The primary causes of duodenal ulcers include:

Choice A reason:
Sucralfate does not primarily work by reducing acid production but rather by forming a protective barrier over ulcers. The statement "Sucralfate reduces acid production in the stomach" is incorrect. Sucralfate's main action is to adhere to the ulcer site and protect it, thus helping in the healing process. The student’s misunderstanding is that sucralfate reduces acid production, which is not the primary mechanism of action for this medication.

Choice B reason:
Sucralfate is known for having minimal systemic side effects because it works locally in the stomach rather than being absorbed into the bloodstream. The statement that sucralfate does not cause systemic side effects is correct, as sucralfate's action is mainly localized to the gastrointestinal tract, making systemic side effects uncommon.

Choice C reason:
Sucralfate should indeed be administered one hour before meals. This timing allows it to form a protective barrier on the stomach lining before food can stimulate acid production, which is crucial for its effectiveness in treating peptic ulcers. Therefore, the statement about its administration time is correct and does not indicate a need for further teaching.

Choice A reason:
The onset of warfarin is delayed, meaning it takes longer to achieve a therapeutic effect. Warfarin requires several days to adjust to effective anticoagulation levels because it works by inhibiting the synthesis of clotting factors that are already present and active in the bloodstream. In contrast, heparin has an immediate anticoagulant effect when administered, which is crucial for patients with acute conditions like deep vein thrombosis.

Choice B reason:
Warfarin does not prevent platelet aggregation. Instead, it works by inhibiting vitamin K-dependent clotting factors, which are essential for blood coagulation. Platelet aggregation is primarily inhibited by antiplatelet drugs like aspirin or clopidogrel, not anticoagulants like warfarin.

Choice C reason:
Heparin does not necessarily have fewer adverse effects compared to warfarin. Both anticoagulants have their specific risks and side effects. Heparin is preferred in acute settings due to its rapid onset of action, but it can cause complications like heparin-induced thrombocytopenia (HIT), which requires careful monitoring.

Choice D reason:
Heparin does not have a longer half-life than warfarin. In fact, heparin's half-life is relatively short, which is why it is often administered via continuous infusion or frequent subcutaneous injections. Warfarin has a longer half-life, but its delayed onset of action makes it less suitable for immediate anticoagulation needs.