Concentrations of Amiodarone in Fat Tissue During Chronic Treatment

Study Overview
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Brief Summary
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The objective of this study is to determine if concentrations of amiodarone in fat tissue increases constantly over time during chronic treatment with this drug, and if blood concentrations reflect accurately the concentrations in fat tissue or not. This is because excessive concentrations of this drug in tissues can produce adverse effects.

Detailed Description
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Amiodarone is very effective to treat cardiac arrhythmias but its use is limited by its toxicity, specially in chronic treatment. Accumulation of the drug in tissues is very probably the cause of the majority of amiodarone delayed adverse effects. However, this has not been proved because obtaining tissue samples is usually difficult and aggressive. The investigators study, in patients following chronic treatment with amiodarone, if needle aspiration can provide samples of fat tissue useful to accurately determine amiodarone concentrations, how those concentrations in fat tissue correlate with cumulated dose, and how concentrations in fat tissue correlate with concentrations in blood, which is easier to obtain. The investigators expect this knowledge will help to understand how amiodarone develops its adverse effects and possibly lead to new ways of monitoring treatment with this drug, or to adapt doses in chronic administration.

Official Title
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Study of Concentrations of Amiodarone in Fat Tissue Obtained by Needle Aspiration in Patients on Chronic Treatment

Conditions
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Arrhythmia, Atrial Fibrillation, Atrial Flutter

Intervention / Treatment
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* Procedure: Fat tissue needle aspiration


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients taking amiodarone for more than 3 months (any dose, any indication) Exclusion Criteria: Impossibility to perform needle aspiration of abdominal wall (local infection, skin disease) Coagulation disorders, INR > 3.0 if warfarin treatment Patient unable to give informed consent

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Amiodarone, long-term<br>Unique arm: all patients were taking amiodarone for more than 6 months and all patietns underwent amiodarone dosage in blood and fat tissue samplings | Procedure: Fat tissue needle aspiration<br>* Small fat tissue sampling performed by needle aspiration.<br>* Other names: Adipose subcutaneous tissue biopsy;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Relationship Between Amiodarone Concentration in Fat Tissue and Cumulated Dose. | Correlation between amiodarone concentration in fat tissue (mean from several sampling points) and cumulated dose. | One single measure | 
| Relationship Between Amiodarone Concentrations in Fat Tissue and in Plasma. | Correlation between amiodarone concentrations in fat tissue (mean of 2 samples) and simultaneous concentration in plasma. | One single measure, taken just before daily administration | 
| Relationship Between Amiodarone Concentrations in Fat Tissue and Developing Adverse Effects. | Relationship between amiodarone concentrations in fat tissue (mean of two different samplings and developping adverse effects. | Cumulated time on amiodarone (varies in each patient) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain and Complications (if Any) Caused by Fat Tissue Needle Aspirations | Number of patients having complications (if any) caused by fat tissue needle aspirations | 24 hours after needle aspiration | 
| Presence of Any Adverse Effect Attributable to Amiodarone. | Number of patients developing adverse effects by amiodarone leading to withdrawal or specific treatment (i.e. thyroid hormone treatment) | Cumulated time on amiodarone (varies in each patient) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Anti-Arrhythmia Agents, Amiodarone, chronic treatment, Amiodarone, adverse effects, Biopsy, Fine-Needle, Adipose tissue, Drug concentrations in tissues, Drug accumulation in tissues