We report this case to highlight the possibility of a severe hypersensitivity 
reaction as an important potential consequence of couples, living with HIV, 
sharing anti-retroviral treatment. An HIV-1 positive and carrier of HLA-B*57:01 
allele, treatment experienced man was commenced one pill Regimen Stribild 
(tenofovir, emtricitabine, elvitegravir and cobicistat) in July 2015. On running 
short of medication, he admitted to sharing his partner's treatment (Triumeq; 
abacavir, lamivudine and dolutegravir). On the second occasion, re-introduction 
resulted in whole body rash 4 h post dose and was associated with fever, 
respiratory symptoms, headache and vomiting. On examination, he was pyrexic, 
tachyponeic, tachycardiac and hypotensive. Hypersensitivity to abacavir can 
cause significant morbidity. Re-challenge can result in a more rapid, severe and 
potentially life-threatening reaction. This potentially could become an 
increasing problem with more couples, living with HIV, sharing medication.