Quinidex Extentabs Side Effects
Generic Name: quinidine
Note: This page contains side effects data for the generic drug quinidine. It is possible that some of the dosage forms included below may not apply to the brand name Quinidex Extentabs.
For the Consumer
Applies to quinidine: capsule, solution, tablet, tablet extended release
As well as its needed effects, quinidine (the active ingredient contained in Quinidex Extentabs) may cause unwanted side effects that require medical attention.
If any of the following side effects occur while taking quinidine, check with your doctor immediately:Less common
- Abdominal pain and/or yellow eyes or skin
- blurred and/or double vision, confusion, delirium, disturbed color perception, headache, noises or ringing in the ear, and/or visual intolerance of light
- dizziness or lightheadedness
- Chest pain, fever, general discomfort, joint pain, joint swelling, muscle pain, and/or skin rash
- nosebleeds or bleeding gums
- unusual tiredness or weakness and/or pale skin
Some quinidine side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:More common
- loss of appetite
- muscle weakness
- nausea or vomiting
For Healthcare Professionals
Applies to quinidine: compounding powder, injectable solution, oral tablet, oral tablet extended release
Cinchonism may be classified as mild, moderate, or severe depending on symptoms. Mild cinchonism includes symptoms of blurred vision, transient deafness, anorexia, nausea, weakness, vertigo, tinnitus, diarrhea, and headache. Mild cinchonism does not always occur with higher dosages, nor does it preclude further quinidine (the active ingredient contained in Quinidex Extentabs) therapy. Moderate cinchonism includes vomiting, hypotension, a 25% to 50% increase in QRS duration, and rare premature ventricular contractions. Severe cinchonism is characterized by myocardial toxicity such as malignant arrhythmias, QRS duration greater than 50%, high degree AV heart block, or cardiac arrest.[Ref]
Quinidine side effects have varied from vague neurological and gastrointestinal complaints to myocardial toxicity. The most frequently reported symptoms have been diarrhea, nausea, and vomiting. The risk of toxicity is greater when plasma quinidine concentrations exceed 4 mg/L.
Dose-related cinchonism may be the first sign of quinidine toxicity. Cinchonism refers to a syndrome caused by any of the cinchona alkaloids, including quinidine. It most often is a sign of chronic toxicity, but may occur after a single moderate dose in sensitive patients.[Ref]
Cardiovascular side effects have included hypotension, syncope, increased QRS duration (500 to 600 msec), and myocardial toxicity. Tachyarrhythmia has occurred in approximately 2% of patients. Quinidine-induced long QT syndrome has resulted in rare cases of torsades de pointes.
Myocardial toxicity may present as malignant arrhythmias, increased QRS duration of greater than 50%, high degree AV heart block, or cardiac arrest. Quinidine (the active ingredient contained in Quinidex Extentabs) may significantly decrease stroke volume and cardiac output.
Routine use following myocardial infarction is not recommended in view of the Cardiac Arrhythmia Suppression Trial (CAST) data.[Ref]
The use of quinidine to prevent atrial fibrillation in patients with chronic atrial fibrillation is somewhat controversial. A large, randomized, controlled study comparing quinidine to placebo has shown no difference in efficacy and no demonstrable reduction in overall mortality in treated patients. The crude mortality rate was greater in patients treated with quinidine relative to patients treated with placebo.[Ref]
Gastrointestinal side effects have been the most frequently reported adverse effects. Anorexia, nausea, vomiting, and diarrhea occurred in up to 30% of patients. Quinidine pill esophagitis has been reported. Nausea, vomiting, and diarrhea may be part of the cinchonism syndrome resulting from dose-related quinidine (the active ingredient contained in Quinidex Extentabs) toxicity.[Ref]
A 76-year-old man developed progressive dysphagia to solids during quinidine therapy. Upper endoscopy revealed a proximal narrowing, but no findings of cancer or infection. Quinidine pill esophagitis was suspected and the drug was discontinued. The lesion resolved one month later and did not recur.[Ref]
Nervous system side effects have included dizziness, headache, tremor, nervousness and coordination difficulties. Such symptoms may be part of the cinchonism syndrome and signs of quinidine (the active ingredient contained in Quinidex Extentabs) toxicity. The anticholinergic activity of quinidine may exacerbate myasthenia gravis. Convulsions have been reported, but the association with quinidine has not been clearly defined.[Ref]
An 85-year-old man with atrial flutter developed drowsiness, emesis, and icterus associated with elevated liver function tests and marked centrilobular cholestasis with mild bile duct inflammation per liver biopsy within ten days after beginning quinidine (the active ingredient contained in Quinidex Extentabs) therapy. There was no evidence of biliary obstruction per ultrasound. The signs and symptoms of hepatitis resolved after discontinuation of quinidine.
