Lidocaine Disopyramide

Qd Disopyramide, lidocaine -chlorodiso-pyramide Determination in serum... 

Simultaneous disopyramide, lidocaine, metoprolol, nadolol, procainamide, quinidine, timolol, verapamil... 

In vitro studies found quinupristin/dalfopristin inhibited the cytochrome P450 isoenzyme CYP3A4-mediated metabolism of docetaxel, tamoxifen, and terfenadine. Quinupristin/dalfopristin is predicted to raise the levels of other drugs ineluding antiarrhythmics (disopyramide, lidocaine, quinidine), antiretrovirals (such as delavirdine, indinavir, nevirapine, ritonavir), astemizole, carbamazepine, cisapride, methyl-prednisolone, paclitaxel, statins (but see Lipid regulating drugs , (p.l086)), and vinca alkaloids. More study is needed. 

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... 

Drugs that may be affected by beta blockers include flecainide, gabapentin, haloperidol, hydralazine, phenothiazines, anticoagulants, benzodiazepines, clonidine, disopyramide, epinephrine, ergot alkaloids, lidocaine, nondepolarizing muscle relaxants, prazosin, sulfonylureas, and theophylline. 

Mechanism of action. Na -channel blocking antiarrhythmics resemble most local anesthetics in being cationic amphiphilic molecules (p.206 exception phenytoin, p.191). Possible molecular mechanisms of their inhibitory effects are outlined on p.202 in more detail. Their low structural specificity is reflected by a low selectivity toward different cation channels. Besides the Na channel. Carotid 1C channels are also likely to be blocked. Accordingly, cationic amphiphilic antiarrhythmics affect both the depolarization and repolarization phases. Depending on the substance, AP duration can be increased (Class IA), decreased (Class IB), or remain the same (Class IC). Antiarrhythmics representative of these categories include Class IA—quinidine, procainamide, ajmaline, disopyramide Class IB—lidocaine, mexile-tine, tocainide Class IC—flecainide, propafenone. 

Digoxin does not interact with a variety of antidysrhjdhmic drugs, including ajmaline, aprindine, lidocaine, lidoflazine (225), and moracizine (226). Other drugs that may have minor and clinically unimportant interactions include cap-topril, carvedilol, disopyramide, and flosequinan. 

A 65-year-old woman, who had had normal preoperative serum electrolytes and a normal QT interval with sinus rhythm, received hydroxyzine and atropine premedication followed by thiopental and vecuronium for anesthetic induction. Endotracheal intubation was difficult and precipitated atrial fibrillation, which was refractory to disopyramide 100 mg. Anesthesia was then maintained with sevoflurane 2% and nitrous oxide 50%. Ten minutes later ventricular tachycardia ensued, refractory to intravenous lidocaine, disopyramide, and magnesium. DC cardioversion resulted in a change to a supraventricular tachycardia, which then deteriorated to torsade de pointes. External cardiac massage and further DC cardioversion were initially unsuccessful, but the cardiac rhythm reverted to atrial fibrillation 10 minutes after the sevoflurane was switched off. Two weeks later she had her operation under combined epidural and general anesthesia, with no changes in cardiac rhythm. 

D Amiodarone is the best option. Disopyramide, quinidine, and sotalol all have negative inotropic effects, which may exacerbate his CHF. Lidocaine may be given in patients with CHF, but it is only administered IV due to its low bioavailability and is not suitable for long-term maintenance. 

Clinically important, potentially hazardous interactions with alcohol, amiodarone, beta-blockers, cimetidine, donidine, digoxin, diltiazem, disopyramide, ephedrine, epinephrine, ergot alkaloids, guanethidine, halothane, isoprenaline, lidocaine, noradrenaline, NSAIDs, phenylephrine, quinidine, reserpine, verapamil... 

A series of dibenzazepines (18a, 18b) were compared to disopyramide (.1) The compounds suppressed ventricular arrhythmias in dogs but may have been more toxic than the latter. Preliminary reports on a series of 3-amino-3-methyloxindoles indicate that one member (19) is as effective as lidocaine in the mouse chloroform test and possesses a higher LD50 59... 

Na+ Anticonvulsant drugs Class I antiarrhythmics Diuretic drugs Local anesthetic drugs Carbamazepine, phenytoin, valproic acid lA Disopyramide, procainamide, quinidine IB Lidocaine, mexiletine, phenytoin, tocainide IC Encainide, flecainide, propafenone Amiloride Bupivacaine, cocaine, lidocaine, mepivacaine, tetracaine... 

