Merrill is ibuprofen suspension, Tylenol is acetaminophen suspension, if the fever does not go down, it may be that the dose is not enough or the cause of the disease has not been removed, and it is necessary to increase the dosage or to treat the cause of the disease. 1. insufficient dose: ibuprofen suspension and acetaminophen suspension are common antipyretic drugs, both by inhibiting the synthesis of prostaglandins to achieve antipyretic and analgesic effect. Ibuprofen suspension and acetaminophen suspension do not reduce the fever of the case first need to check the amount of medicine, whether it is due to insufficient amount of medicine caused by the fever does not go down, if the amount of medicine is insufficient, you need to increase the amount of medicine under the guidance of the doctor. 2. The cause of the disease has not been removed: If the cause of the disease has not been removed, such as intracranial tumors or hemorrhage, infarction caused by central hyperthermia, the cause of the disease has not been removed, the use of antipyretic drugs can not bring down the body temperature. In addition, you can use alcohol to wipe the forehead or use warm water to wipe the body, through the evaporation of water on the surface of the body to take away the heat to cool down, in addition, you can also drink more warm water to cool down the temperature, drink more warm water will lead to sweating and increase the amount of urine, will also take away part of the heat, and then achieve the effect of cooling down the fever. If the fever does not go down for a long time, it is recommended to consult a doctor.