Ibuprofen is an antipyretic drug, which belongs to the non-steroidal anti-inflammatory class. When taken at the time of fever, ibuprofen is usually able to reduce the fever in about 1-2 hours. Ibuprofen is available in oral tablets and liquid formulations. As long as the dosage is correct and the patient’s condition is suitable, the fever may be reduced relatively quickly in about an hour after taking ibuprofen, but if the fever does not go down at this time, there is no need to be too anxious, you can wait for another hour, some people will be able to reduce the fever in about two hours. If ibuprofen does not bring down the fever, it is possible that the amount taken is not enough, so you can look at the weight and read the specific instructions of ibuprofen to determine if the amount is enough. If the fever does not go down with enough, then it is likely that the disease in question is more serious, so you can also see no fever going down at this time. If the fever does not go down, you should think of other ways to control the patient’s body temperature, otherwise the body temperature will remain relatively high and the patient will be very uncomfortable and even dehydrated. A further increase in body temperature may also damage the central nervous system, leading to irreversible damage.