digoxin and Cat-Diseases

Topics: Animals; Cardiotonic Agents; Cat Diseases; Cats; Digoxin; Dog Diseases; Dogs; Heart Failure; Humans

Topics: Animals; Cardiomyopathies; Cat Diseases; Cats; Diet, Sodium-Restricted; Digoxin; Electrocardiography; Furosemide; Heart Diseases; Heart Failure; Lidocaine; Propranolol; Thromboembolism

Between October 1986 and September 1988, 37 cats with moderate to severe idiopathic myocardial failure (dilated cardiomyopathy) were evaluated. Clinical management of these cats was similar to that described in the literature, except that it also included administration of 500 or 1,000 mg of the sulfur amino acid, taurine per day. Early death (death within the first 30 days of treatment) occurred in 14 (38%) cats. One cat was lost to follow-up evaluation. Twenty-two cats (59%) had marked clinical and echocardiographic improvement and survived longer than 240 days. In all but 1 cat, the observed improvement in echocardiographic measurements persisted. Hypothermia and thromboembolism were positively associated with an increased risk of early death. Administration of digoxin did not significantly affect survival. All 22 cats that survived greater than 30 days remained clinically stable despite withdrawal of all medications except taurine. Administration of taurine was eventually discontinued in 20 of the 22 cats and adequate taurine intake was thereafter provided for in the food. The clinical response and 1-year survival rate of 58% (21 of 36 cats with a known outcome) in the taurine-treated group represents a marked improvement, compared with a 1-year survival rate of 13% (4 of 31 cats with a known outcome) in a retrospectively evaluated population of 33 cats with dilated cardiomyopathy.

Topics: Animal Feed; Animals; Cardiomyopathy, Dilated; Cat Diseases; Cats; Digoxin; Echocardiography; Follow-Up Studies; Heart Murmurs; Prospective Studies; Regression Analysis; Retrospective Studies; Risk Factors; Taurine

Topics: Animals; Cardiomyopathy, Dilated; Cat Diseases; Cats; Diagnosis, Differential; Digoxin; Enalapril; Furosemide; Heart Failure; Male; Nitroglycerin; Oxygen Inhalation Therapy; Radiography; Ultrasonography

Responses (473) were collated from a questionnaire sent to 5054 veterinarians in Australia enquiring about drug preferences for treating cardiac disease in dogs and cats. When treating a small breed dog with endocardiosis and mild left congestive heart failure, 74% of 472 respondents used a diuretic, 67% a theophylline derivative, 27% a vasodilator and 20% a positive inotrope. Frusemide was the preferred diuretic and digoxin the preferred inotrope, but vasodilator use varied. Low sodium diets were "often recommended" by 71% of respondents. Propranolol was preferred to diltiazem for treating feline hypertrophic cardiomyopathy. Digoxin was clearly preferred for treating supraventricular dysrhythmias, while lignocaine and digoxin were preferred equally for ventricular dysrhythmias. Respondents appeared more willing than US veterinarians to use theophylline derivatives and prasozin, and less inclined to employ nitrates, hydralazine, inotropes other than digoxin, and low sodium diets.

Topics: Animals; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Australia; Cardiotonic Agents; Cardiovascular Agents; Cat Diseases; Cats; Digoxin; Diuretics; Dog Diseases; Dogs; Furosemide; Heart Diseases; Heart Failure; Lidocaine; Propranolol; Surveys and Questionnaires; Vasodilator Agents

The role of digoxin in treatment of cats with dilated cardiomyopathy and other forms of myocardial failure is unclear. We evaluated the chronotropic and inotropic effects of digoxin by comparing baseline, noninvasive indices of cardiac performance with those obtained after 9 +/- 1.3 (mean +/- SEM) days of digoxin treatment in 6 cats with heart failure attributable to dilated cardiomyopathy. Two-dimensionally directed, M-mode echocardiography and electrocardiography were used to determine left ventricular shortening fraction, preejection period (PEP), ejection time (LVET), PEP to LVET ratio, velocity of circumferential fiber shortening, electromechanical systole, heart rate, and PR interval. Treatment consisted of administration of furosemide (mean dosage, 2.4 mg/kg of body weight/day), digoxin in tablet form (approximately 0.01 mg/kg, q 48 h), aspirin (80 mg, q 48 h), and a commercial low-salt diet. In addition, 2 cats were administered short-term, low-dose fluids IV, and 2 were given taurine supplementation at rates of 500 and 1,000 mg/day. Other off-loading or inotropic agents were not administered. Therapeutic or toxic serum digoxin concentration was achieved in all cats. Significant (P less than 0.05) improvement was detected in mean values for shortening fraction, PEP, PEP to LVET ratio, and velocity of circumferential fiber shortening. Mean electromechanical systole and LVET did not change significantly. Improvement, as assessed by indices of cardiac function, was documented in 4 of the 6 cats treated with digoxin, including the 2 cats given taurine supplementation. In the cats given taurine, positive inotropic effect was observed prior to the time when taurine-induced improvement in ventricular function is detectable.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Cardiomyopathy, Dilated; Cat Diseases; Cats; Combined Modality Therapy; Diet, Sodium-Restricted; Digoxin; Echocardiography; Electrocardiography; Female; Furosemide; Heart Rate; Male; Taurine

To evaluate the effects of compensated heart failure (HF) on digoxin pharmacokinetic properties in cats, 6 cats with dilated cardiomyopathy were compared with 6 clinically normal (control) cats. Digoxin tablets were administered at a dosage of 0.01 mg/kg of body weight, q 48 h for approximately 10 days, until presumed steady state was reached. Both groups were treated concomitantly with aspirin, furosemide, and a commercial low-salt diet. Retrospectively, control and HF cats were calculated to be at 95% and 97% steady state, respectively. At the time blood samples were collected, HF cats were clinically compensated. Serum digoxin concentration [( DXN]) was determined by radioimmunoassay on samples drawn immediately before and 1, 2, 4, 8, 12, 24, 34, and 48 hours after digoxin administration. Measured and calculated values (peak, 8-hour, and mean [DXN]; elimination half-life [t1/2]; oral clearance; and hours during which [DXN] was in the toxic range) were not significantly different between control and HF cats. To predict individual propensity for digoxin intoxication, serum creatinine and urea concentrations and sulfobromophthalein dye retention were measured in control and HF cats prior to the onset of treatment with digoxin. There was no statistically significant correlation between serum creatinine and urea concentrations when compared with sulfobromophthalein dye retention nor between any of these values and digoxin peak, 8-hour, and mean concentrations or t1/2, oral clearance, or hours during which [DXN] was in the toxic range. Mean serum creatinine and urea nitrogen concentrations were significantly greater (P less than 0.01) and sulfobromophthalein dye retention approached significant prolongation (P less than 0.06) in HF cats, compared with that in control cats.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Blood Urea Nitrogen; Cardiomyopathy, Dilated; Cat Diseases; Cats; Creatinine; Digoxin; Female; Male

Ventricular preexcitation was diagnosed in 6 dogs and 7 cats examined because of weakness, syncope, or congestive heart failure, and as an incidental finding in 1 dog and 2 cats. Reciprocating tachycardias were documented in 8 of the cases. Six of the cats had a pathologic diagnosis of primary cardiomyopathy. Two of the dogs had an associated congenital heart defect. Reciprocating tachycardias were controlled in 4 cases with digoxin, in 2 cases with propranolol, and in 1 case with quinidine. Conduction through the accessory pathway was altered by quinidine (2 cases), digoxin, and propranolol (1 case each), resulting in a lengthened P-R interval and more normal QRS complex configuration.

Topics: Animals; Cat Diseases; Cats; Digoxin; Dog Diseases; Dogs; Electrocardiography; Female; Male; Pre-Excitation Syndromes; Propranolol; Quinidine; Tachycardia

The biological half-life of digoxin was 33.3 +/- 9.5 hours in 6 cats after a single IV injection. Longer half-lives were obtained after chronic oral administration, indicating that digoxin elimination is capacity-limited in the cat. The mean percentage of urinary excretion of digoxin after a single IV dose was 45% +/- 9.7% over a 10-day period. Toxic plasma concentrations ranged from 2.4 to 2.9 ng/ml, and 5 of 6 cats had clinical signs of toxicosis at concentrations greater than 2.6 ng/ml. Prolongation of the PQ interval was seen on the ECG at nontoxic plasma concentrations in 4 of 6 cats. The most striking ECG evidence of digoxin toxicosis was ST-segment elevation seen in 3 of the 6 cats.

Topics: Administration, Oral; Animals; Cat Diseases; Cats; Digoxin; Electrocardiography; Female; Half-Life; Heart; Injections, Intravenous; Kinetics; Male

Nonanesthetized cats of both sexes were given oral digoxin (0.011 mg/kg of body weight) 3 forms: elixir, tablet, and crushed tablet mixed with food. Mean peak plasma concentrations of digoxin were highest with the elixir (1.89 +/- 1.02 ng/ml) and lowest with the crushed tablet mixed with food (0.66 +/- 0.35 ng/ml). Male cats had significantly higher (P less than 0.10) mean plasma digoxin concentrations than did female cats. A 2nd group of nonanesthetized cats of both sexes was given digoxin elixir orally at therapeutic amounts (0.011 mg/kg) once a day for 4 consecutive days. The cumulative effect of digoxin resulted in 62% increase in the mean peak plasma concentration and 231% increase in the 24-hour plasma concentration of digoxin over the 4-day period. Male cats had a significantly (P less than 0.05) higher mean plasma digoxin concentration than did the female cats. Significant changes in the ECG were not recorded. A 3rd group of nonanesthetized cats of both sexes was given a single toxic dose (0.11 mg/kg) of digoxin elixir orally. All cats showed clinical signs of digitalis toxicosis (depression, vomiting, salivation, and anorexia) before ECG changes appeared. Alterations in the ECG were minimal; the most important changes were a slight increase in the PQ interval, an elevated ST segment, and decreased heart rate. Plasma concentrations of digoxin at the time of vomition ranged from 4.45 to 12.12 ng/ml with a mean peak plasma value of 7.37 +/- 3.61 ng/ml. The cats were clinically ill for 48 to 96 hours. A plasma digoxin concentration of 2.3 ng/ml was not toxic.

Topics: Animals; Cat Diseases; Cats; Digoxin; Electrocardiography; Female; Male; Tablets; Vomiting