Unless otherwise specified, the use of tea is not recommended. Tea can reduce the effectiveness of medication or affect its absorption, and in severe cases may even produce toxic side effects. Tea contains theophylline, ellagic acid, tea polyphenols, caffeine and other substances, which can weaken the effectiveness of the drug and have an effect on certain drugs. For example, the theophylline and caffeine in tea will inhibit the sedative drug phenobarbital, resulting in a weakening of the drug’s efficacy. The ellagic acid content may cause precipitation of safranin and ferrous sulfate tablets, hindering the body’s absorption of the drug ingredients. The substances contained in tea may only affect the medicinal properties of the drug when the reaction with the drug is small, but if the reaction is large, it may produce toxic side effects and cause gastrointestinal discomfort, so it is recommended that you do not use tea to take the medication. When taking medication, you should follow the doctor’s instructions and seek immediate medical attention if you experience any discomfort.