Applies to digoxin: compounding powder, injectable solution, oral capsule, oral elixir, oral tablet
Side effects generally have been dose-related and occurred more frequently when serum digoxin (the active ingredient contained in Lanoxin) levels exceed 2.0 ng/mL. Cardiovascular (50%), gastrointestinal (25%), and CNS symptoms (25%) have been reported most often.
Patients at increased risk include those with underlying renal, cardiopulmonary, or thyroid disease, electrolyte imbalances such as hypokalemia, hypomagnesemia, or hypercalcemia, and patients greater than 65 years of age.
Gastrointestinal side effects reported in 25% of patients have included anorexia, nausea, vomiting, diarrhea, and general abdominal pain. Rarely, intestinal ischemia or hemorrhagic necrosis, dysphagia, and esophageal dystonia have been reported.
Cases of severe abdominal pain and documented intestinal ischemia have been reported in patients after hemodialysis. Contraction of intravascular volume combined with digoxin-induced splanchnic vasoconstriction may induce abdominal pain.
Cardiovascular side effects have been reported the most frequently. These have included premature ventricular depolarizations (50%), AV nodal arrhythmias (50%), AV conduction disturbances (36%), wide complex tachycardia (less than 1%), paroxysmal atrial tachycardia with AV block, complete heart block, PR prolongation, and ST segment changes.
Ocular side effects have included chromatopsia, snowy or blurry vision, photopsia, and decreased visual acuity. Rarely, transient blindness has been reported. Decreased color vision has been reported.
The development of photopsia characterized by innumerable points of light in the peripheral visual fields or a decrease in visual acuity has been associated with therapeutic serum digitalis concentrations in the elderly. Digitalis-induced visual disturbances other than chromatopsia or disturbances of color vision may occur in elderly patients who have no other clinical manifestations of digitalis intoxication.
Digoxin-mediated inhibition of sodium-potassium ATPase influences normal uptake of extracellular potassium by Muller's cells and other retinal neurons and may result in decreased color vision.
Nervous system side effects reported in 25% of patients have included headache, dizziness, and weakness. At least one case of trigeminal neuralgia has been reported.
A 51-year-old man with ischemic cardiomyopathy complicated by congestive heart failure developed right trigeminal neuralgia associated with hyperalgesia between attacks. The pain resolved when digoxin was discontinued and reappeared upon rechallenge.
Psychiatric side effects have included decreased cognition, memory, disorientation, emotional lability, and depression.
A 74-year-old man with supraventricular tachycardia developed altered cognition, memory, and depression with a serum digoxin level of 0.9 ng/mL. Symptoms resolved when digoxin levels decreased to 0.5 ng/mL.
Endocrine side effects have included increased (significant) serum estrogen, decreased serum luteinizing hormone, decreased (significant) serum testosterone, and gynecomastia.
A study of 38 patients (20 postmenopausal women) who had taken digoxin for at least two years, revealed significantly decreased serum luteinizing hormone and testosterone levels and significantly increased serum estrogen levels relative to a control group of men and postmenopausal women. The study did not control for underlying disease and it is possible that the sex hormone alterations were associated with the underlying diseases rather than use of digoxin.
A 77-year-old man with congestive heart failure developed a psoriasiform rash associated with a positive macrophage inhibition factor test to digoxin (the active ingredient contained in Lanoxin) The rash resolved upon discontinuation of the drug and reappeared on rechallenge.
Hypersensitivity reactions have been reported rarely. At least one case of psoriasiform rash has been reported.
Hematologic side effects have been reported rarely. These have included thrombocytopenia.
A 60-year-old man with thyroid cancer and supraventricular tachycardia developed reversible thrombocytopenia during digoxin and heparin therapy. The thrombocytopenia resolved when digoxin alone was discontinued. The bone marrow examination and immunological studies were consistent with a digoxin-induced immune thrombocytopenia due to circulating immune complexes.
Three patients with Type II diabetes who experienced greater antidiabetic control and significant reduction in requirements of hypoglycemic agents following discontinuation of digoxin (the active ingredient contained in Lanoxin) has been reported. Rechallenge in one patient resulted in increased glucose levels and subsequent dosage increases of hypoglycemic agents.
Metabolic side effects have included hypokalemia, hypomagnesemia, and hypercalcemia. Diabetes mellitus and glucose intolerance have been reported.
Dermatologic side effects have been reported rarely. These have included maculopapular rash and other nonspecific skin reactions.
Other side effects have been reported rarely. At least one case of diaphoresis and malaise has been reported. At least one case of digoxin (the active ingredient contained in Lanoxin) cachexia, fatigue, weight loss, and decreased appetite has been reported.
A 48-year-old man with rheumatic mitral valve disease and atrial flutter/fibrillation developed profound diaphoresis and malaise associated with a serum digoxin level of 0.7 ng/mL. The symptoms resolved when digoxin was discontinued, and reappeared on rechallenge.
Cachexia, fatigue, and documented weight loss have been reported in rare cases. Appetites and weights improved after discontinuation of digoxin.