardiogram monitoring (ECG) is recommended. The use of epinephrine (adrenaline) with high doses of digitalis glycosides is not recommended.
References
- (2001) "Product Information. Isuprel (isoproterenol)." Sanofi Winthrop Pharmaceuticals
- (2001) "Product Information. Lanoxin (digoxin)." Glaxo Wellcome
- (2022) "Product Information. EPINEPHrine Hydrochloride (EPINEPHrine)." Abbott Pharmaceutical
- (2001) "Product Information. Claritin-D (loratadine-pseudoephedrine)." Schering-Plough
- (2001) "Product Information. Allegra-D (fexofenadine-pseudoephedrine)." Chattem Consumer Products
- Cerner Multum, Inc. "UK Summary of Product Characteristics."
- Cerner Multum, Inc. "Australian Product Information."
Drug and food interactions
chlorpheniramine food
Applies to: Fedahist Timecaps (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
- 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 American Pharmaceuticals Inc
pseudoephedrine food
Applies to: Fedahist Timecaps (chlorpheniramine / pseudoephedrine)
MONITOR: Coadministration of two or more sympathomimetic agents may increase the risk of adverse effects such as nervousness, irritability, and increased heart rate. Central nervous system (CNS) stimulants, particularly amphetamines, can potentiate the adrenergic response to vasopressors and other sympathomimetic agents. 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 agents are coadministered. Pulse and blood pressure should be closely monitored.
References
- 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
- (2002) "Product Information. Strattera (atomoxetine)." Lilly, Eli and Company
digoxin food
Applies to: digoxin
Administration of digoxin with a high-fiber meal has been shown to decrease its bioavailability by almost 20%. Fiber can sequester up to 45% of the drug when given orally. Patients should be advised to maintain a regular diet without significant fluctuation in fiber intake while digoxin is being titrated.
Grapefruit juice may modestly increase the plasma concentrations of digoxin. The mechanism is increased absorption of digoxin due to mild inhibition of intestinal P-glycoprotein by certain compounds present in grapefruits. In 12 healthy volunteers, administration of grapefruit juice with and 30 minutes before, as well as 3.5, 7.5, and 11.5 hours after a single digoxin dose (0.5 mg) increased the mean area under the plasma concentration-time curve (AUC) of digoxin by just 9% compared to administration with water. Moreover, P-glycoprotein genetic polymorphism does not appear to influence the magnitude of the effects of grapefruit juice on digoxin. Thus, the interaction is unlikely to be of clinical significance.
References
- Darcy PF (1995) "Nutrient-drug interactions." Adverse Drug React Toxicol Rev, 14, p. 233-54
- Becquemont L, Verstuyft C, Kerb R, et al. (2001) "Effect of grapefruit juice on digoxin pharmacokinetics in humans." Clin Pharmacol Ther, 70, p. 311-6
Therapeutic duplication warnings
No duplication warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
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. |
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