Amiodarone
From Ganfyd
Contents |
Individual drugs
Introduction
Amiodarone is a very useful antiarrhythmic agent in the short term but more problematical in long term use. The main short term problem is photosensitivity. It is a class III anti-arhythmic agent also with sodium and calcium-channel blocking actions as well as being a weak beta-blocker.
Clinical Use
Indications
Administration
Oral
IV Preferably given by a central line in 5% glucose as extravascularisation will lead to massive necrosis[1].
Clinical Issues
Toxicity
This is mainly long term and deserves to be well understood. The neurotoxic and hepatotoxic effects may be due to its inhibition of mitochondrial carnitine palmitoyltransferase I[2]. Amiodarone imposes a very large iodine load on the body and the topic of amiodarone associated thyroid disease is therefore complex.
- Thyroid disease
- Corneal microdeposits
- Pulmorary fibrosis (Acute pulmonary toxicity can also occur)
- Likely to be mitigated by ACE inhibitors and sartins[3]
- Neurotoxicity including tremor, ataxia, peripheral neuropathy, dyskinesia, myoclonic jerks, extrapyramidal increased tone, and altered mental status
- Liver damage
- Skin hyperpigmentation and photosenstivity
Contra-indications
Cautions and Interactions
Increases drug levels and thus potential for toxicity for many drugs including:
Side effects
Special advice
The following minimum safety monitoring at baseline and every six months on amiodarone if levels are within the population reference range:
- Thyroid profile (TSH, Free T4 and Free T3 where applicable)
- Liver enzymes (AST) and electrolytes (U&E)
- Clinical evaluation [1]
Pharmacology
References
- ↑ Russell SJ, Saltissi S. Amiodarone induced skin necrosis. Heart (British Cardiac Society). 2006 Oct; 92(10):1395.(Link to article – subscription may be required.)
- ↑ Kennedy JA, Unger SA, Horowitz JD. Inhibition of carnitine palmitoyltransferase-1 in rat heart and liver by perhexiline and amiodarone. Biochemical pharmacology. 1996 Jul 26; 52(2):273-80.
- ↑ Nikaido A, Tada T, Nakamura K, Murakami M, Banba K, Nishii N, Fuke S, Nagase S, Sakuragi S, Morita H, Ohe T, Kusano KF. Clinical features of and effects of angiotensin system antagonists on amiodarone-induced pulmonary toxicity. International journal of cardiology. 2008 Dec 22.(Epub ahead of print) (Link to article – subscription may be required.)
