Fever is a phylogenetically ancient host reaction to invading microorganisms and other noxious stimuli. Poikylothermic organisms can reach febrile temperatures by seeking a hot environment in response to a higher set point in their thermoregulatory center. Endothermic organisms produce febrile temperatures through endogenous heat production at the expenditure of a higher metabolic rate. Nevertheless,
fever has been conserved during evolution through millennia, obviously because of its advantage for host defense. Despite of these arguments most doctors, nurses and patients treat
fever with
antipyretics. The role of
fever for the recovery from low risk
infections is marginal at best. A large study of
ibuprofen in patients with
severe sepsis could not establish a positive or negative role on the course or final outcome of the
infection in an
intensive care setting. These clinical observations seemingly contradict findings in severe experimental
bacterial infections in rodents but it has to be taken into consideration that these animals, in contrast to patients, received no
antibiotic treatment. In patients with
influenza-like illnesses non-steroidal antirhumatics (NSAR) improve
fever and wellbeing with little or no evidence for undesired side-effects. It therefore appears appropriate to treat patients with these and similar
infections with NSAR.
Antipyretic therapy in special patient groups such as
brain injury victims, patients with cardiac or
respiratory failure or
dementia has not been established to be indicated to overcome a worsening of these organs to fail during
infections. In children with a history of
fever convulsions prevention or lowering of
fever does not reduce recurrence. In patients with
strokes it appears advisable however to use
antipyretics in case of
fever despite of a present lack of a proven beneficial effect. In conclusion symptomatic
antipyretic therapy should be considered for low risk
infections if patient suffering from
fever. For more severe
infections antipyretic therapy can be applied on an individual basis without too much hope to improve outcome or cause a severe worsening of prognosis.