A nurse is reviewing the list of current medications for a client who is to start a new prescription for carbamazepine.
The nurse should identify which of the following medications interacts with carbamazepine?

The client has a negative sputum culture. This indicates that the client is adhering to the medication regimen because a negative sputum culture means that the client is no longer infectious and has cleared the tuberculosis bacteria from their lungs.

Choice A is wrong because testing negative for HIV does not indicate that the client is adhering to the medication regimen for tuberculosis. HIV testing is not related to tuberculosis treatment.

Choice C is wrong because having a positive purified protein derivative test does not indicate that the client is adhering to the medication regimen for tuberculosis.

A positive PPD test means that the client has been exposed to tuberculosis, but it does not indicate whether the client has an active or latent infection. Choice D is wrong because having liver function test results within the expected reference range does not indicate that the client is adhering to the medication regimen for tuberculosis.

Liver function tests are used to monitor for possible adverse effects of isoniazid and rifampin, which can cause hepatotoxicity, but they do not reflect the effectiveness of the treatment.

Furosemide is a diuretic that is used to treat heart failure by reducing fluid retention and lowering blood pressure. It can cause some side effects, such as increased urination, thirst, dry mouth, headache, dizziness, nausea, and electrolyte imbalance.

Choice A is wrong because BUN (blood urea nitrogen) is a measure of kidney function and a normal range is 7 to 20 mg/dL.

A BUN of 15 mg/dL is not a cause for concern and does not indicate any adverse effect of furosemide.

Choice C is wrong because potassium is an electrolyte that is important for nerve and muscle function and a normal range is 3.5 to 5.0 mEq/L.

Potassium of 3.8 mEq/L is within the normal range and does not indicate any adverse effect of furosemide. However, furosemide can cause low potassium levels (hypokalemia) in some cases, so the nurse should monitor the client’s potassium levels regularly and advise the client to eat foods rich in potassium, such as bananas, oranges, and potatoes.

Choice D is wrong because dizziness upon standing is a common side effect of furosemide and does not require immediate notification of the provider. However, the nurse should instruct the client to rise slowly from a sitting or lying position to prevent falls and to drink enough fluids to prevent dehydration.

Choice B is correct because difficulty hearing or hearing loss is a rare but serious side effect of furosemide that may indicate ototoxicity (damage to the inner ear). This can be irreversible if not treated promptly and may affect the client’s quality of life and safety. The nurse should notify the provider immediately if the client reports difficulty hearing or any other signs of ototoxicity, such as ringing in the ears (tinnitus) or vertigo (a sensation of spinning). The provider may need to adjust the dose of furosemide or switch to another diuretic that is less ototoxic.