Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Not all damage to the brain occurs at the moment of injury. The injury sustained at the moment of impact (primary brain injury) initiates a sequence of mechanisms which cause further brain damage (secondary brain injury).
One consequence of the mechanisms triggered by primary injury is the accumulation of fluid within the brain. This condition is known as cerebral oedema and leads to raised intracranial pressure (pressure within the skull), which contributes to secondary brain injury.
The use of a group of drugs known as bradykinin beta-2 receptor antagonists is being investigated as a potential treatment for TBI. It is proposed that they can inhibit the mechanism which causes cerebral oedema and therefore prevent the elevation of intracranial pressure with subsequent brain damage.
The authors of this review searched for all randomised controlled trials investigating the effects of bradykinin beta-2 receptor antagonists in traumatically brain injured patients. The authors found four trials involving 406 patients. Whilst the overall effect estimates suggest that bradykinin beta-2 receptor antagonists may reduce mortality and disability, they also suggest that they may increase the number of serious adverse events. However, all of these results are consistent with the play of chance. The findings indicate that there is no evidence to support the use of bradykinin beta-2 receptor antagonists for TBI.
Bradykinin beta-2 receptor antagonists are not presently registered for use in patients. Because the safety and effectiveness of bradykinin beta-2 receptor antagonists have not been reliably ascertained, they should not be used outside the context of well conducted trials.