Ephedrine is the active principle of the Chinese drug, Ma Huang (ephedra vulgaris). It was first isolated by Yamanashi, and recently has been studied comprehensively by Chen. Its pharmacologic action is similar to that of epinephrine. It has a stimulating action on the peripheral vasoconstrictors, and is a cardiac accelerant. It differs from epinephrine in being effective whether administered hypodermically or orally, in producing a more sustained effect and in its low toxicity. Miura observed its mydriatic action on the eye, and since Chen's1 study its effects have been observed in many conditions known to be influenced by epinephrine. It has been used as an astringent for mucous membranes, to stimulate circulation and to elevate the blood pressure in Addisons' disease and in other forms of chronic hypotension.
THERAPEUTIC USES OF EPHEDRINE
A number of reports have appeared recently on the effectiveness of ephedrine in asthma, and Miller2
KESTEN BM. TREATMENT OF URTICARIA WITH EPHEDRINE. Arch Derm Syphilol. 1927;16(2):189–195. doi:10.1001/archderm.1927.02380020061008