What is the correct definition for absorption of a drug?

Correct Answer: A

Rationale: The correct definition for absorption of a drug is the movement of a drug from the site of administration (e.g., mouth, skin, injection site) into the bloodstream and then to various tissues of the body. This process is a critical step in the pharmacokinetics of a drug, as it determines the rate and extent to which the drug reaches its target site of action. Absorption can be affected by various factors such as the route of administration, drug formulation, and physiological factors of the individual.

Correct Answer: D

Rationale: Patients taking Angiotensin-converting enzyme (ACE) inhibitors should avoid salt substitutes, foods high in potassium, and foods high in sodium. Salt substitutes often contain potassium chloride, which may cause an increase in potassium levels when combined with ACE inhibitors. Foods high in potassium, such as bananas, oranges, spinach, and potatoes, can also potentially elevate potassium levels when consumed in large amounts. Additionally, foods high in sodium can counteract the effects of ACE inhibitors in managing blood pressure. Therefore, it is important for patients on ACE inhibitors to be mindful of their intake of salt substitutes, high-potassium foods, and high-sodium foods to ensure the effectiveness of their medication and to prevent any potential complications.

Correct Answer: A

Rationale: Digoxin is commonly used to treat atrial flutter and atrial fibrillation by helping to control the heart rate. A loading dose may be given initially to reach therapeutic levels quickly. This medication acts by increasing the force of the heart's contractions and slowing down the heart rate. Propranolol (Choice B) is a beta-blocker used to treat various heart conditions, but it is not typically used for atrial arrhythmias like atrial flutter. Ibuprofen (Choice C) is a nonsteroidal anti-inflammatory drug used for pain and inflammation, not for cardiac arrhythmias. Lithium (Choice D) is a mood-stabilizing medication often used for bipolar disorder and is not indicated for atrial flutter treatment.

Correct Answer: C

Rationale: Thromboxane is a vasoconstrictor that is released by platelets during the process of blood clotting. Local vasoconstriction is a temporary response that occurs to reduce bleeding at the site of injury. Thromboxane plays a role in this process by constricting the blood vessels temporarily to limit blood flow to the injured area. By prolonging the application of thromboxane, vasoconstriction can be prolonged to support the clotting process and minimize bleeding. Adrenaline, steroids, heparin, and thrombin do not have the same vasoconstrictive properties as thromboxane.

Correct Answer: B

Rationale: The first pass effect refers to the metabolism of a drug occurring as it passes from the gastrointestinal tract (GUT lumen) to the liver, before reaching the systemic circulation. This process can significantly reduce the amount of active drug that enters systemic circulation, impacting the drug's overall effectiveness. The first pass effect is an important consideration in pharmacokinetics as it affects the bioavailability of a drug and influences dosing regimens. Options A, C, D, and E do not specifically pertain to the metabolism of a drug en route from the GUT lumen to the systemic circulation as described in the question.