PMC:2792620 / 10898-12826
Annnotations
{"target":"http://pubannotation.org/docs/sourcedb/PMC/sourceid/2792620","sourcedb":"PMC","sourceid":"2792620","source_url":"http://www.ncbi.nlm.nih.gov/pmc/2792620","text":"Alpha-2-AGONISTS\n\nClonidine\nClonidine is the first available a-2 agonist, for the treatment of glaucoma. Clonidine is a lipophilic molecule, which is a relatively selective a-2 adrenoceptor agonist with some a-1 adrenoceptor agonistic activity. It crosses the blood brain barrier and causes systemic hypotension.\n\nApraclonidine\nApraclonidine or para aminoclonidine is a derivative a-2 adrenergic agonist. It decrease the aqueous humor secretion and the episcleral venous pressure.[18] It is not recommended as a long-term therapy because of the high incidence of local adverse reactions and tachyphylaxis. It is indicated for short-term use for the prevention or control of post-surgical increases in IOP, and indicated as an adjunctive agent for POAG. Long-term therapy with apraclonidine causes allergic blepharoconjuctivitis.[19] The mean reductions in IOP range from 20% to 27%.[20] Apraclonidine is available as 0.5 and 1% concentrations, to be applied twice daily.\n\nBrimonidine\nBrimonidine is the a-2 agonist of choice in glaucoma treatment, which acts by decreasing the aqueous humor secretion and increasing the uveoscleral outflow. It does not cross the blood-brain barrier and is 30 times more selective for the a-2-adrenergic receptor than apraclonidine.[21] Brimonidine is believed to have neuroprotective effect, which is an important parameter of glaucoma pathogenesis.\nBrimonidine is used as a first-line therapy in patients who have contraindications to β blockers. In a double-masked, placebo-controlled trial, brimonidine was effective in reducing the IOP in patients with elevated IOP. Its efficacy was equivalent to that of apraclonidine.[22] Due to high selective action on a-2 adrenoceptor agonist activity, the IOP-lowering ability of brimonidine may be comparable with that of timolol and dorzolamide and superior to betaxolol.[23–25] Brimonidine is available as 0.2 and 0.5%, to be applied twice daily.\n","divisions":[{"label":"Title","span":{"begin":0,"end":16}},{"label":"Section","span":{"begin":18,"end":312}},{"label":"Title","span":{"begin":18,"end":27}},{"label":"Section","span":{"begin":314,"end":970}},{"label":"Title","span":{"begin":314,"end":327}},{"label":"Section","span":{"begin":972,"end":1927}},{"label":"Title","span":{"begin":972,"end":983}}],"tracks":[{"project":"2_test","denotations":[{"id":"20040958-10641099-47224441","span":{"begin":481,"end":483},"obj":"10641099"},{"id":"20040958-7887842-47224442","span":{"begin":883,"end":885},"obj":"7887842"},{"id":"20040958-12904152-47224443","span":{"begin":1266,"end":1268},"obj":"12904152"},{"id":"20040958-11901288-47224444","span":{"begin":1659,"end":1661},"obj":"11901288"},{"id":"20040958-9932994-47224445","span":{"begin":1852,"end":1854},"obj":"9932994"},{"id":"20040958-10926979-47224445","span":{"begin":1852,"end":1854},"obj":"10926979"},{"id":"T27613","span":{"begin":481,"end":483},"obj":"10641099"},{"id":"T97871","span":{"begin":883,"end":885},"obj":"7887842"},{"id":"T70089","span":{"begin":1266,"end":1268},"obj":"12904152"},{"id":"T91594","span":{"begin":1659,"end":1661},"obj":"11901288"},{"id":"T54693","span":{"begin":1852,"end":1854},"obj":"9932994"},{"id":"T16412","span":{"begin":1852,"end":1854},"obj":"10926979"}],"attributes":[{"subj":"20040958-10641099-47224441","pred":"source","obj":"2_test"},{"subj":"20040958-7887842-47224442","pred":"source","obj":"2_test"},{"subj":"20040958-12904152-47224443","pred":"source","obj":"2_test"},{"subj":"20040958-11901288-47224444","pred":"source","obj":"2_test"},{"subj":"20040958-9932994-47224445","pred":"source","obj":"2_test"},{"subj":"20040958-10926979-47224445","pred":"source","obj":"2_test"},{"subj":"T27613","pred":"source","obj":"2_test"},{"subj":"T97871","pred":"source","obj":"2_test"},{"subj":"T70089","pred":"source","obj":"2_test"},{"subj":"T91594","pred":"source","obj":"2_test"},{"subj":"T54693","pred":"source","obj":"2_test"},{"subj":"T16412","pred":"source","obj":"2_test"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"2_test","color":"#ec93b4","default":true}]}]}}