The invention concerns combinations of alpha adrenergic agents such as brimonidine and its derivatives as represented by formula (I) below wherein each Y is independently selected from the group consisting of N, N—CH3, O, S and C—R1; R1 is hydrogen, lower alkyl or oxo; R2, R3 and R4 are independently selected from the group consisting of hydrogen, halogen, lower alkyl and lower alkenyl; n is an integer from 1 to 3; and a broken line beside a solid line indicates either a single or a double bond with the proviso that when n=1, both bonds from Y to C—R1 cannot be double bonds, and prostaglandins known in the art to cause lowering of intraocular pressure which are useful in compositions, methods of treatment and articles of manufacture for the treatment of glaucoma and alleviation of elevated intraocular pressure and providing neuroprotection.