Anti glaucoma drugs

Mechanism of action, Uses, sideeffect, contraindications of Commonly used anti glaucoma drugs.
1.Prostaglandin analogue
2.Betablocker
3.Alpha agonists
4.Miotics
5.carbonic anhydrase inhibitor

1. ANTI-GLAUCOMA DRUGS DR.ANKITA MAHAPATRA 1 ST YR PG, DEPT OF OPHTHALMOLOGY VSSIMSAR,BURLA

2. AIM OF GLAUCOMA TREATMENT IOP to levels that permit normal functioning of OPTIC NERVE and prevent further damage. Medications directed towards preventing neural cell loss (under investigation): MEMANTIN , BRIMONIDINE

3. INREASE TRABECULAR OUTFLOW: 1.MIOTICS(PILOCARPINE) 2.EPINEPHRINE,DIPIVEFRINE 3.BIMATOPROST INCREASE UVEOSCLERAL OUTFLOW: 1.PROSTAGLANDIN (LATANOPROST) 2.ALPHA AGONISTS: EPINEPHRINE, DIPIVEFRINE BRIMONIDINE APRACLONIDINE DECREASE AQUEOUS OUTFLOW: 1.CAI : ACETAZOLAMIDE, DORZOLAMIDE 2.ALPHA AGONISTS: EPINEPHRINE, DIPIVEFRINE,CLONIDINE, BRIMONIDINE, APRACLONIDINE 3. BETA BLOCKERS: TIMOLOL, BETAXOLOL,LEVOBUNOLOL DRUGS:

4. PARASYMPATHOMIMETICS( CHOLINERGICS)

5. PILOCARPINE : INDICATIONS : Long-term t/t of elevated IOP in patients having persistently occludable angle despite Laser iridotomy Pplx of Angle closure Glaucoma prior to Iridectomy. CONTRAINDICATIONS: Uveitic Glaucoma Blue eyes show maximal ocular hypotensive responses Darkly pigmented eyes demonstrate a relative resistance to IOP reduction Miotics better tolerated in Aphakic eye than in Phakic eye.

6. AVAILABLE PREPARATIONS: A. Eyedrops Available in 1%, 2% and 4% strengths. The onset of action:20 minutes Peaks in 2 hours Duration of effect :4-6 hours Prescribed every 6 or 8 hourly. B. Ocuserts P ilo-20 & Pilo-40 Changed once in a week. Pilo-20 used in patients controlled with 2 percent or less concentration of eyedrops pilo-40 in those requiring higher concentration of eyedrops. C. Pilocarpine gel (4%) Causes 18-25% fall in IOP.

7. CARBACHOL : INDICATIONS: alternative to pilocarpine in resistant or tolerant cases. PREPARATIONS: 0.75% , 3% DOSAGE: Duration of onset : 40 mins , Duration of effect : 12 hours 2-3 times/d SIDE-EFFECTS:

8. SYMPATHOMIMETICS

9. 1.Epinephrine. Preparations : 0.5% , 1 % , 2% eyedrops. Dosage : The action starts within 1 hour and lasts up to 12-24 hrs 2. Dipivefrine ( Propine or dipivalylepinephrine ): Prodrug converted to epinephrine after its absorption into the eye. More lipophilic than epinephrine (corneal penetration increased by 17 times). Preparations : 0.1 % eyedrops Dosage : Action and efficacy similar to 1% epinephrine. Twice daily

10. CLONIDINE : Decrease aqueous production Increase both trabecular and uveoscleral outflow (lesser extent) PREPARATIONS : 0.06% , 0.125 % 6-8 hrly SIDE EFFECTS : Conjunctival blanching Sedation Dry mouth Hypotension

