Amiodarone interactions

Siegmund JB, Wilson JH, Imhoff TE. Amiodarone interaction with lidocaine. J Cardiovasc Pharmacol 1993 21 513-515. 

Freitag D, Bebee R, Sunderland B. Digoxin-quinidine and digoxin-amiodarone interactions Frequency of occurrence and monitoring in Australian repatriation hospitals. J Clin Pharm Ther 1995 20 179-83. 

Boutitie F, Boissel JP, ConnoUy SJ, Camm AJ, Cairns JA, Juhan DG, Gent M, Janse MJ, Dorian P, Frangin G. Amiodarone interaction with beta-blockers analysis of the merged EMIAT (European Myocardial Infarct Amiodarone Trial) and CAMIAT (Canadian Amiodarone Myocardial Infarction Trial) databases. The EMIAT and CAMIAT Investigators. Circulation 1999 99(17) 2268-75. 

Robinson K, Johnston A, Walker S, Mulrow JP, McKenna WJ, Holt DW. The digoxin-amiodarone interaction. Cardiovasc Drugs Ther 1989 3 25-28. 

Other authors have reported this interaction, and suggest reducing the flecainide dosage by between one-third to one-half when amiodarone is added. " Another study found that amiodarone raised steady-state flecainide plasma levels by 37% in extensive metabolisers, and 55% in poor me-tabolisers of dextromethorphan (a probe drug for CYP2D6 activity). In a later report of this study the authors concluded that these differences were nof clinically imporfanf, and that CYP2D6 phenotype does not affect the extent of the flecainide-amiodarone interaction. An isolated report describes torsade de pointes in a patient on amiodarone when given flecainide. ... 

Matsumoto K, Ueno K, Nakabayashi T, Komamura K, Kamakura S, Miyatake K. Amiodarone interaction time differences widi warfarin and digoxin.JP/iamiT ec/mo/(2003) 19, 83-... 

Fenster PE, White NW, Hanson CD. Pharmacokinetic evaluation of the digoxin-amiodarone interaction. J Am Coll CarcMol (1985) 5, 108-12. 

Chitwood KK, Abdul-Haqq AJ, Heim-Duthoy KL. Cyclosporine-amiodarone interaction. Ann Pharmacother ( 993) 27, 569-71. 

Ricuarte B, Guirguis A, Taylor HC, Zabri ie D. Simvastatin-amiodarone interaction result-ii in rhabdcmyolysis, azotemia, and possible hepatotoxicity. Ann Pharmacother (2006) 40, 753-7. 

An amiodarone interaction was also indicated in a retrospective cohort study of patients over 65 years of age on at least six continuous months of warfarin therapy. The two cohorts, patients receiving amiodarone or not, were matched based on age, gender, year of cohort entry and a high-dimensional propensity score. The initiation of amiodarone among older patients taking warfarin was associated with a more than twofold increase in the risk of hospitalization for haemorrhage with a relatively high fatality rate [12 ]. 

Fig. 20.13. Potential H-bonding energy, released upon interaction with the transmembrane domains of P-gp (in arbitrary energy units, EU) for progesterone (1), propranolol (2), amitriptyline (3), diltiazem (4), amiodarone (5), colchicine (7), gramicidin S (8), daunorubicin (9), vinblastine (10), cyclosporin A, in comparison with verapamil...

The drug is also a highly lipophilic base and accumulates in a number of tissues including the lung. This combination of extreme physicochemical properties can result in more specific interactions such as the condition of phospholipidosis (increase in total lung phospholipids) caused by inhibition of phospholipid breakdown [4]. The medicinal chemist has to decide if extreme lipophilicity and the presence of iodine are essential for activity and, in the case of amiodarone, proven clinical efficacy or whether alternative structures are possible. 

Drugs that may affect amiodarone include hydantoins, cholestyramine, fluoroquinolones, rifamycins, ritonavir, and cimetidine. Drugs that may be affected by amiodarone include anticoagulants, beta-blockers, calcium channel blockers, cyclosporine, dextromethorphan, digoxin, disopyramide, fentanyl, flecainide, hydantoins, lidocaine, methotrexate, procainamide, quinidine, and theophylline. Drug/Lab test interactions Amiodarone alters the results of thyroid function tests, causing an increase in serum T4 and serum reverse T3 levels and a decline in... 

Hypersensitivity to any component of the product. Coadministration of nelfinavir is contraindicated with drugs that are highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events (eg, amiodarone, quinidine, ergot derivatives, pimozide, midazolam, triazolam, lovastatin, simvastatin see Drug Interactions). 

Drug interactions Serious and/or life-threatening drug interactions could occur between amprenavir and amiodarone, lidocaine (systemic), tricyclic antidepressants, and quinidine. Concentration monitoring of these agents is recommended if these agents are used concomitantly with amprenavir. 

Dextromethorphan (Mediquell, Benylin DM, PediaCare 1, Delsym, Others) [OTC] [Antitussive] Uses Control nonproductive cough Action Suppresses medullary cough center Dose Adults. 10-30 mg PO q4h PRN (max 120 mg/24 h) Peds. 2-6 y 2.5-7.5 mg q4-8h (max 30 mg/24 h) 7-12 y 5-10 mg q4-8h (max 60 mg/24/h) Caution [C, /-] Not for persistent or chronic cough Contra < 2 y. Disp Caps, lozenges, syrup, Liq SE GI disturbances Interactions T Effects W/ amiodarone, fluoxetine, quinidine, terbinafme T risk of serotonin synd Wf sibutramine, MAOIs T CNS depression Wf antihistamines, antidepressants, sedative, opioids, EtOH EMS Will not affect cough caused by asthma,... 

Ezetimibe/Simvastatin (Vytorin) [Antilipemic/HMG CoA Reductose Inhibitor] Uses H rp cholest olemia Action X Absorption of cholesterol phytost ol w/ HMG-CoA reductase inhibitor Dose 10/10-10/80 mg/d PO w/ cyclosporine or danazol 10/10 mg/d max w/ amio-darone or verapamil 10/20 mg/d max -1- w/ sev e renal insuff Caution [X, -] w/ CYP3A4 inhibitors (Table VI-8), gemfibrozil, niacin >lg/d, danazol, amiodarone, verapamil Contra PRG/lactation livCT Dz, t LFTs Disp Tabs SE HA, GI upset, myalgia, myopathy (muscle pain, weakness, or tendOTiess w/ CK 10 x ULN, rhab-domyolysis), Hep, Infxn Interactions t Risk of myopathy W7 clarithromycin, erythromycin, itraconazole, ketoconazole EMS None OD Sxs unknown symptomatic and supportive... 

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