Cardioquin: Full Drug Profile

Cardioquin - General Information

An optical isomer of quinine, extracted from the bark of the Cinchona tree and similar plant species. This alkaloid dampens the excitability of cardiac and skeletal muscles by blocking sodium and potassium currents across cellular membranes. It prolongs cellular action potential, and decreases automaticity. Cardioquin also blocks muscarinic and alpha-adrenergic neurotransmission.

Pharmacology of Cardioquin

Cardioquin, a hydantoin anticonvulsant, is used alone or with phenobarbital or other anticonvulsants to manage tonic-clonic seizures, psychomotor seizures, neuropathic pain syndromes including diabetic neuropathy, digitalis-induced cardiac arrhythmias, and cardiac arrhythmias associated with QT-interval prolongation.

Cardioquin for patients

Before prescribing QUINAGLUTE® as prophylaxis against recurrence of atrial fibrillation, the physician should inform the patient of the risks and benefits to be expected. Discussion should include the facts

• that the goal of therapy will be a reduction (probably not to zero) in the frequency of episodes of atrial fibrillation; and
• that reduced frequency of fibrillatory episodes may be expected, if achieved, to bring symptomatic benefit; but
• that no data are available to show that reduced frequency of fibrillatory episodes will reduce the risks of irreversible harm through stroke or death; and in fact
• that such data as are available suggest that treatment with QUINAGLUTE® is likely to increase the patient's risk of death.

To confirm whether this is the most current prescribing information available on Quinaglute®, or to obtain the most current prescribing information, please call Berlex Laboratories at 1-888-BERLEX-4 (choose option #4, Product Usage Information).

Cardioquin Interactions

Altered pharmacokinetics of quinidine: diltiazem significantly decreases the clearance and increases the t_1/2 of quinidine, but quinidine does not alter the kinetics of diltiazem. Drugs that alkalinize the urine (carbonic-anhydrase inhibitors, sodium bicarbonate, thiazide diuretics) reduce renal elimination of quinidine.
By pharmacokinetic mechanisms that are not well understood, quinidine levels are increased by coadministration of amiodarone or cimetidine. Very rarely, and again by mechanisms not understood, quinidine levels are decreased by coadministration of nifedipine.
Hepatic elimination of quinidine may be accelerated by coadministration of drugs (phenobarbital, phenytoin, rifampin) that induce production of cytochrome P450IIIA4.
Perhaps because of competition for the P450IIIA4 metabolic pathway, quinidine levels rise when ketaconazole is coadministered.
Coadministration of propranolol usually does not affect quinidine pharmacokinetics, but in some studies the b-blocker appeared to cause increases in the peak serum levels of quinidine, decreases in quinidine's volume of distribution, and decreases in total quinidine clearance. The effects (if any) of coadministration of other b-blockers on quinidine pharmacokinetics have not been adequately studied.
Hepatic clearance of quinidine is significantly reduced during coadministration of verapamil, with corresponding increases in serum levels and half-life.
Altered pharmacokinetics of other drugs: Quinidine slows the elimination of digoxin and simultaneously reduces digoxin's apparent volume of distribution. As a result, serum digoxin levels may be as much as doubled. When quinidine and digoxin are coadministered, digoxin doses usually need to be reduced. Serum levels of digitoxin are also raised when quinidine is coadministered, although the effect appears to be smaller.
By a mechanism that is not understood, quinidine potentiates the anticoagulatory action of warfarin, and the anticoagulant dosage may need to be reduced.
Cytochrome P450IID6 is an enzyme critical to the metabolism of many drugs, notably including mexiletine, some phenothiazines, and most polycyclic antidepressants. Constitutional deficiency of cytochrome P450IID6 is found in less than 1% of Orientals, in about 2% of American blacks, and in about 8% of American whites. Testing with debrisoquine is sometimes used to distinguish the P450IID6-deficient "poor metabolizers" from the majority-phenotype "extensive metabolizers".
When drugs whose metabolism is P450IID6-dependent are given to p.o. metabolizers, the serum levels achieved are higher, sometimes much higher, than the serum levels achieved when identical doses are given to extensive metabolizers. To obtain similar clinical benefit without toxicity, doses given to poor metabolizers may need to be greatly reduced. In the case of prodrugs whose actions are actually mediated by P450IID6-produced metabolites (for example, codeine and hydrocodone, whose analgesic and antitussive effects appear to be mediated by morphine and hydromorphone, respectively), it may not be possible to achieve the desired clinical benefits in poor metabolizers.
Quinidine is not metabolized by cytochrome P450IID6, but therapeutic serum levels of quinidine inhibit the action of cytochrome P450IID6, effectively converting extensive metabolizers into p.o. metabolizers. Caution must be exercised whenever quinidine is prescribed together with drugs metabolized by cytochrome P450IID6.
Perhaps by competing for pathways of renal clearance, coadministration of quinidine causes an increase in serum levels of procainamide.
Serum levels of haloperidol are increased when quinidine is coadministered.
Presumably because both drugs are metabolized by cytochrome P450IIIA4, coadministration of quinidine causes variable slowing of the metabolism of nifedipine. Interactions with other dihydropyridine calcium channel blockers have not been reported, but these agents (including felodipine, nicardipine, and nimodipine) are all dependent upon P450IIIA4 for metabolism, so similar interactions with quinidine should be anticipated.
Altered pharmacodynamics of other drugs: Quinidine's anticholinergic, vasodilating, and negative inotropic actions may be additive to those of other drugs with these effects, and antagonistic to those of drugs with cholinergic, vasoconstricting, and positive inotropic effects. For example, when quinidine and verapamil are coadministered in doses that are each well tolerated as monotherapy, hypotension attributable to additive peripheral a-blockade is sometimes reported.
Quinidine potentiates the actions of depolarizing (succinylcholine, decamethonium) and nondepolarizing (d-tubocurarine, pancuronium) neuromuscular blocking agents. These phenomena are not well understood, but they are observed in animal models as well as in humans. In addition, in vitro addition of quinidine to the serum of pregnant women reduces the activity of pseudocholinesterase, an enzyme that is essential to the metabolism of succinylcholine.
Non-interactions of quinidine with other drugs: Quinidine has no clinically significant effect on the pharmacokinetics of diltiazem, flecainide, mephenytoin, metoprolol, propafenone, propranolol, quinine, timolol, or tocainide.

