Reserpine gastrointestinal effects

Because of the side effects (psychic depression, gastrointestinal disorders) of reserpine, extended research work has been carried out to find a proper analog or... 

At the low doses usually administered, reserpine produces little postural hypotension. Most of the unwanted effects of reserpine result from actions on the brain or gastrointestinal tract. 

Reserpine Blocks vesicular amine transporter in noradrenergic nerves and depletes transmitter stores Reduce all sympathetic effects, especially cardiovascular, and reduce blood pressure Hypertension but rarely used Oral long duration (days) Toxicity Reserpine psychiatric depression, gastrointestinal disturbances ... 

Pharmacological evaluation of the ethers and their water-soluble salts revealed a marked sedative action in dogs without any demonstrable antihypertensive effect. The tranquilizing activity differs from that of reserpine in that its onset occurs within minutes rather than hours and the duration of action is considerably shorter than that of reserpine. Cumulation is not evident on repeated administration there is no effect on the gastrointestinal tract and no diarrhea occurs (182). Clinically, the normal, as well as the 18-epi, ethers were found to be effective when given to patients with mild or moderate anxiety. However, the tranquilizing activity of the normal ethers is considerably higher, and for all practical purposes the 18-epi ethers are not suitable for human therapy. 

The side-effects of reserpine include hypotension, bradycardia and increased gastrointestinal motility and diarrhea (Lloyd et al 1985), all resulting from decreased sympathetic tone and increased parasympathetic tone. The hypotensive effects of reserpine may take days to several weeks to occur but may persist for 1 to 6 weeks after the withdrawal of the dmg. Administration of induction agents, such as xylazine and ketamine, that produce hypotension may be fatal in horses treated with reserpine. 

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