Fibrillation intravenous drug dose

Quinine is a cinchona alkaloid that acts rapidly against all four species of Plasmodium. It is used to treat protozoal infections and leg cramps, and as a bitter and flavoring agent. However, the drug is not used prophylactically for malaria. Quinines are contraindicated in patients with a history of hypersensitivity to quinine or quinidine. They should not be used in the presence of hemolysis and should be used with caution in patients with atrial fibrillation, cardiac conduction defects, or heart block. Quinine administration in myasthenia gravis may aggravate the disease, hence it should be avoided. Quinine can be used in pregnancy.37 Intravenous infusion of quinine should be slow, and the patient should be monitored for cardiotoxicity.38 Cinchonism, which is characterized by tinnitus, GI disturbances, and impaired vision may occur with therapeutic doses of quinine.39... 

When the limits of tolerance are approached, there may be palpitation, extra beats, and a rise in blood pressure. In sensitive individuals or at high doses, ventricular fibrillation, subarachnoid hemorrhage, and even hemiplegia have been known to occur. Adrenahne can occasionally cause pulmonary edema (4,5). It is possible that in at least some of these cases the drug has been inadvertently injected intravenously. 

Erythromycin has antidysrhythmic properties similar to those of Class lA antidysrhythmic drugs, and causes an increase in atrial and ventricular refractory periods. This is only likely to be a problem in patients with heart disease or in those who are receiving drugs that delay ventricular repolarization (5). High-doses intravenously have caused ventricular fibrillation and torsade de pointes (6). Each episode of dysrhythmia, QT interval prolongation, and myocardial dysfunction occurred 1-1.5 hours after erythromycin infusion and resolved after withdrawal. 

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