Conversely, the pharmacokinetics of quinidine are not significantly affected by caffeine, ciprofloxacin, digoxin, diltiazem, felodipine, omeprazole, or quinine. Quinidine's pharmacokinetics are also unaffected by cigarette smoking.

Cardioquin Contraindications

Quinidine is contraindicated in patients who are known to be allergic to it, or who have developed thrombocytopenic purpura during prior therapy with quinidine or quinine.
In the absence of a functioning artificial pacemaker, quinidine is also contraindicated in any patient whose cardiac rhythm is dependent upon a junctional or idioventricular pacemaker, including patients in complete atrioventricular block.
Quinidine is also contraindicated in patients who, like those with myasthenia gravis, might be adversely affected by an anticholinergic agent.

Additional information about Cardioquin

Cardioquin Indication: For the treatment of ventricular pre-excitation and cardiac dysrhythmias Mechanism Of Action: Cardioquin acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. The antiarrhythmic actions are mediated through effects on sodium channels in Purkinje fibers. Drug Interactions: Amiloride Amiloride decreases the antiarrhythmic effect of quinidine Amiodarone Amiodarone increases the effect of quinidine Amitriptyline Cardioquin increases the effect of the tricyclic agent Clomipramine Cardioquin increases the effect of the tricyclic agent Nortriptyline Cardioquin increases the effect of the tricyclic agent Desipramine Cardioquin increases the effect of the tricyclic agent Doxepin Cardioquin increases the effect of the tricyclic agent Imipramine Cardioquin increases the effect of the tricyclic agent Protriptyline Cardioquin increases the effect of the tricyclic agent Trimipramine Cardioquin increases the effect of the tricyclic agent Amobarbital The anticonvulsant decreases the effect of quinidine Aprobarbital The anticonvulsant decreases the effect of quinidine Butabarbital The anticonvulsant decreases the effect of quinidine Butalbital The anticonvulsant decreases the effect of quinidine Butethal The anticonvulsant decreases the effect of quinidine Dihydroquinidine barbiturate The anticonvulsant decreases the effect of quinidine Fosphenytoin The anticonvulsant decreases the effect of quinidine Heptabarbital The anticonvulsant decreases the effect of quinidine Hexobarbital The anticonvulsant decreases the effect of quinidine Methohexital The anticonvulsant decreases the effect of quinidine Methylphenobarbital The anticonvulsant decreases the effect of quinidine Pentobarbital The anticonvulsant decreases the effect of quinidine Phenobarbital The anticonvulsant decreases the effect of quinidine Phenytoin The anticonvulsant decreases the effect of quinidine Primidone The anticonvulsant decreases the effect of quinidine Cardioquin barbiturate The anticonvulsant decreases the effect of quinidine Secobarbital The anticonvulsant decreases the effect of quinidine Talbutal The anticonvulsant decreases the effect of quinidine Anisindione Quinine/quinidine increases the anticoagulant effect Dicumarol Quinine/quinidine increases the anticoagulant effect Digoxin Quinine/quinidine increases the effect of digoxin Digitoxin Quinine/quinidine increases the effect of digoxin Acenocoumarol Quinine/quinidine increases the anticoagulant effect Warfarin Quinine/quinidine increases the anticoagulant effect Aripiprazole Cardioquin increases the effect and toxicity of aripiprazole Atomoxetine The CYP2D6 inhibitor could increase the effect and toxicity of atomoxetine Cimetidine Cimetidine increases the effect of quinidine Codeine Cardioquin decreases the analgesic effect of codeine