Convallaria.
The rhizome and rootlets of Convallaria majalis, Linné (Nat. Ord. Liliaceae.)
Common Name: Lily of the Valley.
Principal Constituents.—Two glucosides: convallamarin (C23H44O12), a bitter, crystalline powder, and convallarin (C34H62O11), the acrid principle.
Preparation.—Specific Medicine Convallaria. Dose, 1 to 10 drops.
Specific Indications.—Cardiac irregularities due to mechanical impediments; mitral insufficiency; feeble circulation and low arterial tension; dropsy of cardiac origin; palpitation and vehement heart action, with arrhythmic movements, dyspnea, and diminished arterial pressure; feeble, quickened pulse, with capillary obstruction.
Action and Therapy.—In its effects upon the human circulation convallaria closely resembles that of its more powerful congener, digitalis, without, however, causing the unpleasant disturbances occasioned by that drug. Unlike digitalis it is not cumulative, nor is it distinctly poisonous. Moreover, it has a laxative action, and like digitalis, increases diuresis secondarily, by its effects upon blood pressure.
Like digitalis, convallaria may be used where there is feeble circulation and low blood-pressure. While digitalis is the more often indicated, sometimes convallaria is more effective on account of the disturbing extravascular effects of the former. Convallaria appears to act best in those cases of circulatory failure in which there is imperfect circulation within the heart itself and probably due to capillary resistance or peripheral circulatory enfeeblement. By relieving the latter the cardiac embarrassment is removed. Convallaria slows the pulse and gives increased force to the heart-beat. It undoubtedly tones the heart muscle and strengthens its action. By the double action of augmenting the power of the heart and the tone of the vessels, as well as by its secondary effect of increasing renal activity, it acts extremely well in dropsy of cardiac origin. Palpitation and irregular heart movements, dyspnoea, diminished urinary secretion, albumen, hepatic fullness and engorgement, and edema-symptoms of this form of cardiac insufficiency, gradually disappear under small and continued doses of this drug. Moderate doses calm cardiac excitement, such as is due to overexertion and the excessive use of tobacco. Cardiac arrhythmia and hurried action of the heart are especially benefited by it.
The heart irregularities corrected by convallaria are not those due to organic degeneration, but rather those of an obstructive character, due to mechanical causes, as when the mitral valves are involved. Thus it is especially valuable in mitral insufficiency, with its attendant dyspnea and palpitation. When acting favorably the heart action becomes slower and stronger, normal rhythm is established, arterial pressure increased, respiration deepened, and the sense of suffocation, with the distressing and painful desire for air, is dispelled. A drug that will bring about these results and do it kindly is an ideal heart stimulant, and such is convallaria. Convallaria relieves the sense of praecordial oppression and faintness that so frequently follows prostrating diseases. Not alone is it a heart tonic, but a gastric tonic as well. Therefore it is indicated by the cardiac debility that follows typhoid fever, la grippe, acute articular rheumatism, and other heart-enfeebling diseases. When a heart stimulant is needed during acute rheumatism, convallaria is, as a rule, preferable to digitalis, and it is often valuable in the early stages of rheumatic carditis and endocarditis, using it in fractional doses. Convallaria is of less service in stenosis of the aorta than in mitral disorders.
