Amitava Dasgupta PhD

Contents

1. Therapeutic Drug Monitoring of Digoxin

2. Discovery of Endogenous DLIS

3. Positive and Negative Interference of DLIS in Serum Digoxin Measurement: Impact on TDM of Digoxin

4. Is DLIS a Natriuretic Hormone?

5. Effect of Fab Fragment of Antidigoxin Antibody on Digoxin Immunoassays

6. Interference of Spironolactone, Potassium Canrenoate, and Canrenone in Digoxin Assays

7. Interference of Complementary and Alternative Medicines in Digoxin Measurement

8. Conclusions

Summary

Digoxin is a cardioactive drug with a narrow therapeutic range. Both endogenous and exogenous compounds interfere with the determination of digoxin in serum by using immunoassays. Endogenous compounds are termed as digoxin-like immunoreactive substances (DLIS) and elevated DLIS concentrations are encountered in volume-expanded patients such as those with uremia, essential hypertension, liver disease, and preeclampsia. DLIS cross-reacts with anti-digoxin antibodies and may falsely elevate (positive interference) or falsely lower (negative interference) serum digoxin concentrations, thus causing problems in interpreting results. Exogenous compounds that interfere with digoxin assays are various Chinese medicines such as Chan Su, Lu-Shen Wan, and oleander-containing herbal preparations. Therapy with spironolactone, canrenone, or potassium canrenoate may also interfere with digoxin immunoassays. However, endogenous DLIS as well as components of various Chinese medicines are strongly protein bound whereas digoxin is weakly protein bound (25%). Taking advantage of the differences in protein

From: Handbook of Drug Monitoring Methods Edited by: A. Dasgupta © Humana Press Inc., Totowa, NJ

binding, interference of both endogenous DLIS and Chinese medicines in serum digoxin measurement can be mostly eliminated by monitoring digoxin concentrations in the protein-free ultrafiltrates. Monitoring free digoxin also eliminates spironolactone interference (if used in moderate dosage) in serum digoxin measurement using immunoassay.

Key Words: Digoxin; DLIS; Chinese medicines; spironolactone; free digoxin.

Chinese Herbs

Chinese Herbs

Worried For Your Health More Than Ever? Want To PREVENT Rather Than CURE Your Illness? Then WE are the only ones who can answer YOUR concern of time by presenting the exclusive work piece, the explicit and special eBook on CHINESE HERBS- the call of time.

Get My Free Ebook


Post a comment