A 58-year-old man with paroxysmal atrial fibrillation developed fever, lethargy, nausea, and abdominal pain associated with elevated liver function tests and no serological evidence of a viral etiology within ten days after beginning quinidine therapy. No liver biopsy was performed. The signs and symptoms of hepatitis began to resolve within three days after discontinuation of quinidine.
Rare cases of reversible granulomatous hepatitis, presenting as fever, urticarial rash, elevated liver function tests, and mild thrombocytopenia have been associated with quinidine. In a long-term study of 15 patients with a history of quinidine-associated hepatitis, no persistent liver function abnormalities were observed.[Ref]
Hepatic toxicity associated with quinidine is believed primarily due to hypersensitivity to quinidine. Hypersensitivity-induced hepatitis has occurred in approximately 2% of patients, usually within the first two weeks of therapy. Jaundice occurred rarely. Resolution was complete in most cases within 4 to 8 weeks following discontinuation. Not all cases have resolved. Granulomatous hepatitis has been reported.[Ref]
Ocular side effects have included mydriasis, color perception changes, night blindness, scotomata, optic neuritis, and visual field loss. Blurred vision, diplopia, and photophobia may be part of the dose-related cinchonism syndrome. Quinidine (the active ingredient contained in Quinidex Extentabs) keratopathy, an extremely rare ocular side effect, has been reported.[Ref]
A 66-year-old man with coronary artery disease developed photophobia and blurred vision while taking quinidine, metoprolol, furosemide, isosorbide, and digoxin. Slit-lamp examination revealed superficial granular deposits within the corneal epithelium; the epithelial surface was smooth and did not contain fluorescein upon staining. The corneal deposits disappeared within two months after discontinuing quinidine.[Ref]
Hematologic abnormalities including leukopenia, thrombocytopenia, and rare cases of leukocytosis have occurred.[Ref]
Cases of an IgG antibody requiring the presence of quinidine, with activity against leukocytes and platelets have been reported. In some cases, significant infection or hemorrhage resulted.
A 60-year-old man developed malaise, weakness, chills, and oral ulcerations within three days of beginning quinidine and digoxin for atrial fibrillation. Laboratory examination revealed a profoundly low leukocyte count and bone marrow aspiration revealed a hypocellular myeloid line. The neutrophil count returned to baseline within three days after discontinuation of quinidine and continuation of digoxin. The authors found eight other such cases in a review of medical literature.[Ref]
A 52-year-old man developed malaise, an extensive maculopapular rash, palpable purpura, mental status changes, rigors, nausea, and night sweats during therapy with quinidine (the active ingredient contained in Quinidex Extentabs) and digoxin. Laboratory findings included proteinuria, elevated liver function tests, eosinophilia, an elevated antinuclear antibody titer, and renal biopsy findings consistent with allergic granulomatous angiitis. The syndrome worsened following quinidine discontinuation, but resolved gradually with steroid therapy. Because allergic reactions to digoxin are rare, the authors implicated quinidine. Rechallenge was not performed.
A 54-year-old man with a history of atrial fibrillation, treated with digoxin and quinidine sulfate, developed fever and malaise associated with nodular infiltrates on chest X-ray. His condition worsened despite treatment with an oral cephalosporin. A diagnostic evaluation ruled out heart failure; tests for typical and atypical infections were negative. Pulmonary function testing revealed mild restriction. Two days after stopping quinidine the signs and symptoms of pneumonitis resolved. Bronchoalveolar lavage and transbronchial biopsy revealed changes consistent with allergic pneumonitis. Rechallenge with quinidine resulted in recurrent signs and symptoms of allergic pneumonitis.[Ref]
Hypersensitivity-induced hepatitis has occurred in approximately 2% of patients, usually within the first two weeks of therapy. Hypersensitivity reactions including of uveitis, allergic vasculitis, lymphadenopathy, hemolytic anemia, thrombocytopenia, agranulocytosis, bronchospasm, pneumonitis and photosensitive dermatitis psoriaform rash, angioedema, sicca syndrome, arthralgia, myalgia, and elevated levels of skeletal muscle enzymes have been reported.[Ref]
Dermatologic side effects including photosensitive rashes, psoriasis, abnormal pigmentation, and actinic dermatitis have been reported. Quinidine (the active ingredient contained in Quinidex Extentabs) has been identified as a possible cause of lichen planus in susceptible patients.[Ref]
A 57-year-old man with premature ventricular depolarizations developed a papular rash on his back and chest. Resolution was complete within four weeks of discontinuation of therapy. The patient was on no other oral medications.
An 83-year-old man developed a bluish-grey discoloration involving his skin, oral mucosa, and nailbeds which resolved over four months following discontinuation of quinidine. Other medications were continued.
A 64-year-old man with a history of convalescent psoriasis vulgaris experienced an exacerbation of psoriasis within 72 hours after initiating quinidine therapy. The psoriasis was refractory to aggressive PUVA therapy and resolved only when quinidine was discontinued.[Ref]
Approximately 30 cases of quinidine-induced systemic lupus erythematosus have been reported. The majority of patients were Caucasian and elderly, without gender difference. The most frequent complaint was polyarthralgias (87%).[Ref]
Immunologic side effects including systemic lupus erythematosus have been rarely associated with quinidine therapy. Rare cases of quinidine-induced polyarthropathy without development of antinuclear antibodies have been reported.[Ref]
Renal side effects have been limited to rare reports of quinidine-induced nephrotic syndromes.[Ref]
A 64-year-old woman developed edema, proteinuria (3 grams per 24 hours), hypercholesterolemia, elevated complement levels, and elevated antinuclear antibody titers within three months after beginning digoxin and quinidine. Signs of the nephrotic syndrome resolved within seven days after discontinuation of quinidine, but continuation of digoxin. Rechallenge with quinidine resulted in fatigue, myalgias, arthralgias, anorexia, and weakness. The author believed this case represented quinidine-induced nephrotic syndrome or a quinidine-induced lupus erythematosus-like illness complicated by renal disease.
A 63-year-old man receiving allopurinol for gout developed progressive uremia, proteinuria, edema, and purpura after beginning quinidine therapy. The patient required hemodialysis secondary to biopsy-proven, rapidly progressive glomerulonephritis. A macrophage migration-inhibition test was negative in the presence of both quinidine and allopurinol. Such tests may be falsely negative in the presence of uremia. The authors believed quinidine caused Henoch-Schonlein purpura in this patient based on a chronologic association and lack of allopurinol-associated problems following chronic therapy.[Ref]
A 73-year-old man with supraventricular tachycardia developed visual hallucinations, delusions, and psychomotor agitation within 90 minutes of the initial dose of quinidine (the active ingredient contained in Quinidex Extentabs) A serum quinidine level at the time was 0.8 mg/L (therapeutic 3 to 6 mg/L). The patient's mental status returned to baseline after discontinuation of quinidine.
A 67-year-old man with a supraventricular arrhythmia and hypertension developed psychosis and psychomotor hyperactivity within two hours after starting quinidine. A serum quinidine level at the time was 1 mg/L (therapeutic 3 to 6 mg/L). The patient's mental status returned to baseline after discontinuation of quinidine.[Ref]
Psychiatric side effects of depression have been associated with quinidine. Rare cases of acute psychosis and psychomotor agitation have been reported with subtherapeutic quinidine levels in elderly patients.[Ref]
Musculoskeletal effects including a case of profound musculoskeletal weakness has been reported.[Ref]
A 68-year-old woman with paroxysmal atrial fibrillation developed progressive proximal limb muscle weakness within two weeks after starting quinidine. Symptoms resolved upon discontinuation of therapy. Rechallenge was associated with recurrent weakness and a diffuse, pruritic rash. A diagnostic evaluation failed to reveal evidence of myasthenia gravis.[Ref]
1. "Product Information. Quinidex (quinidine)." Wyeth-Ayerst Laboratories, Philadelphia, PA.
2. "Multum Information Services, Inc. Expert Review Panel"
3. Kirch W, Halabi A, Hinrichsen H "Hemodynamic effects of quinidine and famotidine in patients with congestive heart failure." Clin Pharmacol Ther 51 (1992): 325-33
4. Dhein S, Schott M, Gottwald E, Klaus W "Electrocardiological profile and proarrhythmic effects of quinidine, verapamil and their combination: a mapping study." Naunyn Schmiedebergs Arch Pharmacol 352 (1995): 94-101
5. Koenig W, Schinz AM "Spontaneous ventricular flutter and fibrillation during quinidine medication." Am Heart J 105 (1983): 863-5
6. Bauman JL, Bauernfeind RA, Hoff JV, et al "Torsade de pointes due to quinidine: observations in 31 patients." Am Heart J 107 (1984): 425-30
7. Reimold SC, Chalmers TC, Berlin JA, Antman EM "Assessment of the efficacy and safety of antiarrhythmic therapy for chronic atrial fibrillation: observations on the role of trial design and implications of drug-related mortality." Am Heart J 124 (1992): 924-32
8. Oberg KC, Otoole MF, Gallastegui JL, Bauman JL "''late'' proarrhythmia due to quinidine." Am J Cardiol 74 (1994): 192-4
9. Swiryn S, Kim SS "Quinidine-induced syncope." Arch Intern Med 143 (1983): 314-6
10. Bhavnani SM, Preston SL "Monitoring of intravenous quinidine infusion in the treatment of plasmodium falciparum malaria." Ann Pharmacother 29 (1995): 33-5
11. Sokolow M, Perloff DB "The clinical pharmacology and use of quinidine in heart disease." Prog Cardiovasc Dis 3 (1961): 316-30
12. Conn HL, Luchi RJ "Some quantitative aspects of the binding of quinidine and related quinoline compounds by human serum albumin." J Clin Invest 40 (1961): 509-16
13. Kessler KM, Leech RC, Spann JF "Blood collection techniques, heparin and quinidine protein binding." Clin Pharmacol Ther 25 (1979): 204-10
14. Morganroth J, Horowitz LN "Incidence of proarrhythmic effects from quinidine in the outpatient treatment of benign or potentially lethal ventricular arrhythmias." Am J Cardiol 56 (1985): 585-7
15. Woo E, Greenblatt DJ "A reevaluation of intravenous quinidine." Am Heart J 96 (1978): 829-32
16. Wasty N, Saksena S, Barr MJ "Comparative efficacy and safety of oral cibenzoline and quinidine in ventricular arrhythmias: a randomized crossover study." Am Heart J 110 (1985): 1181-8
17. Hohnloser SH, Vandeloo A, Baedeker F "Efficacy and proarrhythmic hazards of pharmacologic cardioversion of atrial fibrillation: prospective comparison of sotalol versus quinidine." J Am Coll Cardiol 26 (1995): 852-8
18. Raehl CL, Patel AK, LeRoy M "Drug-induced torsade de pointes." Clin Pharm 4 (1985): 675-90
19. Au PK, Bhandari AK, Bream R, et al "Proarrhythmic effects of antiarrhythmic drugs during programmed ventricular stimulation in patients without ventricular tachycardia." J Am Coll Cardiol 9 (1987): 389-97
20. Swerdlow CD, Yu JO, Jacobson E, et al "Safety and efficacy of intravenous quinidine." Am J Med 75 (1983): 36-42
21. Herman JE, Bassan HM "Liver injury due to quinidine." JAMA 234 (1975): 310-11
22. Chajek T, Lehrer B, Geltner D, Levij IS "Quinidine-induced granulomatous hepatitis." Ann Intern Med 81 (1974): 774-6
23. Romankiewicz JA, Reidenberg M, Drayer D, Franklin JE "The noninterference of aluminum hydroxide gel with quinidine sulfate absorption: An approach to control quinidine-induced diarrhea." Am Heart J 96 (1978): 518-20
24. Handler SD, Hirsch NR, Haas K, Davidson FZ "Quinidine hepatitis." Arch Intern Med 135 (1975): 871-2
