A histamine antagonist (commonly called an antihistamine) is a pharmaceutical drug that inhibits the action of histamine by either blocking its attachment to histamine receptors, or inhibiting the enzymatic activity of histidine decarboxylase which catalyzes the transformation of histidine into histamine (atypical antihistaminics). Histamine antagonists are commonly used for the relief of allergies caused by intolerance of proteins.
![Aerius 5mg 45 Tablets - $21.95 (Free Click and Collect or $5 Postage) @ Blackshaws Road Pharmacy [VIC]](https://files.ozbargain.com.au/n/27/270227.jpg?h=b1492854)



![[Preston Market, VIC] PharmaSave - Livostin Eye Drops 4ml $6.00 MARKET PRICE (RRP $10.99)](https://files.ozbargain.com.au/n/52/212052.jpg?h=2d6d7653)














