Merlin, also known as ibuprofen suspension, can be used no more than four times in 24 hours, which means that it can be used for the fourth time in 24 hours, but not more times. Ibuprofen suspension is an antipyretic and analgesic drug, which is mainly used to relieve fever caused by common cold or influenza, and can also be used to relieve mild to moderate pain, such as headache, joint pain, migraine, toothache, muscle pain and neuralgia. The effect of this drug usually lasts for 4-6 hours, so if the patient has persistent pain or fever, it can be repeated 4-6 hours apart, but not more than four times in 24 hours, which means that Merlin can be used up to four times every 24 hours. In short, Merlin is an antipyretic and analgesic drug, it is a symptomatic treatment, generally speaking, patients are not recommended to use it for a long time or in large doses, for no more than five days for pain relief, no more than three days for fever relief, and no more than four times a day. Patients must follow the instructions of the drug or the dosage and usage recommended by the doctor when using it.