What is an abacavir HSR?
Abacavir is associated with a risk for hypersensitivity reactions (HSR) characterised by fever and/or rash with other symptoms indicating multi-organ involvement.
An abacavir hypersensitivity reaction (HSR) is an idiosyncratic reaction.
The approximate reporting rate of abacavir HSR in clinical trials was:
- 1% in trials that excluded subjects testing positive for the HLA-B*5701 allele.1
- 5% in trials where HLA-B*5701 screening was not performed.2
Abacavir HSR is clinically well characterised:3
The signs and symptoms of Abacavir HSR have been identified either from clinical studies or post marketing surveillance. Those reported in at least 10% of patients with a hypersensitivity reaction are in bold text.
Almost all patients developing hypersensitivity reactions will have fever and/or rash (usually maculopapular or urticarial) as part of the syndrome, however reactions have occurred without rash or fever. Other key symptoms include gastrointestinal, respiratory or constitutional symptoms such as lethargy and malaise.
Symptoms related to this HSR worsen with continued therapy and can be life- threatening and in rare instance, have been fatal.