WBR0442
| Author | [[PageAuthor::Rim Halaby, M.D. [1] (Reviewed by Alison Leibowitz)]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pharmacology |
| Sub Category | SubCategory::Cardiology |
| Prompt | [[Prompt::A researcher, assessing difference between the intravenous (i.v.) and the oral forms of metoprolol using mice, administers both drugs to the mice and notes the following plasma concentrations of the medications illustrated in the graph below. Which of the following equations best corresponds to the bioavailability (F) of 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::This equation is not used to calculate bioavailability. |
| Answer C | AnswerC::(AUCi.v. / AUCoral) x (Doseoral x Dosei.v.) |
| Answer C Explanation | AnswerCExp::This equation is not used to calculate bioavailability. |
| Answer D | AnswerD::(Doseoral x AUCoral) x (Dosei.v. x AUCi.v.) |
| Answer D Explanation | AnswerDExp::This equation is not used to calculate bioavailability. |
| Answer E | AnswerE::(AUCoral + Doseoral) / (AUCi.v. + Dosei.v.) |
| Answer E Explanation | AnswerEExp::This equation is not used to calculate 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 can be calculated with the following equation: F = (AUCoral / AUCi.v.) x (Dosei.v./Doseoral) |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Bioavailability, WBRKeyword::pharmacokinetics, WBRKeyword::pharmacodynamics, WBRKeyword::oral, WBRKeyword::intravenous, WBRKeyword::equation, WBRKeyword::formula, WBRKeyword::calculation |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |
