Diltiazem Amiodarone

Antibacterials Ciprofloxacin Erythromycin Isoniazid Antidepressants Flnoxetine Huvoxamine Paroxetine Antifungal drugs Fluconazole Itraconazole Ketoconazole Miconazole Antiviral drugs Indinavir Ritonavir Saquinavir Cardiovascular drugs Amiodarone Diltiazem Quinidine Verapamil... 

Qomethiazole Amiodarone Amiodarone Diltiazem Grapefruit Juice Ritonavir"4... 

Kim MH, Rachwal W, McHale C, Bruckman D, Decena BF, Rushan P, MoratfyF, Eagle KA. Effect of amiodarone diltiazem beta blocker on frequency of atrial fibrill on, length of ho italization, and hospital costs after coronary artery bypass graftii. Am J Carrol (2002) 89,1126-28... 

In the UK, the manufacturers recommend that the dose of eplerenone should not exceed 25 mg daily in patients taking mild to moderate CYP3A4 inhibitors such as amiodarone, diltiazem, erythromycin, fluconazole, saquinavir and verapamil. In the US, the manufacturer recommends that the starting dose for hypertension should be reduced to 25 mg daily for patients taking these drugs. This seems a sensible precaution. However, note that in many cases erythromycin appears to be a more potent inhibitor of CYP3A4 than clarithromycin (and certainly the other moderate CYP3A4 inhibitors listed above), and so extra caution is probably warranted with this combination. 

Verapamil, diltiazem, amiodarone Diminished renal and nonrenal excretion ... 

Abciximab, aminophylline, amiodarone, amrinone, aspirin, carbamazepine, chlorpromazine, danazol, diltiazem, eptifi-batide, heparin, histamine2-receptor antagonists, low molecular weight heparins, methyldopa, milrinone, procainamide, quinidine, quinine, NSAIDs, thiazide diuretics, ticlopidine, tirofiban, and valproic acid... 

Numerous drugs ((1-blockers, diltiazem, verapamil, digoxin, and amiodarone) can cause bradyarrhythmias (sinus bradycardia and AV nodal blockade). 

Adenosine 3-Blockers Amiodarone Carbamazepine Chloroquine Digoxin Diltiazem Gatifloxacin... 

Ventricular Rate Control is achieved by inhibiting the proportion of electrical impulses conducted from the atria to the ventricles through the AV node. Therefore, drugs that are effective for ventricular rate control are those that inhibit AV nodal impulse conduction P-blockers, diltiazem, verapamil, and digoxin (Tables 6-5 and 6-6). Amiodarone also inhibits AV nodal conduction, but is not a preferred drug for ventricular rate control in AF due to its unfavorable adverse-effect profile (Table 6-6). 

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 enzyme is the principal participant in N-demethylation reactions where the substrate is a tertiary amine. The list of substrates includes erythromycin, ethylmor-phine, lidocaine, diltiazem, tamoxifen, toremifene, verapamil, cocaine, amiodarone, alfentanil and terfenadine. Carbon atoms in the allylic and benzylic positions, such as those present in quinidine, steroids and cyclosporin A, are also particularly prone to oxidation by CYP3A4, a range of substrates is illustrated in Figure 7.10. 

Drugs that may affect HMG-CoA reductase inhibitors include alcohol, amiodarone, antacids, azole antifungals, bile acid sequestrants, cimetidine, cyclosporine, diltiazem, erythromycin, gemfibrozil, isradipine, nefazodone, niacin, nicotinic acid, omeprazole, phenytoin, propranolol, protease inhibitors, ranitidine, rifampin, St. John s wort, and verapamil. 

Imipramine (Tofranil) [Antidepressant/TCA] WARNING Close observation for suicidal thinking or unusual changes in behavior Uses Depres-sion, enuresis, panic attack, chronic pain Action TCA t CNS synaptic serotonin or norepinephrine Dose Adults. Hospitalized Initial 100 mg/24 h PO in doses T over several wk 300 mg/d max Output Maint 50-150 mg PO hs, 300 mg/24 h max Peds. Antidepressant 1.5-5 mg/kg/24 h daUy-qid Enuresis >6 y 10-25 mg PO qhs T by 10-25 mg at 1-2-wk int vals (max 50 mg for 6-12 y, 75 mg for >12 y) Rx for 2-3 mo, then tap Caution [D, /-] Contra Use w/ MAOIs, NAG, acute recovery from MI, PRG, CHF, angina, CVD, arrhythmias Disp Tabs, caps SE CV Sxs, dizziness, xerostomia, discolored urine Interactions t Effects W/ amiodarone, anticholinergics, BBs, cimetidine, diltiazem, Li, OCPs, quinidine, phenothiazines, ritonavir, verapamil, EtOH, evening primrose oil t effects OF CNS depressants, hypoglycemics, warfarin T risk of serotonin synd W/MAOIs 4-... 

CYP3A4 HIV antivirals (e.g.. Ritonavir), amiodarone, cimetidine, diltiazem, erythromycin", grapefruit juice, ketoconazole... 

Inhibitors of the CYP3A4 isoenzyme could increase systemic dofetilide exposure. Inhibitors of this isoenzyme (e.g., macrolide antibiotics, azole antifungal agents, protease inhibitors, serotonin reuptake inhibitors, amiodarone, cannabinoids, diltiazem, grapefruit juice, nefazadone, norfloxacin, quinine, and zafirlukast) should be cautiously coadministered with TIKOSYN, because they can potentially increase dofetilide levels... 

Drugs that may inhibit cytochrome P450 metabolism of other drugs include amiodarone, androgens, atazanavir, chloramphenicol, cimetidine, ciprofloxacin, clarithromycin, cyclosporine, delavirdine, diltiazem, diphenhydramine, disulfiram, enoxacin, erythromycin, fluconazole, fluoxetine, fluvoxamine, furanocoumarins (substances in grapefruit juice), indinavir, isoniazid, itraconazole, ketoconazole, metronidazole, mexile-tine, miconazole, nefazodone, omeprazole, paroxetine, propoxyphene, quinidine, ritonavir, sulfamethizole, verapamil, voriconazole, zafirlukast, and zileuton. 

A4 Acetaminophen, alfentanil, amiodarone, astemizole, cocaine, cortisol, cyclosporine, dapsone, diazepam, dihydroergotamine, dihydropyridines, diltiazem, ethinyl estradiol, gestodene, indinavir, lidocaine, lovastatin, macrolides, methadone, miconazole, midazolam, mifepristone (RU 486), paclitaxel, progesterone, quinidine, rapamycin, ritonavir, saquinavir, spironolactone, sulfamethoxazole, sufentanil, tacrolimus, tamoxifen, terfenadine, testosterone, tetrahydro-cannabinol, triazolam, troleandomycin, verapamil Barbiturates, carbamazepine, macrolides, glucocorticoids, pioglitazone, phenytoin, rifampin Erythromycin, 613-hydroxy cortisol... 

CYP3A4 Inhibition Amiodarone, clarithromycin, erythromycin, cimetidine, cyclosporine, fluoxetine fluvoxamine, itraconazole, ketoconazole, nefazodone, verapamil, diltiazem HIV antivirals delaviridine, indanavire, nelfmavire, ritonavire, sequinavire Atorvastatin Lovastatin Simvastatin ... 

AMIODARONE CALCIUM CHANNEL BLOCKERS Risk of bradycardia, AV block and 1 BP when amiodarone coadministered with diltiazem or verapamil Additive negative inotropic and chronotropic effect. Also, amiodarone inhibits intestinal P-gp, which t the bioavailability of diltiazem and verapamil Monitor PR, BP and ECG closely watch for heart failure... 

PORFIMER I. ACE INHIBITORS -enalapril 2. ANALGESICS -celecoxib, ibuprofen, ketoprofen, naproxen 3. ANTIARRHYTHMICS — amiodarone 4. ANTIBIOTICS -ciprofloxacin, dapsone, sulphonamides, tetracyclines 5. ANTICANCER AND IMMUNOMODULATING DRUGS -fluorouracil (topical and oral) 6. ANTIDIABETIC DRUGS-glipizide 7. ANTIMALARIALS -hydroxychloroquine, quinine 8. ANTIPSYCHOTICS -chlorpromazine, fluphenazine 9. CALCIUM CHANNEL BLOCKERS - diltiazem 10. DIURETICS -bumetanide, furosemide, hydrochlorothiazide II. PARA-AMINOBENZOIC ACID (TOPICAL) 12. RETINOIDS-acitretin, isotretinoin 13. SALICYLATES (TOPICAL) t risk of photosensitivity reactions Attributed to additive effects Avoid exposure of skin and eyes to direct sunlight for 30 days after porfimer therapy... 

A 71-year-old woman, who had taken amiodarone 200 mg/day for 3 months and diltiazem for 8 months, developed extensive erythema, blistering, and erosions affecting 50% of the body surface area, with a maculo-papular rash on the limbs (205). She developed bilateral pneumonia and septicemia and died after 7 days. 

Sinus arrest with hypotension has been reported in a patient with a congestive cardiomyopathy when diltiazem was added to amiodarone (255). 

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