Question

Consider the following:

Here are the data for two pain relieving drugs used to manage severe postoperative pain. Both are able to relieve pain completely, provided the proper dose is given.

o Drug A: ED50 = 10 mg // LD50 = 500mg

o Drug B : ED50 = 1 mg // LD50 = 20mg

§ Which drug is most efficacious?

§ Which drug is the most potent?

§ Which has the greatest therapeutic index?

§ Which is safer to administer?

§ Which causes the fewest side effects?

Answer 1

ED 50 means effective dose for 50%of the population..

LD 50 means median lethal dose level 50%..

Oral LD 50 of drug is 229.2mg/kg and ED50 is 0.0125_1mg/kg..

Which drug is most efficacious?

Drug B:ED 50=1mg//LD50=20mg doses are effective and safe..

ED50=10mg//LD50=500mg has toxic effects..

ED50 =1mg//LD50=20mg has less toxic effects and mortality...where the mortality and toxic manifestation increases with the increase in concentration.. analgesic activity more at 1mg/kg..

Drug B has Therapeutic index(TI) is used for low doses may be effective with out producing toxicity..but most patients are preferred for highest dose for fast relief..but it has more toxicity when we use drug A..

Drug B safer to administer.20mg/kg would considered the minimal effective dose and would be the lowest dose recommended on product label..As a general rule,the larger Therapeutic to index,the less toxic the substance, traumatic reaction cannot be predicted for any particular individual due to the existence of idiosyncratic biological factors like person's health status or metabolic anomalies..

Drug B causes fewest side effects like drowsy,dizzy, light-headed, stomach upset...