Dextromethorphan Cardioquin increases the toxicity of dextromethorphan Diltiazem Diltiazem increases the effect and toxicity of quinidine Nelfinavir Nelfinavir increases the effect and toxicity of quinidine Nifedipine Decreased quinidine effect, increased nifedipine effect Posaconazole Contraindicated co-administration Procainamide Cardioquin increases the effect of procainamide Propafenone Cardioquin increases the effect of propafenone Quinupristin This combination presents an increased risk of toxicity Rifampin Rifampin decreases the effect of quinidine Ritonavir Ritonavir increases the effect and toxicity of quinidine Verapamil Verapamil increases the effect of quinidine Atazanavir Increased risk of cardiotoxicity/arrhythmias Cisapride Increased risk of cardiotoxicity and arrhythmias Clarithromycin Increased risk of cardiotoxicity and arrhythmias Erythromycin Increased risk of cardiotoxicity and arrhythmias Gatifloxacin Increased risk of cardiotoxicity and arrhythmias Grepafloxacin Increased risk of cardiotoxicity and arrhythmias Levofloxacin Increased risk of cardiotoxicity and arrhythmias Mesoridazine Increased risk of cardiotoxicity and arrhythmias Moxifloxacin Increased risk of cardiotoxicity and arrhythmias Thioridazine Increased risk of cardiotoxicity and arrhythmias Ofloxacin Increased risk of cardiotoxicity and arrhythmias Ranolazine Possible additive effect on QT prolongation Sparfloxacin Increased risk of cardiotoxicity and arrhythmias Telithromycin Increased risk of cardiotoxicity and arrhythmias Terfenadine Increased risk of cardiotoxicity and arrhythmias Voriconazole Increased risk of cardiotoxicity and arrhythmias Ziprasidone Increased risk of cardiotoxicity and arrhythmias Rivastigmine Possible antagonism of action Donepezil Possible antagonism of action Galantamine Possible antagonism of action Atracurium The quinine derivative increases the effect of the muscle relaxant Gallamine Triethiodide The quinine derivative increases the effect of the muscle relaxant Metocurine The quinine derivative increases the effect of the muscle relaxant Pancuronium The quinine derivative increases the effect of the muscle relaxant Succinylcholine The quinine derivative increases the effect of the muscle relaxant Vecuronium The quinine derivative increases the effect of the muscle relaxant Itraconazole The imidazole increases the effect and toxicity of quinidine Ketoconazole The imidazole increases the effect and toxicity of quinidine Magnesium The antacid increases the effect of quinidine Salicylate-magnesium The antacid increases the effect of quinidine Sodium bicarbonate The antacid increases the effect of quinidine Food Interactions: Not Available Generic Name: Quinidine Synonyms: Quinidine Sulfate; Quinidine Gluconate Drug Category: Antiarrhythmic Agents Drug Type: Small Molecule; Approved Other Brand Names containing Quinidine: Apo-Quinidine; Biquin Durules; Cardioquin; Chinidin; Cin-Quin; Coccinine; Conchinin; Conchinine; Conquinine; Duraquin; Kinidin; Novoquinidin; Pitayin; Pitayine; Quin-Release; Quinact; Quinaglute; Quinaglute Dura-Tabs; Quinalan; Quinate; Quinatime; Quindine; Quinicardine; Quinidex; Quinidex Extentabs; Quinora; Absorption: Not Available Toxicity (Overdose): Not Available Protein Binding: 80-88% Biotransformation: Not Available Half Life: 6-8 hours Dosage Forms of Cardioquin: Tablet, extended release Oral Tablet Oral Solution Intramuscular Chemical IUPAC Name: (S)-[(4S,5R,7R)-5-ethenyl-1-azabicyclo[2.2.2]octan-7-yl]-(6-methoxyquinolin-4-yl)methanol Chemical Formula: C20H24N2O2 Quinidine on Wikipedia: https://en.wikipedia.org/wiki/Quinidine Organisms Affected: Humans and other mammals