Amiodarone
- Class: Antiarrhythmic
- Used for: irregular heartbeat
- Say it: am-ee-OH-duh-rohn
- Forms: tablet, injection
AMIODARONE has IODINE sitting in the middle of its name — and the thyroid is what pays for it.
The molecule really is iodine-rich. That is why it causes both over- and under-active thyroid, and why thyroid tests every six months are not optional.
Formally a class III potassium-channel blocker, it also blocks sodium channels, calcium channels and beta receptors. That breadth is why it works when others fail, and why it damages thyroid, lung, liver, eye and skin.
Side effects
Common: nausea, sun sensitivity, blue-gray skin
Serious: thyroid disease, lung fibrosis
Typical dose
200 mg three times daily for a week, then tapered to 200 mg once daily
Loading is unavoidable — with a half-life near 50 days, an unloaded dose would take months to reach steady state.
Check yourself
Which monitoring does long-term amiodarone require?
- Thyroid and liver function, with lung and eye surveillance
- Potassium alone
- Nothing routine — it is well tolerated long-term
- Weekly full blood counts
Show answer
A. Thyroid and liver function, with lung and eye surveillance
Amiodarone's iodine-rich structure and very long half-life let it accumulate in several tissues at once. Thyroid (both over- and under-active), liver, lung and cornea are all affected, which is why its follow-up is broader than for any other antiarrhythmic.
See it, don't memorize it
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