A preliminary investigation of the therapeutic value of lanatoside C (Digilanid C)

1. 1. Lanatoside C, which is a stable, crystalline glycoside derived from digitalis lanata, caused no anatomic changes in the heart muscle of the dog when it was given in therapeutic doses daily for a period of three months. 2. 2. Lanatoside C, when administered intravenously to patients with auricular fibrillation, reduces the heart rate to normal within a period of two minutes to two hours. When administered orally, lanatoside C reduces the rate of the heart to normal within twenty-four to forty-eight hours. 3. 3. Lanatoside C is efficacious in the treatment of congestive heart failure when normal sinus rhythm is present. In fact, the efficacy of lanatoside C in the presence of normal sinus rhythm is almost as great as when the heart failure is associated with auricular fibrillation. 4. 4. Lanatoside C will often restore normal rhythm in cases of supraventricular paroxysmal tachycardia and auricular flutter. In eight of our 102 cases of nonparoxysmal auricular fibrillation, normal sinus rhythm became established spontaneously during treatment with lanatoside C. 5. 5. Lanatoside C will reduce the pulse rate to normal in some cases of auricular fibrillation associated with hyperthyroidism, and, in at least one case, the venous pressure was brought down from 22 cm. of water to 9 cm. of water within forty-eight hours. 6. 6. Lanatoside C seems definitely less toxic than preparations of digitalis purpurea. Some patients who cannot tolerate digitalis purpurea can take lanatoside C in sufficient doses to aid in the relief of their heart failure.