Amiodarone side effects

Ventricular fibrillation should be terminated by electrical defibrillation. Alternatively, lidocaine can be injected intravenously. In cases with lower frequency, ventricular tachyarrhythmia class I diugs such as aj marine, flecainide or propafenone are more effective as a result of the use-dependence of lidocaine. For prophylaxis treatment, amiodarone or sotalol may be helpful or the implantation of a cardioverter-defibrillator system. Acute amiodarone (i.v. in higher doses) can also terminate ventricular tachyarrhythmias. This action, however, seems to be mediated by its INa-blocking side effects and not (or less) by its class III like effects. 

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. 

Q79 As opposed to flecainide, amiodarone is not associated with pneumonitis as a side-effect. Signs of pneumonitis include progressive shortness of breath or cough. 

Amiodarone is an anti-arrhythmic drug indicated in supraventricular and ventricular arrhythmias. One of the main side-effects is photosensitivity and patients are advised to avoid exposure to sunlight and use sun protection factors. 

Amiodarone (Figure 8.2) is an efficacious drug that causes a number of side-effects. The presence of iodine in the molecule is unusual and hypo- and hyperthyroidism have been reported in patients. Although the loss of iodine is relatively slow the relatively large daily dose size and long half-life of the drug and its de-ethylated metabolite suggest that the presence of iodine in the molecule is responsible for its toxicity [3]. 

Sotalol, as the racemate (a 1 1 mixture of the d- and 1-enantiomers), has a well-documented class Ill-antiarrhythmic activity, without showing the various side-effects of amiodarone. The -adrenoceptor blockade by this agent, however, limits its use in patients with heart failure. Dofetilide is an example of a newer, rather pure class in-antiarrhythmic, virtually devoid of other pharmacological properties. 

Amiodarone is regarded as one of the most efficacious antiarrhythmic agents because of its usefulness in the management of a variety of cardiac rhythm disorders with minimal tendency for induction of torsades de pointes tachyarrhythmia. Its use, however, is limited by the multiple and severe noncardiac side effects that it produces. 

Amiodarone may elicit life-threatening side effects in addition to presenting substantial management difh-culties associated with its use. The oral formulation of amiodarone is indicated only for the treatment of life-threatening recurrent ventricular arrhythmias (e.g., recurrent ventricular hbrillation and/or recurrent hemo-dynamicaUy unstable ventricular tachycardia) that have not responded to other potentially effective antiarrhythmic drugs or when alternative interventions could not be tolerated. Despite its efficacy as an antiarrhythmic agent, there is no evidence from clinical trials that the use of amiodarone favorably affects survival. 

Nelfinavir (Viracept) is probably the most commonly used protease inhibitor because of its low incidence of serious adverse effects. Its most common side effects are diarrhea and flatulence these may resolve with continued use. In addition to the drugs contraindicated for use with all protease inhibitors, amiodarone, rifampin, and quinidine are contraindicated in patients taking nelfinavir. 

Geriatric Considerations - Summary Eszopiclone is the only hypnotic which has been shown to maintain efficacy over long-term use (6 months) and may have a role in the management of chronic sleep problems in olderadults. Because eszopiclone is a substrate of CYP C3A, and 2E1, it should be used with caution, especially with drugs such as nefazodone, clarithromycin, and amiodarone. This agent has been newly approved for use in the US and has not been well studied in terms of falls or other geriatric side effects. 

Chronic oral therapy with amiodarone is associated with several side effects, including pulmonary toxicity (fibrosis and probably immunologically mediated pneumonitis), hepatotoxicity, thyroid gland dysfunction, corneal microdeposits, blue-grey skin discoloration and neurological disturbances. 

Hyatt RH, Sinha B, Vallon A, Bailey RJ, Martin A. Noncardiac side-effects of long-term oral amiodarone in the elderly. Age Ageing 1988 17(2) 116-22. 

An initial increase in cardiac arrhythmias (proarrhythmic effect) may occur when class III drugs are instituted. The most important proarrhythmia is known as torsades de pointes, which is a form of ventricular tachycardia that can be fatal.11,40 Specific class III agents are associated with various other side effects. Amiodarone, for example, is associated with pulmonary toxicity and liver damage. Other class III drugs may have a more favorable side-effect profile but may not be as effective as amiodarone in controlling arrhythmias. Side effects of class HI drugs there-... 

In the USA, amiodarone is approved for oral and intravenous use to treat serious ventricular arrhythmias. However, the drug is also highly effective for the treatment of supraventricular arrhythmias such as atrial fibrillation. Amiodarone has a broad spectrum of cardiac actions, unusual pharmacokinetics, and important extracardiac side effects. 

Cardiac side effects Torsade de pointes (<0.5%), severe bradycardia (one-year risk of bradycardia 2.4% on amiodarone vs. 0.8% on placebo). Non-cardiac side effects Pulmonary toxicity I % per year with fatal cases discontinue and treat symptomatically, hepatotoxicity... 

Amiodarone has a higher incidence of side effects than sotalol. Seventy-five percent of patients report side effects over 5 years with 15-35 percent requiring discontinuance of the drug. Severe adverse effects, including pulmonary fibrosis, can occur with usual doses of amiodarone and may be lethal or irreversible or persist for months after treatment is stopped. 

Adverse effects Amiodarone shows a variety of toxic effects. After long-term use, more than one half of the patients receiving the drug show side effects sufficiently severe to prompt its discontinuation. Some of the more common effects include interstitial pulmonary fibrosis, gastrointestinal tract intolerance, tremor, ataxia, dizziness, hyper- or hypothyroidism, liver toxicity, photosensitivity, neuropathy, muscle weakness, and blue skin discoloration caused by iodine accumulation in the skin. As noted earlier (see p. 166) recent clinical trials have shown that amiodarone did not reduce incidence of sudden death or prolong survival in patient with congestive heart failure (CHF). 

Heger JJ. Monitoring and treating side effects of amiodarone therapy. Cardiovasc Rev Rep 1988 9 47. 

Mantyjarvi M, Tuppurainen K, Ikaheimo K. Ocular side effects of amiodarone. Surv Ophthalmol 1998 42(4) 360-6. 

Dootson G, Byatt C. Amiodarone-indnced vascnlitis and a review of the cutaneous side-effects of amiodarone. Chn Exp Dermatol 1994 19(5) 422-4. 

Guccione P, Paul T, Garson A Jr. Long-term follow-up of amiodarone therapy in the young continued efficacy, unimpaired growth, moderate side effects. J Am CoU Cardiol 1990 15(5) 1118-24. 

Chronic therapy with amiodarone has been associated with pulmonary interstitial pneumonitis/alveolitis, hypersensitivity pneumonitis, and pulmonary fibrosis fatalities have resulted. Other side effects include elevated liver function tests, worsening of arrhythmias, onset of new arrhythmias, fatigue, tremor, involuntary movements, dizziness, paresthesias, difficulty in walking, hypothyroidism, hyperthyroidism, nausea, vomiting, constipation, anorexia, corneal... 

Amiodarone is a structural analog of thyroxine, and much of its toxicity is related to interactions that occur at thyroid hormone receptors. Pulmonary fibrosis is a frequent adverse effect tliat is related to dose, and drug level doses <200mg/day and maintenance of peak levels <2jLig/mL can help avoid this fife-threatening side effect. 

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