Lanoxin (Digoxin) - Side Effects and Adverse Reactions

ADVERSE REACTIONS

In general, the adverse reactions of digoxin are dose-dependent and occur at doses higher than those needed to achieve a therapeutic effect. Hence, adverse reactions are less common when digoxin is used within the recommended dose range or therapeutic serum concentration range and when there is careful attention to concurrent medications and conditions.

Because some patients may be particularly susceptible to side effects with digoxin, the dosage of the drug should always be selected carefully and adjusted as the clinical condition of the patient warrants. In the past, when high doses of digoxin were used and little attention was paid to clinical status or concurrent medications, adverse reactions to digoxin were more frequent and severe. Cardiac adverse reactions accounted for about one-half, gastrointestinal disturbances for about one-fourth, and CNS and other toxicity for about one-fourth of these adverse reactions. However, available evidence suggests that the incidence and severity of digoxin toxicity has decreased substantially in recent years. In recent controlled clinical trials, in patients with predominantly mild to moderate heart failure, the incidence of adverse experiences was comparable in patients taking digoxin and in those taking placebo. In a large mortality trial, the incidence of hospitalization for suspected digoxin toxicity was 2% in patients taking LANOXIN compared to 0.9% in patients taking placebo. In this trial, the most common manifestations of digoxin toxicity included gastrointestinal and cardiac disturbances; CNS manifestations were less common.

Adults

Cardiac

Therapeutic doses of digoxin may cause heart block in patients with pre-existing sinoatrial or AV conduction disorders; heart block can be avoided by adjusting the dose of digoxin. Prophylactic use of a cardiac pacemaker may be considered if the risk of heart block is considered unacceptable. High doses of digoxin may produce a variety of rhythm disturbances, such as first-degree, second-degree (Wenckebach), or third-degree heart block (including asystole); atrial tachycardia with block; AV dissociation; accelerated junctional (nodal) rhythm; unifocal or multiform ventricular premature contractions (especially bigeminy or trigeminy); ventricular tachycardia; and ventricular fibrillation. Digoxin produces PR prolongation and ST segment depression which should not by themselves be considered digoxin toxicity. Cardiac toxicity can also occur at therapeutic doses in patients who have conditions which may alter their sensitivity to digoxin (see WARNINGS and PRECAUTIONS).

Gastrointestinal

 Digoxin may cause anorexia, nausea, vomiting, and diarrhea. Rarely, the use of digoxin has been associated with abdominal pain, intestinal ischemia, and hemorrhagic necrosis of the intestines.

CNS

  Digoxin can produce visual disturbances (blurred or yellow vision), headache, weakness, dizziness, apathy, confusion, and mental disturbances (such as anxiety, depression, delirium, and hallucination).

Other

  Gynecomastia has been occasionally observed following the prolonged use of digoxin. Thrombocytopenia and maculopapular rash and other skin reactions have been rarely observed.

Table 4 summarizes the incidence of those adverse experiences listed above for patients treated with LANOXIN Tablets or placebo from 2 randomized, double-blind, placebo-controlled withdrawal trials. Patients in these trials were also receiving diuretics with or without angiotensin-converting enzyme inhibitors. These patients had been stable on digoxin, and were randomized to digoxin or placebo. The results shown in Table 4 reflect the experience in patients following dosage titration with the use of serum digoxin concentrations and careful follow-up. These adverse experiences are consistent with results from a large, placebo-controlled mortality trial (DIG trial) wherein over half the patients were not receiving digoxin prior to enrollment.

Table 4. Adverse Experiences In 2 Parallel, Double-Blind, Placebo-Controlled Withdrawal Trials (Number of Patients Reporting)

Adverse Experience	Digoxin Patients (n = 123)	Placebo Patients (n = 125)
Cardiac
Palpitation	1	4
Ventricular extrasystole	1	1
Tachycardia	2	1
Heart arrest	1	1
Gastrointestinal
Anorexia	1	4
Nausea	4	2
Vomiting	2	1
Diarrhea	4	1
Abdominal pain	0	6
CNS
Headache	4	4
Dizziness	6	5
Mental disturbances	5	1
Other
Rash	2	1
Death	4	3

Infants and Children

 The side effects of digoxin in infants and children differ from those seen in adults in several respects. Although digoxin may produce anorexia, nausea, vomiting, diarrhea, and CNS disturbances in young patients, these are rarely the initial symptoms of overdosage. Rather, the earliest and most frequent manifestation of excessive dosing with digoxin in infants and children is the appearance of cardiac arrhythmias, including sinus bradycardia. In children, the use of digoxin may produce any arrhythmia. The most common are conduction disturbances or supraventricular tachyarrhythmias, such as atrial tachycardia (with or without block) and junctional (nodal) tachycardia. Ventricular arrhythmias are less common. Sinus bradycardia may be a sign of impending digoxin intoxication, especially in infants, even in the absence of first-degree heart block. Any arrhythmia or alteration in cardiac conduction that develops in a child taking digoxin should be assumed to be caused by digoxin, until further evaluation proves otherwise.

REPORTS OF SIDE EFFECTS / ADVERSE REACTIONS RELATED TO LANOXIN

Possible Lanoxin side effects / adverse reactions in 69 year old female

Reported by a consumer/non-health professional from United States on 2007-01-05

Patient: 69 year old female

Reactions: Cataract, Skin Exfoliation, DRY Skin, Halo Vision

Suspect drug(s):
Lanoxin
    Administration route: Oral
    Indication: Atrial Fibrillation

Amiodarone HCL
    Dosage: 200mg twice per day
    Administration route: Oral
    Indication: Atrial Fibrillation

Other drugs received by patient: Coumadin; Levothyroxine Sodium; Mirapex; Torsemide; Xanax; Calcium + Vitamin D; Folic Acid; Multi-Vitamin; Toprol-XL

Possible Lanoxin side effects / adverse reactions in 93 year old female

Reported by a consumer/non-health professional from Italy on 2007-01-10

Patient: 93 year old female

Reactions: Therapeutic Agent Toxicity, Atrioventricular Block, Peripheral Ischaemia

Adverse event resulted in: hospitalization

Suspect drug(s):
Lanoxin
    Dosage: .06mg per day
    Administration route: Oral
    Start date: 2006-01-01
    End date: 2006-10-16

Isoptin
    Dosage: 160mg per day
    Administration route: Oral
    Indication: Atrial Fibrillation
    Start date: 2006-01-01
    End date: 2006-10-16

Other drugs received by patient: Allopurinol TAB; Lasix; Minitran; Tavor; Cardirene; Mepral; Spironolactone

Possible Lanoxin side effects / adverse reactions in 79 year old female

Reported by a consumer/non-health professional from Italy on 2007-01-25

Patient: 79 year old female

Reactions: Dyspnoea, Chest Pain

Adverse event resulted in: hospitalization

Suspect drug(s):
Lanoxin

Other drugs received by patient: Aspirin; Frusemide; Spironolactone + Frusemide