A nurse is preparing to administer diphenhydramine to a client who is to receive a blood transfusion. The nurse should explain that the purpose diphenhydramine is to prevent which of the following manifestations of a transfusion reaction?

A) Stool softener:
Stool softeners, such as docusate sodium, work by adding moisture to the stool, making it softer and easier to pass. They do not directly stimulate bowel movements or peristalsis through irritation of the bowel lining.

B) Saline/osmotic laxative:
Saline or osmotic laxatives, such as magnesium hydroxide (milk of magnesia) and polyethylene glycol (PEG), work by drawing water into the intestines, which softens the stool and increases bowel motility. They do not primarily act by irritating the bowel lining.

C) Stimulant laxative.
Stimulant laxatives work by directly stimulating the nerves in the intestines, which increases the rhythmic contractions of the intestines (peristalsis) and promotes bowel movements. These medications irritate the bowel lining, leading to increased motility and expulsion of stool. Examples of stimulant laxatives include bisacodyl and senna.

D) Bulk-forming laxative:
Bulk-forming laxatives, such as psyllium and methylcellulose, work by increasing the bulk and water content of the stool, which stimulates bowel movements. They do not directly irritate the bowel lining to promote peristalsis. Instead, they absorb water and swell in the intestines, creating a larger, softer stool that is easier to pass.

A. Diabetes: Diabetes is not typically a contraindication for decongestant use. However, patients with diabetes should be cautious with decongestants that contain sugar or other ingredients that may affect blood glucose levels.

B. Hypertension: Decongestants can cause vasoconstriction, which may lead to an increase in blood pressure. Patients with hypertension should use decongestants cautiously and under the guidance of a healthcare provider to avoid exacerbating their condition.
C. Hyperthyroidism: While decongestants can stimulate the sympathetic nervous system and may exacerbate symptoms of hyperthyroidism such as tachycardia and palpitations, hyperthyroidism is not typically considered a contraindication for decongestant use. However, patients with hyperthyroidism should use decongestants cautiously and consult with their healthcare provider.

D. Heart disease: Decongestants can increase heart rate and blood pressure, potentially exacerbating symptoms in patients with underlying heart conditions such as coronary artery disease, heart failure, or arrhythmias. Patients with heart disease should use decongestants cautiously and consult with their healthcare provider before use.

E. Allergic rhinitis: Allergic rhinitis is not typically a contraindication for decongestant use. In fact, decongestants are often used to relieve nasal congestion associated with allergic rhinitis. However, patients with allergic rhinitis should use decongestants cautiously and follow the recommended dosage instructions.