Moricizine (600 to 900 mg/day given every 8 hours in three equally divided doses) is indicated in the treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia, that are life threatening. Because of the proarrhythmic effects of moricizine, its use should be reserved for patients in whom the benefits of treatment outweigh the risks. Moricizine is a class 1C antiarrhythmic agent with potent local anesthetic activity and myocardial-membrane-stabilizing effects. It shares some of the characteristics of the class lA (disopyramide, procainamide, or quinidine), of class IB (lidocaine, mexiletene, phenytoin, or tocainide), or class 1C agents (encainide, flecainide, or propafenone) in that it reduces the fast inward current carried by sodium ions. Moricizine shortens phase 2 and 3... 

Another potential for drug interaction of roxithromycin may involve changes in binding of drugs to plasma proteins [26, 39]. In in vitro binding experiments, Zini et al. [26] found that disopyramide displaced roxithromycin and increased the free concentration of roxithromycin. The magnitude of the increase was not reported. Similar results were not seen with lidocaine or prednisolone [26]. Thus, the clinical significance of this interaction is unknown. 

Also analyzed acebutolol, acepromazine, acetaminophen, acetazolamide, acetophenazine, albuterol, amitriptyline, amobarbital, amoxapine, antipsrrine, atenolol, atropine, azata-dine, baclofen, benzocaine, bromocriptine, brompheniramine, brotizolam, bupivacaine, buspirone, butabarbital, butalbital, caffeine, carbamazepine, cetirizine, chlorqyclizine, chlordiazepoxide, chlormezanone, chloroquine, chlorpheniramine, chlorpromazine, chlorpropamide, chlorprothixene, chlorthalidone, chlorzoxazone, cimetidine, cisapride, clomipramine, clonazepam, clonidine, clozapine, cocaine, codeine, colchicine, qyclizine, (yclo-benzaprine, dantrolene, desipramine, diazepam, diclofenac, diflunisal, diltiazem, diphenhydramine, diphenidol, dipheno late, dipyridamole, disopyramide, dobutamine, doxapram, doxepin, droperidol, encainide, ethidium bromide, ethopropazine, fenoprofen, fentanyl, flavoxate, fluoxetine, fluphenazine, flurazepam, flurbiprofen, fluvoxamine, fii-rosemide, glutethimide, glyburide, guaifenesin, haloperidol, homatropine, hydralazine, hydrochlorothiazide, hydrocodone, hydromorphone, hydro g chloroquine, hydroxyzine, ibuprofen, imipramine, indomethacin, ketoconazole, ketoprofen, ketorolac, labetalol, le-vorphanol, lidocaine, loratadine, lorazepam, lovastatin, loxapine, mazindol, mefenamic acid, meperidine, mephenytoin, mepivacaine, mesoridazine, metaproterenol, methadone, methdilazine, methocarbamol, methotrexate, methotrimeprazine, methoxamine, methyl-dopa, methylphenidate, metoclopramide, metolazone, metoprolol, metronidazole, midazolam, moclobemide, morphine, nadolol, nalbuphine, naloxone, naphazoline, naproxen, nifedipine, nizatidine, norepinephrine, nortriptyline, oxazepam, oxycodone, oxymetazo-line, paroxetine, pemoline, pentazocine, pentobarbital, pentoxifylline, perphenazine, pheniramine, phenobarbital, phenol, phenolphthalein, phentolamine, phenylbutazone, phenyltoloxamine, phenytoin, pimozide, pindolol, piroxicam, pramoxine, prazepam, prazosin, probenecid, procainamide, procaine, prochlorperazine, procyclidine, promazine, promethazine, propafenone, propantheline, propiomazine, propofol, propranolol, protriptyline, quazepam, quinidine, quinine, racemethorphan, ranitidine, remoxipride, risperidone, salicylic acid, scopolamine, secobarbital, sertraline, sotalol, spironolactone, sulfinpyrazone, sulindac, temazepam, terbutaline, terfenadine, tetracaine, theophylline, thiethyl-perazine, thiopental, thioridazine, thiothixene, timolol, tocainide, tolbutamide, tolmetin, trazodone, triamterene, triazolam, trifluoperazine, triflupromazine, trimeprazine, trimethoprim, trimipramine, verapamil, warfarin, xylometazoline, yohimbine, zopiclone... 

Noninterfering acetaminophen, N-acetylprocainamide, amikacin, caffeine, carbamaze-pine, chloramphenicol, clonazepam, (yclosporine, diazepam, digoxin, disopyramide, etho-suximide, flurazepam, gentamicin, haloperidol, kanamycin, lidocaine, meprobamate. 

Harrison, P.M. Tonkin, A.M. McLean, A.J. Simple and rapid analysis of atenolol and metoprolol in plasma using solid-phase extraction and high-performance liquid chromatography. J.Chromatogr, 1985, 339, 429-433 [plasma SPE fluorescence detection LOD 10 ng/mL non-interfering chlorothiazide, disopyramide, furosemide, hydralazine, lidocaine, methydopa, prazosin, verapamil simultaneous alprenolol, oxprenolol, pindolol, practolol, propranolol, timolol]... 

---