WBR0442
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pharmacology |
| Sub Category | SubCategory::Cardiology |
| Prompt | [[Prompt::A researcher is assessing in an experiment using mice the difference between the intravenous (i.v.) and the oral forms of metoprolol. He administers both drugs into mice and notes the following plasma concentrations of both medications in the graph shown below. Which of the following equations best corresponds to the bioavailability (F) of the metoprolol in the oral form?
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| Answer A | AnswerA::F = (AUCoral / AUCi.v.) x (Dosei.v./Doseoral) |
| Answer A Explanation | AnswerAExp::Bioavailability can be calculated using the equation: F = (AUCoral / AUCi.v.) x (Dosei.v./Doseoral) |
| Answer B | AnswerB::(AUCoral / Doseoral ) x (AUCi.v. x Dosei.v.) |
| Answer B Explanation | AnswerBExp::The equation is not correct to calculate the bioavailability. |
| Answer C | AnswerC::(AUCi.v. / AUCoral) x (Doseoral x Dosei.v.) |
| Answer C Explanation | AnswerCExp::The equation is not correct to calculate the bioavailability. |
| Answer D | AnswerD::(Doseoral x AUCoral) x (Dosei.v. x AUCi.v.) |
| Answer D Explanation | AnswerDExp::The equation is not correct to calculate the bioavailability. |
| Answer E | AnswerE::(AUCoral + Doseoral) / (AUCi.v. + Dosei.v.) |
| Answer E Explanation | AnswerEExp::The equation is not correct to calculate the bioavailability. |
| Right Answer | RightAnswer::A |
| Explanation | [[Explanation::Bioavailability (F) is defined as the proportion of the total area under the plasma concentration-time curve (AUC). The relative bioavailability of the oral form of a drug can be calculated using the following equation: F = (AUCoral / AUCi.v.) x (Dosei.v./Doseoral)
Educational Objective:
Bioavailability = F = (AUCoral / AUCi.v.) x (Dosei.v./Doseoral) |
| Approved | Approved::No |
| Keyword | WBRKeyword::Bioavailability, WBRKeyword::pharmacokinetics, WBRKeyword::pharmacodynamics, WBRKeyword::oral, WBRKeyword::intravenous |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |
