A college student with migraine headaches that cause nausea and vomiting has been prescribed trimethobenzamide.
The nurse should caution the student to avoid using which substance?

This statement indicates that the patient understands the common side effect of codeine and how to prevent accidents while taking it.

Choice A is wrong because the patient should not take the medication anytime he starts to cough, but only as prescribed by the doctor.

Taking too much codeine can lead to overdose, addiction, or respiratory depression.

Choice B is wrong because this medication may not make the patient anxious and nervous, but rather sedated and relaxed.

Anxiety and nervousness are more likely to occur with decongestants, which are stimulants.

Choice D is wrong because diarrhea is not a common side effect of codeine.

In fact, codeine may cause constipation, so the patient should increase fluid and fiber intake while taking it.

Oxygen cannot diffuse rapidly across the membrane to tissues in the eye. Diabetic retinopathy is caused by damage to the blood vessels of the retina, which is the light-sensitive tissue at the back of the eye. This damage can reduce the oxygen supply to the retina and lead to vision problems.

Choice A is wrong because cells in the eye can reproduce normally, but they may not function properly due to high blood sugar levels or lack of oxygen.

Choice B is wrong because diabetic retinopathy does not affect the production of aqueous humor, which is the fluid that fills the front part of the eye.

However, diabetes can cause another eye condition called glaucoma, which is caused by increased pressure from too much aqueous humor.

Choice C is wrong because diabetic retinopathy does not affect the nerve innervations throughout the eye.

However, diabetes can cause another eye condition called diabetic neuropathy, which is caused by damage to the nerves that control eye movement and pupil dilation.