Quinidine with quinolones

Antacids also have clinically significant drug interactions with tetracycline, ferrous sulfate, isoniazid, quinidine, sul-fonylureas, and quinolone antibiotics. Antacid-drug interactions are influenced by antacid composition, dose, dosage schedule, and formulation. 

Like other aluminium salts, pulmonary aspiration of sucralfate can lead to acute lung injury. There is some systemic absorption of aluminium, which is probably significant only in patients with renal impairment. Administration can be associated with a degree of hypophosphataemia, and there is also interference with absorption of some other drugs, e.g. quinolone antibacterials, digoxin, quinidine, and warfarin. 

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. 

Clinically important, potentially hazardous interactions with abarelix, acenocoumarol, amisulpride, amprenavir, anisindione, anticoagulants, arsenic, astemizole, carbimazole, celiprolol, ciprofloxacin, dabigatran, degarelix, dicumarol, digoxin, diltiazem, enoxacin, fentanyl, fosamprenavir, gatifloxacin, grapefruit juice, lomefloxacin, methotrexate, moxifloxacin, nilotinib, norfloxacin, ofloxacin, oxprenolol, quinidine, quinolones, rifabutin, rifampin, rifapentine, ritonavir, simvastatin, sparfloxacin, sulpiride, tacrolimus, tipranavir, verapamil, warfarin, zuclopenthixol... 

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). 

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... 

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