A nurse is teaching a client who takes warfarin daily. Which of the following statements by the client indicates a need for further teaching?

The correct answer is: d. The client uses garlic to lower cholesterol levels.

Choice A: The client follows a low-fat diet to reduce cholesterol

Following a low-fat diet to reduce cholesterol does not have a significant impact on the effects of warfarin. While diet can influence overall health and cholesterol levels, it does not directly interact with warfarin’s anticoagulant properties.

Choice B: The client drinks a glass of grapefruit juice every day

Grapefruit juice is known to interact with various medications by inhibiting the cytochrome P450 enzymes, particularly CYP3A4. However, grapefruit juice does not significantly affect warfarin metabolism. It is more commonly associated with interactions with statins and other medications.

Choice C: The client sprinkles flax seeds on food 1 hr before taking the anticoagulant

Flax seeds are rich in omega-3 fatty acids and fiber, which can be beneficial for heart health. However, there is no strong evidence to suggest that flax seeds significantly potentiate the effects of warfarin. They do not have a direct interaction with the anticoagulant properties of warfarin.

Choice D: The client uses garlic to lower cholesterol levels

Garlic is known to have antiplatelet properties, which can enhance the anticoagulant effects of warfarin. This can increase the risk of bleeding in clients taking warfarin. Garlic can interfere with the blood clotting process, making it a significant factor to consider when managing a client on warfarin.

Choice A reason: A headache is not likely due to the anxiety about the chest pain, as anxiety usually causes other symptoms, such as palpitations, sweating, or trembling. A headache is more likely related to the vasodilating action of nitroglycerin, which causes increased blood flow to the brain.

Choice B reason: A headache does not indicate tolerance to the medication, as tolerance usually manifests as a reduced effect of the medication on relieving chest pain. A headache is more likely a sign of the medication's potency, as it indicates that the nitroglycerin is reaching the systemic circulation.

Choice C reason: A headache is an expected adverse effect of the medication, as nitroglycerin causes vasodilation of the cerebral vessels, which can result in increased intracranial pressure and pain. A headache is usually mild and transient, and can be relieved by taking analgesics, such as acetaminophen.

Choice D reason: A headache is not an indication of an allergy to the medication, as an allergic reaction usually causes other symptoms, such as rash, itching, swelling, or difficulty breathing. A headache is more likely a pharmacological effect of the medication, rather than an immunological response.