For better drug efficacy and to reduce adverse drug reactions, it is recommended that different oral chemotherapy drugs be used at different times, such as capecitabine and Tegeo, which are recommended to be taken half an hour after a meal. One common adverse effect of temozolomide is vomiting after administration. To reduce the incidence of adverse reactions, patients are advised to use temozolomide on an empty stomach or at bedtime, the time of fasting being one hour before or more than two hours after meals, so that patients will effectively reduce the incidence of vomiting when using it. There are also drugs that have little effect on efficacy and adverse effects, for example, topotecan does not explicitly require patients to take it before or after a meal. In summary, different oral chemotherapy drugs have different requirements for timing of administration, so patients are advised to consult their pharmacist or competent doctor before using oral chemotherapy drugs to clarify the best timing for drug use.