Which drugs act on the sympathetic nervous system, which regulates blood pressure by controlling heart rate, cardiac output, vascular tone, and renin release?

Losartan (Cozaar) is an angiotensin II receptor blocker (ARB) that is used to treat heart failure by lowering blood pressure and reducing fluid retention.

Patients taking losartan should:

• Weigh themselves every morning and report any changes.

This helps to monitor fluid status and detect signs of worsening heart failure.Weight gain of more than 2 kg (4.4 lb) in a week or 1 kg (2.2 lb) in a day should be reported to the health care provider.

• Call their doctor if they have a sore throat or fever.This could indicate an infection or a rare but serious side effect of losartan called angioedema, which causes swelling of the face, lips, tongue, or throat.

The other choices are wrong because:

• Losartan does not need to be taken with food to prevent stomach upset.It can be taken with or without food.

• Losartan does not increase the sensitivity to sunlight.However, some other medications for heart failure, such as diuretics, may do so.

• Drinking plenty of fluids to stay hydrated is not recommended for patients with heart failure, as it may worsen fluid retention and overload the heart.Patients should follow their prescribed fluid restriction and limit their sodium intake.

Warfarin is an anticoagulant that prevents blood clots from forming or growing larger. It works by inhibiting the synthesis of vitamin K-dependent clotting factors in the liver. The INR (international normalized ratio) is a measure of how long it takes the blood to clot.The therapeutic range for INR depends on the indication for warfarin therapy, but for atrial fibrillation, it is usually between 2 and 3. An INR level of 3.5 is above the therapeutic range, which means the blood is too thin and the patient is at risk of bleeding. The nurse should hold the warfarin dose and notify the physician, who may order vitamin K to reverse the effects of warfarin.

Choice A) Administer vitamin K as ordered by physician is wrong because vitamin K is not indicated unless the physician orders it based on the patient’s condition and INR level.

Vitamin K is an antidote for warfarin overdose and can reverse its anticoagulant effects.

However, administering vitamin K without a physician’s order may cause the INR to drop below the therapeutic range and increase the risk of clotting.

Choice B) Administer heparin as ordered by physician is wrong because heparin is another anticoagulant that works by activating antithrombin, a natural inhibitor of clotting factors.

Heparin is used for acute treatment of thromboembolic disorders, such as deep vein thrombosis or pulmonary embolism.

It is not indicated for atrial fibrillation unless there is evidence of acute thrombosis.

Administering heparin to a patient with an elevated INR would increase the risk of bleeding.

Choice C) Administer warfarin as ordered by physician is wrong because warfarin is the cause of the elevated INR and should be withheld until the INR returns to the therapeutic range.

Continuing to administer warfarin would further increase the INR and the risk of bleeding.