During a routine checkup, a patient states that she is unable to take the prescribed antihistamine because of one of its most common adverse effects. The nurse suspects that which adverse effect has been bothering this patient?

Choice A reason: This is incorrect because constipation is not a common or serious adverse effect of antihistamines. However, the patient should increase their fluid and fiber intake and exercise regularly to prevent constipation.

Choice B reason: This is incorrect because abdominal cramps are not a common or serious adverse effect of antihistamines. However, the patient should avoid spicy or fatty foods and take the antihistamine with food or milk to prevent stomach irritation.

Choice C reason: This is correct because drowsiness is one of the most common and bothersome adverse effects of antihistamines. The patient should avoid driving or operating machinery if they experience drowsiness and take the antihistamine at bedtime.

Choice D reason: This is incorrect because decreased libido is not a common or serious adverse effect of antihistamines. However, the patient should inform their provider if they experience any sexual dysfunction or mood changes while taking the antihistamine.

Choice A reason: This is incorrect because hypoxia does not cause an increased need for insulin, but rather a decreased utilization of glucose by the cells. Hypoxia can also impair the secretion of insulin by the pancreas.

Choice B reason: This is correct because corticosteroids are known to cause hyperglycemia by stimulating gluconeogenesis, inhibiting glucose uptake, and increasing insulin resistance. The patient may need to adjust his insulin dose or switch to oral antidiabetic agents while on corticosteroid therapy.

Choice C reason: This is incorrect because antibiotics do not cause an increase in glucose levels, unless they are combined with other drugs that affect glucose metabolism, such as sulfonamides or fluoroquinolones.

Choice D reason: This is incorrect because type 2 diabetes does not convert to type 1 diabetes, as they are different types of diabetes with different causes and mechanisms. Type 1 diabetes is caused by autoimmune destruction of the beta cells of the pancreas, resulting in absolute insulin deficiency. Type 2 diabetes is caused by insulin resistance and relative insulin deficiency.