A nurse in a coronary care unit is admitting a client who has had CPR following a cardiac arrest. The client is receiving lidocaine IV at 2 mg/min. When the client asks the nurse why he is receiving that medication, the nurse should explain that it has which of the following actions?

Choice A reason: Atropine is not the correct answer, as it is an anticholinergic medication that is used to treat bradycardia, not warfarin overdose. Atropine has no effect on the INR or the coagulation cascade.

Choice B reason: Epinephrine is not the correct answer, as it is a catecholamine medication that is used to treat anaphylaxis, cardiac arrest, or severe hypotension, not warfarin overdose. Epinephrine has no effect on the INR or the coagulation cascade.

Choice C reason: Vitamin K is the correct answer, as it is the antidote for warfarin overdose. Vitamin K is a fat-soluble vitamin that is essential for the synthesis of clotting factors II, VII, IX, and X. Vitamin K can reverse the effects of warfarin and lower the INR to a therapeutic range.

Choice D reason: Protamine is not the correct answer, as it is the antidote for heparin overdose, not warfarin overdose. Protamine is a protein that binds to and neutralizes heparin, but has no effect on warfarin or the INR.

Choice A reason: Migraines are not a contraindication for propranolol. In fact, propranolol is used as a prophylactic treatment for migraines, as it reduces the frequency and severity of migraine attacks.

Choice B reason: Glaucoma is not a contraindication for propranolol. Propranolol does not affect the intraocular pressure or the drainage of aqueous humor in the eye.

Choice C reason: Asthma is a contraindication for propranolol. Propranolol is a nonselective beta-blocker, which means it blocks both beta-1 and beta-2 receptors in the body. Beta-2 receptors are found in the bronchial smooth muscle, and when they are blocked, they cause bronchoconstriction and increased airway resistance. This can worsen the symptoms of asthma and cause a life-threatening asthma attack.

Choice D reason: Depression is not a contraindication for propranolol. Propranolol does not cause depression, although it may cause some side effects such as fatigue, insomnia, and sexual dysfunction. However, these side effects are usually mild and reversible.