Medications and the Digestive System Medications taken by mouth can affect the digestive system in a number of different ways. Both prescription and over-the-counter drugs, while usually safe and effective, may create harmful effects in some people. Taking Your Medication Medicines can be an important part of treatment for serious infections. They can help relieve pain and lift depression. Food-Drug Interactions A food-drug interaction can occur when the food you eat affects the ingredients in a medication you are taking, preventing the medicine from working the way it should. Learning to Manage Multiple Medications The average American takes between two and seven prescription drugs daily. Managing these medications properly is essential for good health. Over-the-Counter Remedies for Seniors It's easy to forget that OTC remedies are drugs that can cause side effects and affect other medications. That's why it's important to read the dosage instructions, health risks and warnings on the packaging. How to Get Medications for Less Here are strategies from the Food and Drug Administration to help you cut your prescription costs by 50 percent or more. OTC Medications: Understanding the Risks Just because over-the-counter medications are readily available doesn’t mean you don’t need to follow an OTC drug’s directions carefully.