Most of the non- catecholamines function by releasing the physiologic catecholamines from the postganglionic nerve endings
EPHEDRINE
Pharmacokinetics
Ephedrine in absorbed from the gastrointestinal tract and from all parenteral sites. It has a good distribution through out the body and is resistant to hydrolysis by the liver enzymes. Major proportion of the drug is excreted unchanged in the urine. Because of its stability to metabolism it has long duration of action than the catecholamines.
Pharmacodynamics
Ephedrine stimulates both a and b receptors. This effect is partly by a direct action on the receptors and partly indirectly by releasing noradrenaline from its tissue stores the effect of the drug to various organs and systems is similar to that of adrenaline. It is also a mild CNS stimulant.
Indications:
- Bronchial asthma: – usually as a prophylactic for prevention of attacks
- Nasal decongestion
- Mydriasis
- Heart block
- Nocturnal enuresis
Side effects
The side effects are similar to those of adrenaline; but in addition it may produce insomnia and retention of urine.
Contraindications
They are the same as Adrenaline.
Based on their selectivity to specific receptors the rest of the catecholamines, are classified but it is very difficult to exhaust all the drugs. More over their effect and pharmacology is discussed where they are clinically indicated.
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