Merlin needs to be stored under the conditions specified in the instructions, in principle, it can be taken within the validity period after opening, it is recommended to use it within 1-2 months after opening the lid, more than two months is not recommended, so that the safety and effectiveness of use can be guaranteed. The main ingredient of Merlin is ibuprofen suspension drops, the main ingredient is ibuprofen, used for the treatment of fever in infants and children, relief of mild headache, sore throat and toothache caused by cold and flu. If it is not stored under the prescribed storage conditions, and if it is used after the expiration date, safety and effectiveness cannot be guaranteed, so it depends on the expiration date and storage conditions. Before using the medicine, you should also read the instruction manual in detail to understand the dosage and precautions and other information related to the use of the medicine. After using the medicine for a period of time, if the symptoms are not relieved within a short period of time, it is necessary to go to the hospital for consultation. If the child has any discomfort, serious symptoms or other adverse events during the medication period, he/she should stop the medication and go to the hospital in time. Use Merlin with caution if patients with serious cardiac system disease, which may lead to serious cardiovascular thrombosis, for a maximum of 3 days if used for fever relief and no more than 5 days if used for pain relief. If adverse reactions occur while using the drug, prompt medical attention is required.