Thrombopenic purpura following use of digitoxin

Adverse dermatologic effects of cardiovascular drug therapy: part II

Cardiovascular disease is common, affecting an increasing number of persons as the population ages. To combat this growing health problem, physicians use a multitude of medications in the treatment of their patients. Although pharmacologic therapy greatly enhances quality of life for a majority of patients, there is always the potential for an unfavorable reaction. For example, cardiovascular drugs can induce a vast array of adverse dermatologic responses. This article reviews the various cutaneous reaction patterns that can occur as a result of treatment with class III, IV, and other antiarrhythmic agents, ACE inhibitors, Angiotensin II receptor blockers, and diuretics.

Drug-induced thrombocytopenia in the coronary care unit

Drug-induced thrombocytopenia is a phenomenon that causes significant morbidity and mortality among patients. Practitioners should be able to recognize the clinical manifestations of drug-induced thrombocytopenia, differentiate it from other causes, and manage it appropriately. Numerous case reports have documented drug-induced causes of thrombocytopenia. The following article focuses on the characteristics and management of drug-induced thrombocytopenia secondary to medications commonly encountered in the coronary care unit. Pharmacotherapeutic agents that are most commonly implicated in this setting include ticlopidine, unfractioned heparin, glycoprotein (GP)IIb/IIIa inhibitors, H(2)-receptor antagonists, quinidine and antibiotics. Case reports were obtained through a comprehensive search of the Medicine database and subsequently complemented by bibliographic reviews of the agents just specified. Reports that exhibited possible, probable, and definite associations with drug-induced thrombocytopenia are included in the article.

Severe thrombocytopenia caused by digitoxin intoxication in a patient with heart failure associated with Sjögren's syndrome

Congestive heart failure (CHF) related to Sjögren's syndrome is extremely rare. This report concerns a patient who presented with CHF and severe thrombocytopenia (5,000/microl). Serum concentrations of K, Mg and digitoxin were 3.2mmol/L, 1.4mg/L and 57.2ng/ml, respectively. Digitoxin intoxication was evident, seemingly evoked by hypokalemia, hypomagnesemia, hepatorenal dysfunction and hypothyroidism. The severe thrombocytopenia was considered to have been caused by this intoxication, as it disappeared soon after the digitoxin was discontinued and potassium was supplemented.

Adverse dermatologic reactions from antiarrhythmic drug therapy

Undesirable cutaneous reactions to drugs may occur early or late in the course of treatment. The ingestion of drugs may also aggravate existing dermatologic conditions. The adverse dermatologic reactions from antiarrhythmic drug therapy are reviewed. The exact incidence of dermatologic side effects from cardiovascular drugs has been difficult to estimate because of sporadic reporting. In this review, the cutaneous side effects are discussed according to drug class and the type of dermatologic reaction.

Thrombocytopenia and drugs

Thrombocytopenia is a relatively common side effect of drug therapy. The pathogenetic mechanisms of drug-induced thrombocytopenia are varied and sometimes poorly understood. Immunologic and other cytotoxic effects may result in decreased production and/or increased destruction of platelets. The pathogenesis of drug-induced thrombocytopenia is reviewed. Diagnosis and treatment are also discussed.

Drug-induced thrombocytopenia

A variety of drugs may cause thrombocytopenia. Although it occurs more often than drug-induced anemia it is less well understood because techniques for studying drug-platelet-immune interactions have been unavailable until recently. The mechanisms by which drugs cause thrombocytopenia are varied. Bone marrow suppression or increased peripheral destruction of platelets could be involved. Nonimmunologic as well as immunologic mechanisms may also occur. These different mechanisms of drug-induced thrombocytopenia are reviewed. Diagnostic methods and treatment are also summarized.

Digitoxin intoxication with severe thrombocytopenia: reversal by digoxin-specific antibodies

As a result of overdosage a 77-year-old patient with heart disease developed digitoxin intoxication, associated with arrhythmias, extracardiac symptoms of intoxication and severe thrombocytopenia. Treatment with digoxin-specific antibody fragments relieved the signs and symptoms of intoxication within a few hours. The rise in platelet count from the pretreatment value of 26 000/mm3 to 47 000 within 12 h and to over 60 000/mm3 within 16 h of starting the antibody infusion may also be attributed to the treatment with antibodies. Such a rapid recovery from digitoxin-induced thrombocytopenia has not hitherto been described. Digoxin-specific antibodies, obtained by immunization of sheep with a digoxin-albumin conjugate, were used to treat intoxication with digitoxin, since cross-reaction had been demonstrated in vitro and in animal experiments. The present paper briefly discusses the mode of action and the general problems relating to the antibody therapy of digitalis poisoning.

Acute, massive poisoning with digitoxin: report of seven cases and discussion of treatment

Severe digitoxin poisoning in seven patients is reported. Doses taken varied from 2 to 20 mg, and maximal plasma concentrations of digitoxin from 50 to 237 nmol/L. One patient died from ventricular fibrillation, and the course in another was considerably protracted due to severe complications. The course in all patients was more dependent on underlying heart disease than on the plasma digitoxin concentration. Based on our own experiences and survey of the literature the following treatment is proposed: Gastric aspiration and lavage followed by instillation of activated charcoal should even be performed many hours after drug intake. In order to interrupt the enterohepatic circulation of digitoxin, repeated doses of charcoal should be given. Charcoal is preferable to cholestyramine because of its better tolerability. Ventricular arrhythmias should not be treated unless they are serious, because most antiarrhythmic drugs may further impede the AV-conduction. Phenytoin is the drug of choice, because the AV-conduction is less affected or even improved, and because the metabolism of digitoxin is accelerated. Conduction disturbances with bradycardia are frequently seen and may occur suddenly. Prophylactic introduction of a transvenous pacing catheter is therefore recommended as a routine procedure.

A patient with apparent idiopathic A-megakaryocytic thrombocytopenia

A 71-year-old woman developed life-threatening thrombocytopenia which resolved (probably spontaneously), recurred, and then again resolved. The thrombocytopenia was characterized by selective aphasia of megakaryocytes, near-normal platelet survival, and very slow recovery. No underlying disorder nor any drug could be incriminated, so we must assume this patient suffered from an idiopathic and very rare form of thrombocytopenia.