Drugs that cause loss of appetite: what to know

Appetite can fall after starting or changing a medicine, especially when it causes nausea, dry mouth, altered taste, constipation, or early fullness. The symptom can also occur with gastroenteritis, influenza, COVID-19, hepatitis A, gastritis, or a peptic ulcer. Low mood can reduce interest in food as well. A clinician will consider the timing, other symptoms, existing conditions, and all medicines rather than blaming one tablet automatically. Children, older adults, and people with long-term illness may become unwell sooner when they eat and drink less.

Record when the appetite change began, what you can tolerate, and any nausea, pain, fever, bowel changes, or altered taste. Take medicines exactly as prescribed and ask a pharmacist whether timing with food is allowed or recommended. Do not stop essential treatment without advice. Small frequent meals, nourishing drinks, and familiar foods may be easier than large portions. Keep drinking fluids, and arrange a review if eating remains difficult or the symptom follows a new medicine.

Seek urgent care for confusion, fainting, severe weakness, severe abdominal pain, repeated vomiting, yellowing of the skin or eyes, or inability to keep fluids down. Prompt assessment is also needed for ongoing appetite loss with marked weight change, persistent fever, blood in vomit or stools, or worsening pain. These features can point to dehydration, infection, digestive disease, or another problem needing treatment.

Ask whether a medicine could explain the change, whether another formulation is possible, and how to protect hydration and nutrition. Ask which symptoms should prompt testing for infection, stomach disease, mood changes, or another cause.