A patient who is HIV-positive has been receiving medication therapy that includes zidovudine.

The prescriber has decided to stop the zidovudine due to its dose-limiting adverse effect.

Which of these conditions is the dose-limiting adverse effect of zidovudine therapy?

Choice A rationale:

Confusion can be a symptom of Diabetic Ketoacidosis (DKA). DKA is a serious complication of diabetes that occurs when your body produces high levels of blood acids called ketones. The condition develops when your body can’t produce enough insulin. Insulin normally plays a key role in helping sugar (glucose) — a major source of energy for your muscles and other tissues — enter your cells. Without enough insulin, your body begins to break down fat as fuel. This process produces a buildup of acids in the bloodstream called ketones, eventually leading to diabetic ketoacidosis if untreated.

Choice B rationale:

Polydipsia, or excessive thirst, is another common symptom of DKA. High blood sugar levels can cause increased urination, leading to dehydration and an increased feeling of thirst.

Choice C rationale:

A rapid pulse is also a symptom of DKA. This is because the body is trying to compensate for the low amount of fluid in your blood vessels due to dehydration.

Choice D rationale:

Clammy skin is not typically a symptom of DKA. It’s more commonly associated with hypoglycemia (low blood sugar), not hyperglycemia (high blood sugar) which is what occurs in DKA1.

Choice A rationale:

Zidovudine, also known as AZT, is a medication used for the treatment of human immunodeficiency virus (HIV) infection. One of the major dose-limiting toxic effects of Zidovudine is hematologic toxicity, which manifests clinically as anemia, neutropenia, and sometimes as platelet deficits with onset after several weeks of treatment. This hematologic toxicity is essentially a form of bone marrow suppression. Therefore, bone marrow suppression is the dose-limiting adverse effect of zidovudine therapy.

Choice B rationale:

Retinitis is not a known dose-limiting adverse effect of zidovudine. While zidovudine has a range of side effects, retinitis is not commonly associated with its use.

Choice C rationale:

Renal toxicity is not a known dose-limiting adverse effect of zidovudine. While zidovudine can have various side effects, renal toxicity is not typically one of them.

Choice D rationale:

Hepatotoxicity is not the dose-limiting adverse effect of zidovudine. While severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of zidovudine, it is not considered the dose-limiting adverse effect. The dose-limiting adverse effect is more specifically related to hematologic toxicity, which includes bone marrow suppression.