Cardiac glycoside toxicity resulting from cough linctus abuse

Proprietry cough medicines are often abused by drug addicts as they are freely available and, in many instances, contain narcotic substances. A variety of other compounds are present in these products, including compounds structurally related to the commonly prescribed cardiac glycosides. We report a case in which severe cardiac glycoside toxicity resulted from the abuse of such a preparation.

The role of intracellular Ca ions in the therapeutic and toxic effects of cardiac glycosides and catecholamines

Many inotropic maneuvers act by increasing the intracellular calcium concentration [( Ca2+]i). The present report illustrates this with respect to the positive inotropic effects of cardiac glycosides and catecholamines. It is shown that the increased contractility produced by cardiac glycosides is accompanied by an increase in intracellular Na concentration and, furthermore, that the relationship between contraction and Na is very steep. This steep dependence, which may result from a Na-Ca exchange which exchanges several Na ions per Ca, means that maneuvers that have only small effects on Na will have significant effects on contraction. Cardiac glycosides also produce abnormal pacemaker activity and cardiac arrhythmias. These originate from a transient inward current activated by oscillations of [Ca2+]i, which result from spontaneous oscillatory release of Ca ions from the sarcoplasmic reticulum. The local anesthetic group of antiarrhythmic agents abolishes the transient inward current. Catecholamines also increase systolic [Ca2+]i and, in high enough concentrations, can produce oscillations of [Ca2+]i. This tendency of glycosides and catecholamines to produce arrhythmogenic oscillations of [Ca2+]i is a major limitation to their use. Therefore, inotropic agents that act by means other than increasing [Ca2+]i may be of great efficacy.

[Effect of cardiac glycosides on whole body potassium concentration in circulatory insufficiency]

Variation of potassium levels produced by cardiac glycosides was assessed in patients with 1st- to 3d-stage circulatory insufficiency, by means of 40K radioactivity measurement in a low radioactivity background chamber. Total group figures demonstrated that total body potassium levels increased with the improvement of the patients' clinical condition. Total body potassium decreased in patients showing signs of cardiac glycoside intoxication. The analysis of the data with reference to pre-and post-treatment baseline tissue potassium concentrations, as compared to the desired level, showed tissue potassium to normalize under the effect of cardiac glycosides in cases of initially abnormal values, and to decrease irrespective of the initial values in cases of cardiac glycoside intoxication.

[Autoimmunity induced by drugs. Immunological characteristics and etiopathogenic hypotheses]

Drug-induced autoimmune diseases have two immunological peculiarities. Firstly, some autoantibodies are present, which are virtually never seen in spontaneous human diseases and may be regarded as specific. This applies to antimitochondria antibody type 3 (anti M3) in the lupus-like syndrome caused by Venocuran, to antimitochondria antibody type 6 (anti M6) in iproniazide-induced hepatitis, to anti-insulin antibody found after treatment with methimazole, and to anti liver/kidney microsome antibody type 2 (anti LKM2) associated with hepatitis induced by tielinic acid. Secondly, a search for other autoantibodies shows that the immune disorder is much more limited than in spontaneous autoimmune diseases. Thus, contrary to myasthenia and idiopathic autoimmune haemolytic anaemia, we never found autoantibodies specifically directed against the thyroid, the stomach or the adrenal gland during treatment with D-penicillamine and alpha-methyldopa. Only some hypotheses may account for these peculiarities. Cross-reaction between drug and autoantigen may occur, but the fact that the antigen-antibody reaction is not inhibited by the drug or its metabolites does not support this explanation. Much more attractive is the "T-cell bypass" theory, according to which autoreacting suppressor T-cells are circumvented by helper T-cells stimulated by the drug-modified autoantigen. In this case, the autoimmune reaction would indicate to which body substance the drug is bound, thus making it immunostimulant, and not a structural similarity between the drug and the autoantigen.

Medication problems among outpatients. A study with emphasis on the elderly

When patients ascribe adverse symptoms to their medications, the medical care process can be affected. To investigate how often medical outpatients link various adverse symptoms with their medications and to learn what actions they take in response, 299 randomly selected medical outpatients were interviewed. Thirty percent of the subjects identified at least one medication as causing an undesirable symptom. Subjects 65 years or older attributed a lower mean number of adverse symptoms to their medications than did younger subjects. Subjects rarely reported modifying their medication regimens due to adverse symptoms, a finding supported by multiple regression analysis. Approximately one in four subjects did not discuss their symptoms with their providers. These results have important implications for medical care in general, and for the elderly in particular.

[Acute fatal non-occlusive intestinal ischemia during treatment with a cardiotonic glucoside]

After presenting the case of a 70 year old woman who presented a massive mesenteric infarction as a result of non-occlusive intestinal ischaemia ( NOII ), the authors review the principal features of this particular form of intestinal ischaemia. This condition is seen principally in elderly people with a syndrome of low cardiac output, resulting in marked mesenteric vasoconstriction. It is a complication of either severe decompensated heart disease treated with digitaloids or to a state of hypovolaemic or septic shock. The diagnosis of NOII should be suggested by the combination of abdominal signs with a state of shock and/or treated heart disease. The diagnosis is confirmed by selective mesenteric arteriography which reveals a patent but spastic vessel. The treatment is initially medical, consisting of the correction of haemodynamic disturbances and the in situ injection of vasodilator products, which may need to be completed by a surgical operation. However, the prognosis of NOII remains serious, particularly because of the frequent delay in making the diagnosis.

