Amiodarone ventricular arrhythmias caused

Amiodarone is useful in the treatment of supraventricular and ventricular arrhythmias. Amiodarone tends to hove a number of side-effects, such os photosensitivity. Patients ore advised to ovoid exposure to sunlight and apply a sun protection factor on a doily basis. Amiodarone may also cause reversible corneal microdeposits os a result of v/hich patients find night glare irritating and so patients ore advised to ovoid driving at night. 

VENLAFAXINE 1. ANTIARRHYTHMICS - amiodarone, disopyramide, procainamide, propafenone 2. ANTIBIOTICS — macrolides (especially azithromycin, clarithromycin, parenteral erythromycin, telithromycin), quinolones (especially moxifloxacin), quinupristin/ dalfopristin 3. ANTICANCER AND IMMUNOMODULATING DRUGS -arsenic trioxide 4. ANTIDEPRESSANTS-TCAs 5. ANTIEMETICS-dolasetron 6. ANTIFUNGALS-fluconazole, posaconazole, voriconazole 7. ANTIHISTAMINES-terfenadine, hydroxyzine, mizolastine 8. ANTIMALARIALS -artemetherwith lumefantrine, chloro-quine, hydroxychloroquine, mefloquine, quinine 9. ANTIPROTOZOALS -pentamidine isetionate 10. ANTIPSY-CHOTICS - atypicals, phenothiazines, pimozide 11. BETA-BLOCKERS -sotalol 12. BRONCHODILATORS-parenteral bronchodilators 13. CNS STIMULANTS - atomoxetine Risk of ventricular arrhythmias, particularly torsades de pointes Additive effect these drugs cause prolongation of the Q-T interval Avoid co-administration... 

B Because this patient has asthma and is wheezing, calcium channel blockers are the drug class of choice. Unlike beta-blockers and adenosine, they do not cause bronchospasm. Beta-blockers and adenosine should be used cautiously in patients with obstructive lung disease, and use should be avoided in patients with asthma. Digoxin is not contraindicated, but it is not the drug of choice due to its slow onset. Amiodarone is indicated for ventricular arrhythmias, but not PSVT. 

Answer E. Increased sympathetic activity is a major problem in hyperthyroidism and is best managed by use of beta blockers, which can offset cardiac stimulatory effects. Propranolol has an ancillary action in thyrotoxicosis in that it prevents conversion of T4 to T3 via its inhibition of 5 deiodinase. Amiodarone causes difficult-to-predict adverse effects on thyroid function and would not be appropriate in a patient with hyperthyroidism. Bretylium is an IV agent reserved for ventricular arrhythmias. Digoxin is not ideal because of its complex actions on the heart, which include both inhibition and stimulation. 

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). 

With chronic use, amiodarone may cause ventricular arrhythmias (mono-morphic or polymorphic ventricular tachycardia see p 14) or bradyanhyth-mias (sinus arrest, AV block). Amiodarone may cause pneumonitis or pulmonary fibrosis, hepatitis, photosensitivity dermatitis, comeal deposits, hypothyroidism or hyperthyroidism, tremor, ataxia, and peripheral neuropathy. 

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