Volume 2 • Issue 9• 1000150
J Clinic Toxicol
ISSN: 2161-0495 JCT, an open access journal
Research Article Open Access
Ragab et al., J Clinic Toxicol 2012, 2:9
http://dx.doi.org/10.4172/2161-0495.1000150
Research Article Open Access
Clinical Toxicology
Clinical Utility of Serum Digoxin Level in Cardiac Patients for Diagnosis of
Chronic Digitalis Toxicity
Ahmed Refat Ragab
1,2
*, Maha Khalid Al-Mazroua
1,2
, and Rania Hamed Abdel-Rahman
1
1
Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Mansoura University, Egypt
2
Dammam Regional Poison Control Center-Eastern Region, Kingdom of Saudi Arab
*Corresponding author: Ahmed Refat Ragab, Department of Forensic Medicine
and Clinical Toxicology, Faculty of Medicine, Mansoura University, Egypt, E-mail:
ahmedrefat1973@yahoo.com
Received November 26, 2012; Accepted December 26, 2012; Published
December 28, 2012
Citation: Ragab AR, Al-Mazroua MK, Abdel-Rahman RH (2012) Clinical Utility of
Serum Digoxin Level in Cardiac Patients for Diagnosis of Chronic Digitalis Toxicity.
J Clinic Toxicol 2:150. doi:10.4172/2161-0495.1000150
Copyright: © 2012 Ragab AR, et al. This is an open-access article distributed
under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the
original author and source are credited.
Abstract
Digitalis toxicity is a complication of the digitalis therapy. It could occur also due to the patient taking in a much
larger dose of the drug than prescribed. The general symptoms of Digitalis toxicity are typically gastro-intestinal,
neurologic and non-specifc cardiac type manifestations that are strikingly similar to the clinical picture of primary
Congestive Heart Failure (CHF) making a diagnosis of chronic digitalis toxicity in particular relatively diffcult. Serum
digoxin measurement is today becoming a crucial subject of concern because of the narrow therapeutic window of
digoxin besides increasing mortality and morbidity due to its intoxication. The present work is focused on evaluating
the clinical value of Serum Digoxin Concentrations (SDCs) in relation to appropriate assessment of chronic digitalis
toxicity in cardiac patients. The current study was conducted in the form of a cross-sectional Electronic Medical
Record (EMR) review study of patients presently on continuous prescriptions for digoxin with there being zero
gaps in therapy for at least 10 days prior to SDC result entered into the Online Analytical Toxicology Request
Result (OTARR). There was also a complete clinical examination report as well as a review of the results of serum
potassium concentration, liver and kidney functions. Patients with digoxin toxicity (11.9%) had a signifcantly higher
mean SDC (2.75 ± 1.2) than those with subtherapeutic (0.67 ± 0.17 ng/mL) or eutherapeutic SDC (1.19 ± 0.26
ng/mL) (p value ≤ 0.05). About 12% of the total cases showed an abnormal serum potassium concentration of
electrolyte fuctuations. From this, one can conclude that a regular monitoring of serum digoxin level would be seen
as mandatory for the verifcation of digoxin’s therapeutic effects and then the subsequent prevention and early
diagnosis of chronic toxicity.
Keywords: Serum digoxin concentration; Cardiac patients; Digitalis
toxicity
Introduction
Digoxin, a purifed cardiac glycoside, is widely prescribed as
medications despite there being several adverse drug reactions due to it
[1]. Although digitalis preparations have been used therapeutically for
over two centuries, it is still quite difcult to diagnose digoxin toxicity.
Te various symptomatic indications with regard to toxicity are still
non-specifc, in the same way as are electrocardiographic changes. At a
specifc given Serum Digoxin Concentration (SDC) ‘Terapeutic’ and
‘toxic’ concentrations do overlap. For instance, a patient may be able to
control ventricular response without any adverse efects, while another
may exhibit toxicity. Terapeutic drug monitoring steps up the patient
care and are very likely a contributing factor to the suspected decrease
in digoxin toxicity; Yet, elevated concentrations are not the only reasons
for toxicity [2].
Tere is a tendency to overlook Digoxin intoxication because of its
variable bioavailability and because of diferences in its gastrointestinal
absorption, distribution and excretion [3]. Moreover, it has also shown
a narrow therapeutic window which could possibly heighten the risk
factors of toxicity in patients being treated with digoxin therapy with a
ratio of 5 to 35 % in hospitalized patients [4,5].
It was observed that in cardiac patients, the therapeutic range for
digoxin was in the range from 0.9 to 2.2 mg/ml [6]. Also, the serum
digoxin levels below and above this range were quite inefective and
toxic as well. Tere are many arrhythmias along with several other
extra cardiac side-efects, right from headaches, nausea and vomiting
to death [4].
According to a statement made by the American College of
Cardiology/American Heart Association (ACC/AHA) Guidelines for
Heart Failure in 2009, once the therapeutic range has been reached, it
is advisable to go in for SDC measurement. It is also considered proper
to bring about a change in a toxicity-provoking physiologic parameters,
like decreased renal function; afer the introduction or discontinuation
of an interacting drug; in order to assess clinical response; to assess
adherence; or in the presence of clinical signs of digoxin toxicity [7,8].
Te present work aims at evaluating the clinical value element of
Serum Digoxin Concentrations (SDCs) with regard to appropriate
assessment of chronic digitalis toxicity in cardiac patients at Dammam
Regional Poison Control Center.
Subjects and Methods
Study setting
Tis work was conducted as a cross sectional, (Electronic Medical
Review) EMR database review study at Damamm Regional Poison
Control Center–Eastern Region, KSA.
Inclusion criteria
Adult patients monitored for SDC in two hospitals (Dammam
Medical Complex and Qatif Central Hospital) that were participating