Skip to Content
Interactive Textbook on Clinical Symptom Research Logo


Home button

Trial Design: Pain Sections
Author Bio
Introduction
Placebo Effects
Single Dose Trials
Repeated Dose Trials
Explanatory Versus Pragmatic
Currently selected section: Dose-Response
Parallel Group Versus Crossover
Conclusion
 

 

Chapter 1: Clinical Trials of Pain Treatment: Dose-Response; Relative Potency; Combinations

 
           

Problem 6.3

An investigator is carrying out a single-dose postoperative assessment to learn the relative potency of a new opioid-like analgesic, Drug R, to morphine. Because of financial constraints, he only tests one dose of each drug—Drug R, 10 mg, and morphine, 7.5 mg, in groups of 50 patients each and gets the following results for analgesia (below, left panel) and for sedation (right panel), the most important clinical side effect of Drug R.

Assume that the standard errors [not shown] were quite small compared to the differences in effects.

Figure 6.3.4:  Drug R, 10 mg, produced significantly more pain relief and significantly more sedation than morphine 7.5 mg.

Question 6.3.1

What can one say about the comparison of the likely usefulness of Drug R and morphine from the above two graphs?

Selection ADrug R probably has a superior therapeutic ratio (that is, ratio of analgesia to sedation) compared to morphine

Selection BDrug R probably has an inferior therapeutic ratio (that is, ratio of analgesia to sedation) compared to morphine.

Selection CDrug R and morphine look about the same in their propensity to relieve pain and cause sedation.

Selection D The data is insufficient to compare the effects of the two drugs.


Page 37 of 52
      Previous Page