Your Other Medicines — During Chemotherapy

No. Stopping medicines for blood pressure, diabetes, or epilepsy without guidance is dangerous in its own right and can cause a crisis during treatment. The aim is not to remove your regular medicines but to make sure the combination is safe. Never stop or change a regular medicine without speaking to the doctor who prescribed it. Tell your oncologist what you take and let both doctors decide together.

Both, and that is exactly the gap that causes problems. Your oncologist is responsible for the chemotherapy regimen. Your regular doctor — GP, diabetologist, or cardiologist — is responsible for your chronic medicines. Neither can check the combination unless they both know what the other has prescribed. You are the link between them. Bring the full list to your oncologist and tell your regular doctor which chemotherapy you have started.

Rifampicin is one of the medicines most likely to interact with chemotherapy. It stimulates liver enzymes that process many drugs, which can reduce the amount of chemotherapy active in your body. If you are being treated for TB at the same time as cancer, your oncologist and your TB doctor need to speak to each other directly. Do not assume the combination is safe without that conversation happening.

Some do. Herbal and Ayurvedic preparations are processed by the same liver pathways as many chemotherapy drugs, and some affect those pathways significantly. Most patients do not mention them, and most doctors do not ask. Tell your oncologist everything you take that is not prescribed — herbs, tonics, supplements, and anything you buy without a prescription. You will not be judged for taking them, but your oncologist needs to know.

Yes, at your next appointment. Any medicine prescribed during chemotherapy — for an unrelated condition, a new symptom, or a routine review — needs to be on your oncologist's list. Do not wait until the end of treatment to mention it. If the new medicine was prescribed as something to start immediately, contact your oncology team the same day if possible.

A hospital pharmacist is trained to check for interactions and is a useful extra safeguard. In practice, they can only see what is on the hospital prescription — not medicines prescribed elsewhere or bought without a prescription. The full review requires all medicines to be visible to someone, which means bringing a complete written list to your oncologist. The pharmacist adds a layer; they cannot replace that conversation.

Yes. Chemotherapy and the steroids often given alongside it can raise blood sugar, sometimes significantly. A regimen that was well controlled before treatment may not stay controlled during it. Your oncologist and the doctor managing your diabetes both need to know you are starting chemotherapy so they can agree on what monitoring is needed. Good control before starting does not mean no review is required.

It depends on the type of interaction. Some reduce how much chemotherapy remains active in your body, which can affect whether the treatment works. Others increase chemotherapy levels, raising the risk of side effects. Some affect your regular medicine rather than the chemotherapy — making it less effective or causing unexpected effects. These outcomes are much easier to prevent than to manage after the fact, which is why the review needs to happen before treatment starts.