What does a higher therapeutic index indicate about a drug?

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Multiple Choice

What does a higher therapeutic index indicate about a drug?

The therapeutic index shows the safety margin between the dose that produces the desired effect and the dose that causes toxicity. A higher ratio means toxic (or lethal) doses are much farther away from the effective dose, so the drug is safer to use across different patients and dosing situations. In practice it’s calculated as TD50 (or LD50) divided by ED50, not the other way around, so saying it’s the ratio of therapeutic dose to toxic dose is incorrect. It also doesn’t tell you how quickly a drug acts, and it isn’t a concept limited to vaccines. So a higher TI indeed indicates greater drug safety.

The therapeutic index shows the safety margin between the dose that produces the desired effect and the dose that causes toxicity. A higher ratio means toxic (or lethal) doses are much farther away from the effective dose, so the drug is safer to use across different patients and dosing situations. In practice it’s calculated as TD50 (or LD50) divided by ED50, not the other way around, so saying it’s the ratio of therapeutic dose to toxic dose is incorrect. It also doesn’t tell you how quickly a drug acts, and it isn’t a concept limited to vaccines. So a higher TI indeed indicates greater drug safety.

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