Amiodarone Quinolones

Some quinolones can prolong the QT interval, and would be expected to increase the risk of torsade de pointes arrhythmias when used with quinidine. Of the quinolones used clinically, gatifloxacin, moxifloxacin, and sparfloxacin are known to prolong the QT interval (see Table 9.2 , (p.257)). There is also evidence that levofloxacin may prolong the QT interval (see Amiodarone + Quinolones , p.249). These quinolones should... 

Several drug classes, including tetracycline, sulfonamide, and quinolone antibiotics, as well as chlorothiazide, chlorpromazine, and amiodarone hydrochloride, have been shown to be photoantigens. Photosensitivity may persist even after withdrawal of the drug, as has been observed with the antiarrhythmic drug amiodarone hydrochloride, since it is lipophilic and can be stored for extended periods in the body fat (Unkovic et al., 1984). In addition, it is quite common for cross-reactions to occur between structurally related drugs of the same class. 

Hypersensitivity to fluoroquinolones or the quinolone group tendinitis or tendon rupture associated with quinolone use patients receiving disopyramide and amiodarone or other QTc-prolonging antiarrhythmic drugs reported to cause torsade... 

Phenytoin (Dilantin) [Anticenvulsant/Hydantoin] Uses Sz disorders Action X Sz spread in the motor cortex Dose Load Adults Peds. 15-20 mg/kg IV, 25 mg/min max or PO in 400-mg doses at 4-h intervals Maint Adults. Initial, 200 mg PO or IV bid or 300 mg hs then follow levels Peds. 4-7 mg/kg/24h PO or IV -s- daily-bid avoid PO susp (erratic absorption) Caution [D, +] Contra Heart block, sinus bradycardia Disp Caps, susp, inj SE Nystag-mus/ataxia early signs of tox gum hyperplasia w/ long-term use. IV BP, bradycardia, arrhythmias, phlebitis peripheral neuropathy, rash, blood dyscrasias, Stevens-Johnson synd Notes Levels Trough Just before next dose Therapeutic Peak 10-20 mcg/mL Toxic >20 mcg/mL phenytoin albumin bound, levels = bound free phenytoin w/ i albumin azotemia, low levels may be therapeutic (nl free levels) Interactions T Effects W/ amiodarone, allopurinol, chloramphenicol, disulfiram, INH, omeprazole, sulfonamides, quinolones, trimethoprim t... 

As with some other quinolones, moxifloxadn also prolongs the QTC interval [265], although the prolongation time of 4—6 ms (i.e., 1.4—1.6% of the starting interval) is relatively minimal. For safety reasons, the treatment of patients with QT interval prolongation and certain cardiac diseases is therefore contraindicated. Other medicaments with a potential for prolonging the QT interval may not be administered simultaneously with moxifloxacin. These indude anti-arrhythmic drugs of class IA (e.g., quinidine, hydroquinidine, disopyramide) and III (e.g., amiodarone, sotalol, dofetilide, ibutilide), intravenous erythromydn, tricyclic anti-depressives, and cisapride etc. 

VENLAFAXINE 1. ANTIARRHYTHMICS - amiodarone, disopyramide, procainamide, propafenone 2. ANTIBIOTICS — macrolides (especially azithromycin, clarithromycin, parenteral erythromycin, telithromycin), quinolones (especially moxifloxacin), quinupristin/ dalfopristin 3. ANTICANCER AND IMMUNOMODULATING DRUGS -arsenic trioxide 4. ANTIDEPRESSANTS-TCAs 5. ANTIEMETICS-dolasetron 6. ANTIFUNGALS-fluconazole, posaconazole, voriconazole 7. ANTIHISTAMINES-terfenadine, hydroxyzine, mizolastine 8. ANTIMALARIALS -artemetherwith lumefantrine, chloro-quine, hydroxychloroquine, mefloquine, quinine 9. ANTIPROTOZOALS -pentamidine isetionate 10. ANTIPSY-CHOTICS - atypicals, phenothiazines, pimozide 11. BETA-BLOCKERS -sotalol 12. BRONCHODILATORS-parenteral bronchodilators 13. CNS STIMULANTS - atomoxetine Risk of ventricular arrhythmias, particularly torsades de pointes Additive effect these drugs cause prolongation of the Q-T interval Avoid co-administration... 

It was necessary to use a film thickness of 200 pm for the total photo protection of multivitamin infusions containing ascorbic acid, thiamine hydrochloride, nicotin-amid, and pyridoxine hydrochloride. For amiodarone hydrochloride and a special quinolone infusion, which showed sensitivity to all wavelengths in the UV region up to 400 nm, the photo protection was considerably lower. However, a reduction of drug losses from 59% and 75% to 5% and 7% was still attainable using this cover thickness. It was concluded, that the limit of application for these particular UV protective covers is photolability of drug solutions with activation spectra above 385 tun. 

Clinically important, potentially hazardous interactions with abacavir, amiodarone, bretylium, chlorpromazine, ciprofloxacin, disopyramide, enoxacin, fluphenazine, gatifloxacin, lomefloxacin, mesoridazine, moxifloxacin, norfloxacin, ofloxacin, phenothiazines, procainamide, prochlorperazine, promethazine, quinidine, quinolones, sotalol, sparfloxacin, thioridazine, trifluoperazine... 

Leukopenia, eosinophilia, and mild elevations in serum transaminases occur rarely. Prolongation of the QT interval has been observed with sparfloxacin and to a lesser extent with gati-floxacin and moxifloxacin. Quinolones probably should be used only with caution in patients who are taking certain antiarrhythmics, including amiodarone, quinidine, and procainamide (see Chapter 34). 

ANTIARRHYTHMICS - amiodarone, disopyramide, procainamide, propafenone 2. ANTIBIOTICS-macrolides (especially azithromycin, clarithromycin, parenteral erythromycin, telithromycin), quinolones (especially moxifloxacin), quinupristin/dalfbpristin... 

I. ANTI ARRHYTHMICS - amiodarone, disopyramide, procainamide, propafenone 2. ANTIBIOTICS -macrolides (especially azithromycin, clarithromycin, parenteral erythromycin, telithromycin), quinolones (especially moxifloxacin), quinupristin/ dalfbpristin 3. ANTICANCER AND IMMUNOMODULATING DRUGS-arsenic trioxide 4. ANTIDEPRESSANTS-TCAs, venlafaxine 5. ANTIEMETICS -dolasetron 5. ANTIFUNGALS - fluconazole, posaconazole, voriconazole... 

In general the concurrent use of two or more drugs that prolong the QT interval should be avoided, because this increases the risk of torsade de pointes arrhythmias (see also Drugs that prolong the QT interval + Other drugs that prolong the QT interval , p.257). The above quinolones should probably be avoided in patients on amiodarone. Ciprofloxacin appears to have less effect on the QT interval. ... 

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