Table 2. Types of anti-oestrogen therapy
TherapyMechanismExamples
Aromatase inhibitorBlocks the enzymatic activity of aromatase and inhibits 17β-oestradiol (E2) synthesisLetrozole, anastrozole, exemestane
Oestrogen receptor downregulatorBinds directly to oestrogen receptors and thus inhibits oestrogen binding
Reduces number of oestrogen receptors
Alters the shape or conformation of oestrogen receptors
Fulvestrant
Selective oestrogen receptor modulatorSelectively binds to oestrogen receptors and thus inhibits oestrogen bindingTamoxifen, raloxifene, toremifene