Drug Interactions between amiodarone and Feminine Lax
This report displays the potential drug interactions for the following 2 drugs:
- amiodarone
- Feminine Lax (docusate/phenolphthalein)
Interactions between your drugs
amiodarone phenolphthalein
Applies to: amiodarone and Feminine Lax (docusate / phenolphthalein)
MONITOR: Bowel cleansing as well as overuse of certain laxatives may cause electrolyte loss and increase the risk of torsade de pointes ventricular arrhythmia in patients treated with drugs that prolong the QT interval. Electrolyte disturbances including hypokalemia and hypomagnesemia have been reported with laxative abuse and are known risk factors for torsade de pointes associated with QT interval prolongation.
MANAGEMENT: Patients treated with drugs that prolong the QT interval should exercise caution when self-medicating with laxatives. The recommended dosage and duration of use should not be exceeded. Patients treated with lactulose for more than six months should be monitored periodically for electrolyte imbalance. Patients should be advised to seek prompt medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, lightheadedness, fainting, palpitation, irregular heart rhythm, shortness of breath, or syncope.
References
- Chin RL (1998) "Laxative-induced hypokalemia." Ann Emerg Med, 32, p. 517-8
- Muller-Lissner SA (1993) "Adverse effects of laxatives: fact and fiction." Pharmacology, 47, p. 138-45
- Cerner Multum, Inc. "UK Summary of Product Characteristics."
- Canadian Pharmacists Association (2006) e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink
- Cerner Multum, Inc. "Australian Product Information."
- Schaefer DC, Cheskin LJ (1998) "Constipation in the elderly." Am Fam Physician, 58, p. 907-14
phenolphthalein docusate
Applies to: Feminine Lax (docusate / phenolphthalein) and Feminine Lax (docusate / phenolphthalein)
GENERALLY AVOID: Docusate may increase the toxicity of phenolphthalein by increasing intestinal absorption of the drug.
MANAGEMENT: Concomitant use of docusate and phenolphthalein should be avoided.
References
- (2001) "Product Information. Colace (docusate)." Roberts Pharmaceutical Corporation
Drug and food interactions
amiodarone food
Applies to: amiodarone
GENERALLY AVOID: Grapefruit juice may significantly increase the plasma concentrations of orally administered amiodarone. The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits. In 11 nonsmoking, healthy volunteers, grapefruit juice (300 mL with drug administration, then 3 hours and 9 hours later) increased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of amiodarone (17 mg/kg single dose) by 84% and 50%, respectively, compared to water. Formation of the pharmacologically active metabolite, N-desethylamiodarone (N-DEA), was completely inhibited. Clinically, this interaction can lead to altered efficacy of amiodarone, since antiarrhythmic properties of amiodarone and N-DEA appear to differ. In the study, mean increases in PR and QTc intervals of 17.9% and 11.3%, respectively, were observed 6 hours postdose with water, while increases of 10.2% and 3.3%, respectively, were observed after administration with grapefruit juice.
ADJUST DOSING INTERVAL: Food increases the rate and extent of absorption of amiodarone. The mechanism appears to involve the effect of food-induced physiologic changes on drug release from its formulation. In 30 healthy volunteers, administration of a single 600 mg dose of amiodarone following a high-fat meal resulted in a Cmax and AUC that were 3.8 and 2.4 times the respective values under fasting conditions. The time to reach peak plasma concentration (Tmax) was decreased by 37%, indicating an increased rate of absorption. Mean Cmax and AUC for the active metabolite, N-DEA, also increased by 32% and 55%, respectively, but there was no change in the Tmax.
MANAGEMENT: Patients treated with oral amiodarone should avoid consumption of grapefruits and grapefruit juice. In addition, oral amiodarone should be administered consistently with regard to meals.
References
- (2002) "Product Information. Cordarone (amiodarone)." Wyeth-Ayerst Laboratories
- Libersa CC, Brique SA, Motte KB, et al. (2000) "Dramatic inhibition of amiodarone metabolism induced by grapefruit juice." Br J Clin Pharmacol, 49, p. 373-8
- Meng X, Mojaverian P, Doedee M, Lin E, Weinryb I, Chiang ST, Kowey PR (2001) "Bioavailability of Amiodarone tablets administered with and without food in healthy subjects." Am J Cardiol, 87, p. 432-5
Therapeutic duplication warnings
No 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.
See also
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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