Therapeutic range of cardiac glycosides

The narrow therapeutic range of cardiac glycosides continually challenges chemists to synthetize new derivatives with improved therapeutic properties. One of the best investigated semi-synthetic glycosides is 16 alpha-gitoxin. Compared to ouabain and gitoxin, it produces positive inotropic effects on the isolated guinea-pig heart in a wider range of concentrations and causes less pronounced rhythmic disturbances. These results were confirmed by electrophysiological investigations in isolated fibres of the canine myocardium and of the Purkinje system, by investigations in the anaesthetized cat and dog and in healthy volunteers. The effects of various semi-synthetic compounds (e.g. actodigin, ASI-222) are described and possibilities to trigger these effects are discussed. Of some significance seem to be differences in the structure of the (Na+ + K+)-ATPase system of different tissues, e.g. the working muscle and the Purkinje system of the heart, as well as differences due to the formation and dissociation of the glycoside-enzyme complex. The significance of K+, Ca2+ and of several pharmacokinetic parameters (e.g. the volume of distribution) for these reactions are briefly discussed.

[Drug incompatibility in the aged]

Geriatric patients often have several diseases so that in the acute phase the doctor has to treat with many drugs simultaneously. Elderly persons are more vulnerable to drug effects, both therapeutic and adverse. Physiological and pathological changes with aging influence geriatric drug therapy. Pharmacokinetic differences are generally consistent with age differences in renal and liver function, body composition, tissue perfusions, protein and cellular binding. The present paper gives some examples (glycosides, anticoagulants) of drug therapy and adverse reactions.

[Indications and contraindications for therapy with cardiac glycosides]

Today glycosides have 3 indications: manifest and chronic cardiac insufficiency, arrhythmia absoluta and paroxysmal supraventricular tachycardia. Glycosides are no longer important in the therapy of acute cardiac insufficiency. There are also absolute and relative contraindications which should be recognized; in coronary heart disease glycosides should only be used if there is really a latent of manifest cardiac insufficiency.

[Hemodynamic examinations concerning the effects of cardiac glycosides in hypertrophic obstructive cardiomyopathy (HOCM)]

Due to fundamental considerations and especially after Braunwald's et al. (1962 (4)) examinations of 5 patients with severe hypertrophic obstructive cardiomyopathy (HOCM) with 0.5-0.75 mg of Ouabain, cardiac glycosides in cases of this disease are to be regarded as contraindicated. Own examinations (right and left-heart catheterizations, monoplane cineangiography of the left ventricle, determination of the cardiac output, and the ejection fraction (EF) were performed in 10 patients with HOCM of different stages. Applying the usual dosage of 0.25-0.375 mg of strophanthin, different hemodynamic effects were observed in discrete forms. In cases with a higher severity, the observations of Braunwald et al. could actually be confirmed. The left ventricular systolic pressure gradients were increased, but cardiac output, left ventricular enddiastolic pressure, pulmonary pressure and resistance, and also arterial pressure and peripheral resistance behaved differently. EF increased slightly. The right infundibular gradients were decreased with one exception, or resp., they were unchanged. Obviously, HOCM reacts especially unfavourably with so-called left-ventricular cavity obliteration. The main importance might belong to the behaviour of the free lumen of the left ventricle. In regard of the principally reserved attitude towards the cardiac glycoside therapy in HOCM, no change has occurred. Only in patients with atrial fibrillation and a rapid heart rate, a therapy trial could be considered, if necessary in combination with beta-blocking agents or calcium antagonists under hemodynamic control. In cases of HOCM with serious obstruction and signs of cardiac failure and inadequate affecting by calcium antagonists, an early surgical intervention should be executed.

Adverse effects of cardiovascular drug therapy on the fetus and neonate

Possible adverse effects of cardiovascular medications on the fetus and the neonate have been reviewed. The major classes discussed were diuretics, antihypertensives, antiarrhythmics, cardiac glycosides, and anticoagulants. The recommendations given must not be considered definitive because they are based on flawed or incomplete information. It is to be hoped that further investigation will improve this situation and will also improve our understanding of the ways in which these drugs act.

[Pseudo-(venocuran-)lupus--a minor episode in the history of medicine]

Pseudolupus is a syndrome characterized by recurrent fever arthralgia, myalgia, involvement of lung and heart, high sedimentation rate, leukocytosis and lymphopenia. The diagnosis is established by the presence of circulating antimitochondrial antibodies. In 1975 it was found that the disease was due to prolonged treatment with Venocuran, a drug against venous disorders composed of phenopyrazone (pyrazolone derivative), horse-chestnut extract, and Miroton (glycosides extracted from white squill [Urginea maritima], convallaria, oleander and adonis). The drug was then withdrawn. No new cases have come to our attention since then. 15 patients with severe pseudolupus known to us in 1975 have now been followed up. In 6 of the patients all symptoms disappeared within weeks or a few months after withdrawal of the drug. However, the other 9 patients had at least 1 and often 2--3 relapses in the following months to years. In some patients, symptoms remained as long as 4--5 years. Antimitochondrial antibodies persisted in 4 patients for more than 3 years and in 1 patient are still detectable now. The pathomechanism of pseudolupus has not been elucidated.