A patient has received an overdose of intravenous heparin, and is showing signs of excessive bleeding. Which substance is the antidote for heparin overdose?

Correct Answer: C

Rationale: Protamine sulfate is the antidote for heparin overdose. Heparin is a commonly used anticoagulant medication that works by inhibiting the activity of thrombin and preventing blood clot formation. In the case of an overdose leading to excessive bleeding, protamine sulfate can be administered to neutralize the effects of heparin. Protamine sulfate forms a complex with heparin, therefore reversing its anticoagulant effects and helping to stop the bleeding. This antidote is especially useful in situations where immediate reversal of heparin's effects is necessary to prevent serious complications.

Correct Answer: C

Rationale: In order to prevent graft-versus-host disease (GVHD) in a severely immunocompromised patient receiving a blood transfusion, the physician will order irradiation of the donor blood. GVHD is a rare but serious complication that can occur when the donor's T lymphocytes attack the recipient's tissues. Irradiation of the blood eliminates the T lymphocytes, thereby reducing the risk of GVHD in immunocompromised patients. Diphenhydramine hydrochloride (Benadryl) and acetaminophen (Tylenol) are commonly used to manage transfusion reactions but do not specifically prevent GVHD. Administering the transfusion slowly over several hours does not directly address the risk of GVHD.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: C

Rationale: Efficacy refers to the maximal response a drug can produce, regardless of the dose. It is a measure of how well a drug can produce its desired effect. Potency, on the other hand, refers to the amount of drug required to produce a specific effect and is not related to the maximal response. An agonist is a drug that binds to and activates a receptor. Bioavailability is the fraction of the administered dose of a drug that reaches the systemic circulation.

Correct Answer: C

Rationale: The correct instruction for the nurse to give the client regarding discontinuing a beta blocker is that it should NOT be abruptly stopped; the dose should be tapered down. Suddenly stopping a beta blocker can lead to rebound hypertension, angina, and even heart attack in some cases. Tapering down the dose helps the body adjust gradually and reduces the risk of adverse effects associated with abrupt discontinuation. It is important for the client to follow the healthcare provider's guidance on how to safely decrease the dose of the beta blocker.