25. Zahger D, Gilon D, Gotsman MS "Delayed quinidine-induced diarrhea after five years of treatment ." Chest 101 (1992): 296
26. Deisseroth A, Morganroth J, Winokur S "Quinidine-induced liver disease." Ann Intern Med 77 (1972): 595-7
27. Wong RK, Kikendall JW, Dachman AH "Quinaglute-induced esophagitis mimicking an esophageal mass." Ann Intern Med 105 (1986): 62-3
28. Fisher CM "Visual disturbances associated with quinidine and quinine." Neurology 31 (1981): 1569-71
29. Stoffer SS, Chandler JH "Quinidine-induced exacerbation of myasthenia gravis in patient with Graves' disease ." Arch Intern Med 140 (1980): 283-4
30. Hogan DB, Morin J, Crilly RG "Unusual hepatotoxic reaction to quinidine ." Can Med Assoc J 130 (1984): 973
31. Slezak P "Quinidine hepatotoxicity ." Med J Aust 1 (1981): 139
32. Caraco Y, Arnon R, Raveh D "Quinidine-induced uveitis." Isr J Med Sci 28 (1992): 741-3
33. Zaidman GW "Quinidine keratopathy." Am J Ophthalmol 97 (1984): 247-9
34. LeBlanc KE "A second case of quinidine-induced thrombocytopenia with pulmonary hemorrhage ." Arch Intern Med 140 (1980): 1250-1
35. Danielson DA, Douglas SW 3d, Herzog P, et al "Drug-induced blood disorders." JAMA 252 (1984): 3257-60
36. Sureda A, Hernandez Madrid A, Perez Vaquero MA, et al "Quinidine-induced agranulocytosis of abrupt onset." Acta Haematol 84 (1990): 43-4
37. Garty M, Ilfeld D, Kelton JG "Correlation of a quinidine-induced platelet-specific antibody with development of thrombocytopenia." Am J Med 79 (1985): 253-5
38. Castro O, Nash I "Quinidine leukopenia and thrombocytopenia with a drug-dependent leukoagglutinin." N Engl J Med 296 (1977): 572
39. Cines DB, Laposata M, Schaefer PW, Margolin DH "A 70-year-old woman with atrial fibrillation and the rapid onset of hemorrhagic manifestations - quinidine-induced thrombocytopenia. cerebral hemorrhage." N Engl J Med 332 (1995): 1363-70
40. Nieminen U, Kekomaki R "Quinidine-induced thrombocytopenic purpura: clinical presentation in relation to drug-dependent and drug-independent platelet antibodies." Br J Haematol 80 (1992): 77-82
41. Vincent PC "In vitro study of drug-induced granulocytopenia ." N Engl J Med 302 (1980): 1151
42. Salom IL "Purpura due to inhaled quinidine ." JAMA 266 (1991): 1220
43. Bedell SE, Kang JL "Leukocytosis and left shift associated with quinidine fever." Am J Med 77 (1984): 345-6
44. Chong BH, Berndt MC, Koutts J, Castaldi PA "Quinidine-induced thrombocytopenia and leukopenia: demonstration and characterization of distinct antiplatelet and antileukocyte antibodies." Blood 62 (1983): 1218-23
45. Eisner EV, Carr RM, MacKinney AA "Quinidine-induced agranulocytosis." JAMA 238 (1977): 884-6
46. Ascensao JL, Flynn PJ, Slungaard A, et al "Quinidine-induced neutropenia: report of a case with drug-dependent inhibition of granulocyte colony generation." Acta Haematol 72 (1984): 349-54
47. Lipsker D, Walther S, Schulz R, Nave S, Cribier B "Life threatening vasculitis related to quinidine occurring in a healthy volunteer during a clinical trial." Eur J Clin Pharmacol 54 (1998): 815
48. Quin J, Adamski M, Howlin K, et al "Quinidine-induced allergic granulomatous angiitis: an unusual cause of acute renal failure." Med J Aust 148 (1988): 145-6
49. Poukkula A, Paakko P "Quinidine-induced reversible pneumonitis." Chest 106 (1994): 304-6
50. Shalit M, Flugelman MY, Harats N, et al "Quinidine-induced vasculitis." Arch Intern Med 145 (1985): 2051-2
51. Hustead JD "Granulomatous uveitis and quinidine hypersensitivity ." Am J Ophthalmol 112 (1991): 461-2
