Functional class
Func. class.: Antidysrhythmic (Class IA)
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Drug reference
Func. class.: Antidysrhythmic (Class IA)
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Chem. class.: QuiNINE dextroisomer
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Do not confuse: quiNIDine/quiNINE
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ACTION: Prolongs duration of action potential and effective refractory period, thus decreasing myocardial excitability; anticholinergic properties Q
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USES: Atrial fibrillation, PAT, ventricu- lar tachycardia, atrial flutter, Wolff- Parkinson-White syndrome; PVST
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CONTRAINDICATIONS: Hyper- sensitivity, idiosyncratic response, digoxin toxicity, blood dyscrasias, myasthenia gravis, AV block Precautions: Pregnancy, breastfeeding, children, geriatric patients, electrolyte imbalance, renal/hepatic disease, HF, respiratory depression, bradycardia, hypo- tension, syncope
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Black Box Warning: Cardiac arrhyth- mias, MI Black Box Warning: Cardiac toxicity: asystole, ventricular dysrhythmias, wid- ening QRS, torsades de pointes • CNS effects: dizziness, confusion, psy- chosis, paresthesias, seizures; product should be discontinued • Hepatotoxicity: monitor LFTs for first 1-2 mo of treatment • Pregnancy/breastfeeding: use only if clearly needed; avoid use in breastfeed- ing, excreted in breast milk
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SIDE EFFECTS CV: Hypotension, bradycardia, PVCs, heart block, CV collapse, arrest, torsades de pointes, widening QRS complex, ven- tricular tachycardia EENT: Cinchonism: tinnitus, blurred vision, hearing loss, mydriasis, disturbed color vision GI: Nausea, vomiting, anorexia, abdomi- nal pain, diarrhea, hepatotoxicity HEMA: Thrombocytopenia, hemolytic anemia, agranulocytosis, hypoprothrom- binemia INTEG: Rash, urticaria, angioedema, swelling, photosensitivity, flushing with severe pruritus RESP: Dyspnea, respiratory depression
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INTERACTIONS • Additive vagolytic effect: anticholiner- gic blockers Increase: cardiac depression: other anti- dysrhythmics, phenothiazines, reserpine Increase: effects of neuromuscular block- ers, digoxin, warfarin, tricyclics, pro pranolol Increase: QT prolongation—macrolides, quinolones, tricyclics, procainamide, anti- psychotics Increase: quiNIDine effects—cimetidine, sodium bicarbonate, carbonic anhydrase inhibitors, antacids, hydroxide suspen- sions, amiodarone, verapamil, NIFEdi pine, protease inhibitors Decrease: quiNIDine effects—barbitu- rates, phenytoin, rifampin, sucralfate, cholinergics Drug/Herb Increase: quiNIDine effect—hawthorn, licorice Drug/Food • Delayed absorption, decreased metab- olism: grapefruit juice, avoid use Drug/Lab Test Decrease: platelets, HB, granulocytes
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DOSAGE AND ROUTES QuiNIDine gluconate • Adult: PO (ext rel) 324-648 mg q8- 12hr; IM 600 mg, then 400 mg q2hr; IV give 16 mg/min QuiNIDine sulfate PVST/WPW/atrial fibrillation/flutter • Adult: PO 200-300 mg q6-8hr × 5-8 doses; may increase daily until sinus rhythm restored; max 4 g/day given only after digitalization; maintenance 200-300 mg tid-qid or EXT REL 300-600 mg q8-12hr
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Available forms: Gluconate: ext rel tabs 324 mg; sulfate: tabs 200, 300 mg
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Administer: • AV node blocker (digoxin) before starting quinidine to avoid increased ven- tricular rate • Do not break, crush, chew ext rel products • With full glass of water or with food; GI upset occurs • Do not use with grapefruit juice
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Assess: • Blood levels (therapeutic level 2-5 mcg/mL), CBC, LFTs • For cinchonism: tinnitus, headache, nausea, dizziness, fever, vertigo, tremors; may lead to hearing loss
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Evaluate: • Therapeutic response: decreased dys- rhythmias
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CLINICAL CONSIDERATIONS
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Patient and caregiver information: • That if dizziness, drowsiness oc- curs, to avoid driving or hazardous activities • To use sunglasses; product may cause sensitivity to light • To carry emergency ID stating disease, medication use • How to take pulse; when to notify pre- scriber • To avoid all products unless approved by prescriber • Not to crush, chew ext rel product • Not to use grapefruit juice with this product • QuiNIDine toxicity (cinchonism): to report immediately visual changes, nau- sea, headache, ringing in the ears • To report diarrhea, anorexia, decreased B/P
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PHARMACOKINETICS PO: (sulfate) peak 1-6 hr, duration 6-8 hr, (sulfate ER) peak 4 hr, duration 8-12 hr; (gluconate PO) peak 3-4 hr, duration 6-8 hr, half-life 6-7 hr (prolonged in geriatric patients, cirrhosis, HF), metabolized in liver, excreted unchanged (10%-50%) by kidneys, protein bound (80%-90%)
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• Adult: PO (ext rel) 324-648 mg q8- 12hr; IM 600 mg, then 400 mg q2hr; IV give 16 mg/min QuiNIDine sulfate PVST/WPW/atrial fibrillation/flutter
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• Adult: PO 200-300 mg q6-8hr × 5-8 doses; may increase daily until sinus rhythm restored; max 4 g/day given only after digitalization; maintenance 200-300 mg tid-qid or EXT REL 300-600 mg q8-12hr
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