Quinidine Side Effects

Please note - some side effects for Quinidine may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).

Side Effects of Quinidine - for the consumer

Quinidine Sulfate

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Quinidine Sulfate:

Blurred vision; diarrhea; heartburn; nausea; stomach discomfort; vomiting.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); dark urine; dizziness or lightheadedness; fainting; fast, slow, or irregular heartbeat; headache; hearing changes or loss of hearing; mood or mental changes; pale stools; ringing in ears; severe or persistent stomach pain; vision changes; yellowing of the skin or eyes.

Quinidine Gluconate Controlled-Release Tablets

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Quinidine Gluconate Controlled-Release Tablets:

Blurred vision; diarrhea; heartburn; nausea; stomach discomfort; vomiting.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); dark urine; deafness; dizziness; fainting; fast or slow heartbeat; headache; hearing loss; irregular heartbeat; lightheadedness; liver toxicity; pale stools; psychotic reactions; ringing in ears; yellowing of the skin or eyes.

Quinidine Sulfate Controlled-Release Tablets

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Quinidine Sulfate Controlled-Release Tablets:

Blurred vision; diarrhea; heartburn; nausea; stomach discomfort; vomiting.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); dark urine; dizziness or lightheadedness; fainting; fast, slow, or irregular heartbeat; headache; hearing changes or loss of hearing; mood or mental changes; pale stools; ringing in ears; severe or persistent stomach pain; vision changes; yellowing of the skin or eyes.

For the professional

Quinidine

Quinidine preparations have been used for many years, but there are only sparse data from which to estimate the incidence of various adverse reactions. The adverse reactions most frequently reported have consistently been gastrointestinal, including diarrhea, nausea, vomiting, and heart–burn/esophagitis. In one study of 245 adult outpatients who received Quinidine to suppress premature ventricular contractions, the incidences of reported adverse experiences were as shown in the table below. The most serious Quinidine–associated adverse reactions are described above under Warnings.

Intramuscular injections of Quinidine gluconate are typically followed by moderate to severe local pain. Some patients will develop tender nodules at the site of injection that persist for several weeks.

Vomiting and diarrhea can occur as isolated reactions to therapeutic levels of Quinidine, but they may also be the first signs of cinchonism, a syndrome that may also include tinnitus, reversible high–frequency hearing loss, deafness, vertigo, blurred vision, diplopia, photophobia, headache, confusion, and delirium. Cinchonism is most often a sign of chronic Quinidine toxicity, but it may appear in sensitive patients after a single moderate dose.

A few cases of hepatotoxicity, including granulomatous hepatitis, have been reported in patients receiving Quinidine. All of these have appeared during the first few weeks of therapy, and most (not all) have remitted once Quinidine was withdrawn.

Autoimmune and inflammatory syndromes associated with Quinidine therapy have included fever, urticaria, flushing, exfoliative rash, bronchospasm, pneumonitis, psoriasiform rash, pruritus and lymphadenopathy, hemolytic anemia, vasculitis, thrombocytopenic purpura, uveitis, angioedema, agranulocytosis, the sicca syndrome, arthralgia, myalgia, elevation in serum levels of skeletal–muscle enzymes, and a disorder resembling systemic lupus erythematosus.

Convulsions, apprehension, and ataxia have been reported, but it was not clear that these were not simply the results of hypotension and consequent cerebral hypoperfusion. There are many reports of syncope. Acute psychotic reactions have been reported to follow the first dose of Quinidine, but these reactions appear to be extremely rare.

Other adverse reactions occasionally reported include depression, mydriasis, disturbed color perception, night blindness, scotomata, optic neuritis, visual field loss, photo–sensitivity, and abnormalities of pigmentation.

Quinidine Extended Release Tablets

Quinidine preparations have been used for many years, but there are only sparse data from which to estimate the incidence of various adverse reactions. The adverse reactions most frequently reported have consistently been gastrointestinal, including diarrhea, nausea, vomiting, and heartburn/esophagitis.

In the reported study that was closest in character to the predominant approved use of Quinidine gluconate, 86 adult outpatients with atrial fibrillation were followed for six months while they received slow-release Quinidine bisulfate tablets, 600 mg (approximately 400 mg of Quinidine base) twice daily. The incidences of adverse experiences reported more than once were as shown in the table below. The most serious Quinidine-associated adverse reactions are described above under WARNINGS.

Vomiting and diarrhea can occur as isolated reactions to therapeutic levels of Quinidine, but they may also be the first signs of cinchonism, a syndrome that may also include tinnitus, reversible high-frequency hearing loss, deafness, vertigo, blurred vision, diplopia, photophobia, headache, confusion, and delirium. Cinchonism is most often a sign of chronic Quinidine toxicity, but it may appear in sensitive patients after a single moderate dose.

A few cases of hepatotoxicity, including granulomatous hepatitis, have been reported in patients receiving Quinidine. All of these have appeared during the first few weeks of therapy, and most (not all) have remitted once Quinidine was withdrawn.

Autoimmune and inflammatory syndromes associated with Quinidine therapy have included fever, urticaria, flushing, exfoliative rash, bronchospasm, psoriasiform rash, pruritus and lymphadenopathy, hemolytic anemia, vasculitis, thrombocytopenic purpura, uveitis, angioedema, agranulocytosis, the sicca syndrome, arthralgia, myalgia, elevation in serum levels of skeletal-muscle enzymes, a disorder resembling systemic lupus erythematosus, and pneumonitis.

Convulsions, apprehension, and ataxia have been reported, but it is not clear that these were not simply the results of hypotension and consequent cerebral hypoperfusion. There are many reports of syncope. Acute psychotic reactions have been reported to follow the first dose of Quinidine, but these reactions appear to be extremely rare.

Other adverse reactions occasionally reported include depression, mydriasis, disturbed color perception, night blindness, scotomata, optic neuritis, visual field loss, photosensitivity, and abnormalities of pigmentation.

Quinidine Tablets

Quinidine preparations have been used for many years, but there are only sparse data from which to estimate the incidence of various adverse reactions. The adverse reactions most frequently reported have consistently been gastrointestinal, including diarrhea, nausea, vomiting, and heartburn/esophagitis. In one study of 245 adult outpatients who received Quinidine to suppress premature ventricular contractions, the incidences of reported adverse experiences were as shown in the table below. The most serious Quinidine-associated adverse reactions are described above under WARNINGS.

Vomiting and diarrhea can occur as isolated reactions to therapeutic levels of Quinidine, but they also may be the first signs of cinchonism, a syndrome that also may include tinnitus, reversible high-frequency hearing loss, deafness, vertigo, blurred vision, diplopia, photophobia, headache, confusion, and delirium. Cinchonism is most often a sign of chronic Quinidine toxicity, but it may appear in sensitive patients after a single moderate dose.

A few cases of hepatotoxicity, including granulomatous hepatitis, have been reported in patients receiving Quinidine. All of these have appeared during the first few weeks of therapy, and most (not all) have remitted once Quinidine was withdrawn.

Autoimmune and inflammatory syndromes associated with Quinidine therapy have included pneumonitis, fever, urticaria, flushing, exfoliative rash, bronchospasm, psoriasiform rash, pruritus and lymphadenopathy, hemolytic anemia, vasculitis, thrombocytopenic purpura, uveitis, angioedema, agranulocytosis, the sicca syndrome, arthralgia, myalgia, elevation in serum levels of skeletal-muscle enzymes, and a disorder resembling systemic lupus erythematosus.

Convulsions, apprehension, and ataxia have been reported, but it is not clear that these were not simply the results of hypotension and consequent cerebral hypoperfusion. There are many reports of syncope.

Acute psychotic reactions have been reported to follow the first dose of Quinidine, but these reactions appear to be extremely rare.

Other adverse reactions occasionally reported include depression, mydriasis, disturbed color perception, night blindness, scotomata, optic neuritis, visual field loss, photosensitivity, and abnormalities of pigmentation.

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