Author Question: Although heroin and morphine both exhibit analgesic properties, heroin is more potent that morphine ... (Read 108 times)

jparksx · **on:** Jun 22, 2018

Although heroin and morphine both exhibit analgesic properties, heroin is more potent that morphine when injected intravenously. What is the clinical relevance of this difference in potency between these two drugs?

What will be an ideal response?

Question 2

What is the distinction between a drug's clinical efficacy and its potency?

What will be an ideal response?

Alyson.hiatt@yahoo.com · **Reply #1 on:** Jun 22, 2018

Answer to Question 1

While heroin may require much lower doses than morphine to reduce pain, the maximal analgesia that can be achieved with the two drugs is equivalent and their clinical profile (e.g., side-effects) is virtually identical. Unless a more potent drug is capable of inducing a greater maximal response than a lower potency drug, or induces a lower incidence (or different spectrum) of side-effects, or induces benefits more quickly, differences in drug potency are generally not clinically relevant.

Answer to Question 2

Clinical efficacy refers to the degree to which a drug induces clinical benefits, e.g., the proportion of patients responding, the degree of response, the time it takes to respond, etc. Potency refers to the relative degree to which a drug produces a specific type of effect and the magnitude of the effect. The lower the dose necessary to produce that effect or magnitude of effect, the more potent the drug. (For example, clozapine Clozaril is considerably less potent than haloperidol Haldol, because it requires considerably higher doses to control the symptoms of schizophrenia, but it has a greater clinical efficacy because it is more effective in reducing some of the core symptoms of the disease, is effective in a higher percentage of schizophrenic patients, and induces fewer of the types of side effects that lead to noncompliance with treatment.)