A nurse is caring for a client who is receiving warfarin (Coumadin) therapy to prevent a deep vein thrombosis.
Which of the following medications should the nurse have available in the event of an overdose?

Choice A rationale

Dysuria, or painful urination, is a common symptom in benign prostatic hyperplasia (BPH) due to the mechanical compression of the urethra by the enlarged prostate, which increases resistance to urine flow. This obstruction leads to bladder overdistention and subsequent irritation, often causing a burning sensation upon voiding as the bladder muscles strain against the increased outflow resistance.

Choice B rationale

Polyuria, characterized by abnormally frequent urination, especially at night (nocturia), is a hallmark of BPH resulting from bladder irritation and incomplete emptying. The residual urine reduces the functional bladder capacity, leading to more frequent urges to void, as the detrusor muscle senses distension at lower volumes, especially during periods of decreased fluid reabsorption at night.

Choice C rationale

While benign prostatic hyperplasia causes an increase in the total amount of prostate-specific antigen (PSA) produced, the levels are usually only mildly to moderately elevated (often <4 ng/mL, though up to 10 ng/mL is possible). Critically elevated PSA levels (e.g., >10 ng/mL or a very high rate of rise) are more suggestive of prostate cancer, not typically benign BPH, which involves non-malignant tissue proliferation.

Choice D rationale

Difficulty starting the flow of urine (hesitancy) is a classic lower urinary tract symptom (LUTS) in BPH caused by the mechanical narrowing of the prostatic urethra. The bladder detrusor muscle must generate significantly increased pressure to overcome this outflow obstruction, resulting in a delay between the sensation of needing to void and the actual initiation of the urine stream.

Choice A rationale

Enoxaparin (a low-molecular-weight heparin) and warfarin (a vitamin K antagonist) are anticoagulants that prevent the formation of new fibrin clots or the enlargement of existing ones, but they do not dissolve established clots; that is the function of thrombolytic agents like tissue plasminogen activator. Administering both aims for adequate anticoagulation until warfarin is fully effective. The correct response emphasizes discontinuing enoxaparin when warfarin is therapeutic.

Choice B rationale

Warfarin, an oral anticoagulant, inhibits vitamin K-dependent clotting factors (II, VII, IX, X), requiring several days to reach a therapeutic effect, which is monitored by the International Normalized Ratio (INR) (therapeutic range typically 2.0–3.0). Enoxaparin, an injectable anticoagulant with immediate onset, is continued concurrently to maintain protection until the INR is therapeutic and adequate anticoagulation is achieved via warfarin alone, a process called bridging.

Choice C rationale

Enoxaparin and warfarin have distinct mechanisms of action and do not enhance each other's effects synergistically; rather, they inhibit different points in the coagulation cascade. Enoxaparin mainly inhibits Factor Xa, while warfarin inhibits Vitamin K-dependent clotting factor synthesis. They are used together to provide immediate anticoagulation (enoxaparin) while awaiting warfarin's delayed onset.

Choice D rationale

While patient education is crucial, responding by deferring the client's question is not therapeutic and does not address the client's need for understanding their therapy. The nurse should explain the rationale for concurrent therapy (bridging) and the planned discontinuation of the injectable drug once the oral medication is within its therapeutic range.