52. Knobler H, Levij IS, Gavish D, Chajek-Shaul T "Quinidine-induced hepatitis: a common and reversible hypersensitivity reaction." Arch Intern Med 146 (1986): 526-8
53. Naschitz JE, Yeshurun D "Quinidine induced sicca syndrome." J Toxicol Clin Toxicol 20 (1983): 367-71
54. Bramlet DA, Posalaky Z, Olson R "Granulomatous hepatitis as a manifestation of quinidine hypersensitivity." Arch Intern Med 140 (1980): 395-7
55. Aviram A "Henoch-Schonlein syndrome associated with quinidine ." JAMA 243 (1980): 432-3
56. Marx JL, Eisenstat BA, Gladstein AH "Quinidine photosensitivity." Arch Dermatol 119 (1983): 39-43
57. Burkhart CG "Quinidine-induced acne ." Arch Dermatol 117 (1981): 603-4
58. Katta R "Lichen planus." Am Fam Physician 61 (2000): 3319-24, 3327-8
59. Manzi S, Kraus VB, St Clair EW "An unusual photoactivated skin eruption: quinidine-induced livedo reticularis." Arch Dermatol 125 (1989): 417-8
60. Harwell WB "Quinidine-induced psoriasis ." J Am Acad Dermatol 9 (1983): 278
61. Lim HW, Buchness MR, Ashinoff R, Soter NA "Chronic actinic dermatitis: study of the spectrum of chronic photosensitivity in 12 patients." Arch Dermatol 126 (1990): 317-23
62. Mahler R, Sissons W, Watters K "Pigmentation induced by quinidine therapy." Arch Dermatol 122 (1986): 1062-4
63. Brenner S, Cabili S, Wolf R "Widespread erythematous scaly plaques in an adult. Psoriasiform eruption induced by quinidine." Arch Dermatol 129 (1993): 1331-2,
64. Birek C, Main JH "Two cases of oral pigmentation associated with quinidine therapy." Oral Surg Oral Med Oral Pathol 66 (1988): 59-61
65. West SG, McMahon M, Portanova JP "Quinidine-induced lupus erythematosus." Ann Intern Med 100 (1984): 840-2
66. Lau CP, Wong KL, Wong CK, Leung WH "Acute lymphadenopathy complicating quinidine therapy." Postgrad Med J 66 (1990): 406-7
67. Kendall MJ, Hawkins CF "Quinidine-induced systemic lupus erythematosus." Postgrad Med J 46 (1970): 729-31
68. Alloway JA, Salata MP "Quinidine-induced rheumatic syndromes." Semin Arthritis Rheum 24 (1995): 315-22
69. Sukenik S, Horowitz J, Katz A, et al "Quinidine-induced lupus erythematosus-like syndrome: three case reports and a review of the literature." Isr J Med Sci 23 (1987): 1232-4
70. Amadio P Jr, Cummings DM, Dashow L "Procainamide, quinidine, and lupus erythematosus ." Ann Intern Med 102 (1985): 419
71. Gay RG, Fielder KL, Grogan TM "Quinidine-induced reactive lymphadenopathy." Am J Med 82 (1987): 143-5
72. Bar-El Y, Shimoni Z, Flatau E "Quinidine-induced lupus erythematosus." Am Heart J 111 (1986): 1209-10
73. Cohen MG, Kevat S, Prowse MV, Ahern MJ "Two distinct quinidine-induced rheumatic syndromes." Ann Intern Med 108 (1988): 369-71
74. Anderson FP, Wanerka GR "Drug induced systemic lupus erythematosus due to quinidine." Conn Med 36 (1972): 84-5
75. Chisholm JC, Jr "Quinidine-induced nephrotic syndrome." J Natl Med Assoc 77 (1985): 920-2
76. Billig N, Buongiorno P "Quinidine-induced organic mental disorders." J Am Geriatr Soc 33 (1985): 504-6
77. Deleu D, Schmedding E "Acute psychosis as idiosyncratic reaction to quinidine: report of two cases." Br Med J 294 (1987): 1001-2
78. Hall CD, Malouf N "Skeletal muscle weakness resulting from quinidine ingestion." South Med J 80 (1987): 403-4
It is possible that some side effects of Quinidex Extentabs may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.
More about Quinidex Extentabs (quinidine)
Related treatment guides
Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.