Sympathomimetic drugs are agents which in general mimic responses due to stimulation of sympathetic nerves, like ephedra. “The adrenaline and stress of an adventure are better than a thousand peaceful days.”
Biological Source:- It consists of dried young stem of E. gerardiana, and E. nebrodensis belonging to family Gnetaceae (Ephedraceae) collected in autumn. It contains not less than 1% of total alkaloids calculated as ephedrine.
Cultivation and Collection:- Four species of ephedra are reported in India. For medicinal purposes is cultivated successively in U.S.A., England, Kenya and Australia. Indian species are Ephedra gerardiana and Ephedra major. Ephedra can be cultivated at an altitude of 2500 to 3000 m. Annual rainfall should not exceed 50 cm. It can be propagated by seeds or by layers or divisions of the root stock. Seeds are sown early in the spring at a distance of 5 cm keeping the distance of one metre between two rows. The plants are collected after attaining the age of 4 years for the extraction of alkaloids. During this period, proper irrigation and weeding is necessary.
Organoleptic Characters:- It consists of cylindrical woody stem that is grey or greenish in colour. Nodes, internodes, scaly leaves and terminal buds are present in the stems. The distance between the internodes is 3–4 cm and the nodes bare the scaly leaves. They are bitter in taste.
Chemical Constituents:-
It contains about 1 to 1.5 % of total alkaloids of ephedra calculated as ephedrine. The different alkaloids of ephedra are Ephedrine or I-ephedrine, L-methyl ephedrine, D-methyl iso-ephedrine, D-pseudoephedrine, Norephedrine and Dimethyl ephedrine.
USES:- Ephedra is used for early relief of asthama, in hay-fever and whooping cough. It is a sympathomimetic drug. It is used for the extraction of ephedrine. The action of ephedrine is mare prolonged than that of adrenaline. It has further advantage that it need not be given by injection, but may be administered orally.