Hypomagnesemia arrhythmia

All antiarrhythmic dra are used cautiously in patients with renal or hepatic disease. When renal or hepatic dysfunction is present, a dosage reduction may be necessary. All patients should be observed for renal and hepatic dysfunction. Quinidine and procainamide are used cautiously in patients with CHF. Disopyramide is used cautiously in patients with CHF, myasthenia gravis, or glaucoma, and in men with prostate enlargement. Bretylium is used cautiously in patients with digitalis toxicity because the initial release of norepinephrine with digitalis toxicity may exacerbate arrhythmias and symptoms of toxicity. Verapamil is used cautiously in patients with a history of serious ventricular arrhythmias or CHF. Electrolyte disturbances such as hypokalemia, hyperkalemia, or hypomagnesemia may alter the effects of the antiarrhythmic dru . Electrolytes are monitored frequently and imbalances corrected as soon as possible... 

Hypokalemia and hypomagnesemia may cause muscle fatigue or cramps. Serious cardiac arrhythmias may occur, especially in patients receiving digitalis therapy, patients with LV hypertrophy, and those with ischemic heart disease. Low-dose therapy (e.g., 25 mg hydrochlorothiazide or 12.5 mg chlorthalidone daily) rarely causes significant electrolyte disturbances. 

Significant systemic absorption by dermal or inhalation exposure may result in hypocalcemia and hypomagnesemia cardiac arrhythmias may result as a consequence/ ... 

The pulmonary toxicity of uranium compounds varies in animals. Reports of pulmonary toxicity in animals after acute-duration exposure to uranium are limited to experiments with uranium hexafluoride. Gasping and severe irritation to the nasal passages were reported after 10 minute exposures at 637 mg U/mg in rats and mice (Spiegl 1949) and nasal hemorrhage in rats after a 5 minute exposure to 54,503 mg/m (Leach et al. 1984). Uranium hexafluoride promptly hydrolyzes on contact with water to uranyl fluoride and hydrofluoric acid. Thus, the animals were potentially exposed to hydrofluoric acid, a potent toxicant to respiratory tract epithelium, which probably contributed to pulmonary tissue destruction (Leach et al. 1984 Spiegl 1949 Stokinger et al. 1953). In addition, exposure to fluoride ions can result in hypocalcemia, hypomagnesemia, pulmonary edema, metabolic acidosis, ventricular arrhythmia, and death (Meditext 1998). 

One of the more serious complications of magnesium deficiency is cardiac arrhythmias. Premature atrial complexes, atrial tachycardia and fibrillation, ventricular premature complexes, ventricular tachycardia, and ventricular fibrillation may be associated with magnesium deficiency. These effects maybe partly caused by the hypokalemia, renal wasting, and intracellular depletion of potassium caused by hypomagnesemia. 

Patients with persistent or recurrent VF or PVT following antiarrhythmic administration should be assessed for underlying electrolyte abnormalities as a cause for their refractory arrhythmia. The primary electrolyte abnormalities associated with refractory ventricular arrhythmias include hyperkalemia, hypokalemia, and hypomagnesemia. 

Hypokalemia and hypomagnesemia may cause muscle fatigue or cramps. However, serious cardiac arrhythmias can occur in patients with significant degrees of hypokalemia and hypomagnesemia. Patients at greatest risk are those with LVH, high coronary disease risk, previous myocardial infarction, a history of arrhythmia, or... 

Cardiovascular Cardiac arrhythmias (ventricular fibrillation, torsades de pointes, ordigoxin-induced arrhythmias), sudden cardiac death, and hypertension may be present. ECG abnormalities include widened QRS complex and peaked T waves with mild hypomagnesemia and prolonged PR interval, progressive widening of QRS complex, and flattened T waves with moderate to severe hypomagnesemia. 

Parenteral used for seizure prevention and control in severe preeclampsia or eclampsia without deleterious CNS depression in the mother, fetus, or newborn as replacement therapy in magnesium deficiency, especially in acute hypomagnesemia accompanied by signs of tetany similar to those observed in hypocalcemia to correct or prevent hypomagnesemia by addition to total parenteral nutrition admixture hypertension, encephalopathy, and convulsions in children with acute nephritis inhibition of premature labor as treatment of life-threatening ventricular arrhythmias for prevention and treatment of nutritional magnesium deficiency and as a laxative. 

Telithromycin may cause clinically significant QTc prolongation and increased risk of ventricular arrhythmia in predisposed patients. It should not be used in patients with prolonged QT syndrome, uncorrected hypokalemia or hypomagnesemia, profound bradycardia, or in patients receiving certain antiarrhythmics (e.g., quinidine, procainamide, amiodarone) or other agents that prolong QTc (e.g., cisapride, pimozide). 

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