11. APRACLONIDINE : Decrease aqueous production Decrease episcleral venous pressure Improves Trabecular outflow peak action : 2 hrs Duration of action : 12 hrs PREPARATIONS: 0.50 , 1 % 8hrly USES: Post- Laser trabeculoplasty & YAG laser iridotomy & posterior capsulotomy & cataract extraction SIDE EFFECTS : Allergic reaction Tachyphlaxis Conjunctival blanching Follicular conjunctivitis BRIMONIDINE : More selective alpha-2 action Less Tachyphylaxis ,Ocular allergic Reactions III. Not to be used in infants and young children, as risk of respi depression, Somnolence, Hypotension, seizure IV. Peak IOP reduction 26% ( 2 hours postdose ) Caution recommended when using with MAOI, TCA

12. ADRENERGIC ANTAGONISTS(BETA BLOCKERS)

13. MECHANISM OF ACTION : Topical β-blockers reduce aqueous formation by 20% to 50% in awake humans. β-blockers are less effective during sleep Systemic absorption, leads to IOP lowering in untreated contralateral eye also.

14. DRUGS : CARTELOL HAS LEAST EFFECT ON LIPID PROFILE

15. Beta-blockers have very good synergistic effect when combined with Miotics ; and are thus often used in combination in patients with POAG, unresponsive to the single drug. Dosing first thing in the morning preffered , to blunt an early morning pressure rise. ADDITIVE TO: Miotics Adrenergic agonists Carbonic anhydrase inhibitors PG Analogues Timolol and Latanoprost combination causes an additional IOP reduction of 13-37% Betaxolol is the beta blocker of choice In patients at risk for pulmonary diseases

16. CONTRAINDICATIONS: Bronchial Asthma Emphysema COPD Heart blocks, Congestive Heart Failure Cardiomyopathy. known drug allergies . SIDE EFFECTS : Reduced glucose tolerance, masking of hypoglycemic signs and symptoms Occurs in Diabetics. Abrupt withdrawal of beta blockers can exacerbate Symptoms of Hyperthyroidism.

17. PROSTAGLANDIN ANALOGUES: MECHANISM OF ACTION :

18. DRUGS: UNOPROSTONE increases retinal blood flow

19. ADVANTAGES : Once daily dosing Lack of cardiopulmonary side effect Additive to other anti-glaucoma medications SIDE EFFECTS : Conjunctival hyperaemia SPK CME Anterior uveitis Blurred vision CONTRAINDICATIONS : Ocular infection Inflammation Increased pigmentation of iris, lashes Hypertrichosis Trichiasis Districhiasis Hair growth around eye

20. CARBONIC ANHYDRASE INHIBITOR MECHANISM OF ACTION : Potent and most commonly used Systemic Anti-Glaucoma drugs >90% of ciliary enzyme activity must be abolished to decrease aqueous production and IOP

21. DRUGS :

22. ACETAZOLAMIDE: Reduces aqueous production by 30-40% USE: control of very high IOP in Acute angle closer Refusal of surgery DOSAGE: 250mg tabs 6hrly SR 500mg BD 500mg IV lowers IOP within 20 minutes SIDE EFFECTS (Dose related): Altered taste loss of appetite Paraesthesia of hands, feet Sulfa allergy Hypokalaemia Metabolic acidosis Renal stones Blood dyscrasias

23. DORZOLAMIDE: Topical agent PREPARATION: 2% FALL IN IOP: 13-24% SIDE EFFECTS: Punctate keratitis Bitter taste allergic reaction Transient burning d/t decrease in ph BRINZOLAMIDE: 1% preparations Suspension causes white deposits in tear film Eyes with compromised endothelial function, are at risk of corneal decompensation.

24. HYPEROSMOTICS : IV: Mannitol ORAL: Glycerol MECHANISM OF ACTION :

25. MANNITOL: 20% 0.5- 2.0 g/kg Body weight s/e: IOP rebound Increased aqueous flare headache Mental confusion Backache CHF, MI Subdural, Subarachnoid haemorrhage Larger the dose, more rapid the administration, greater decrease in IOP. Rarely administered for longer duration, cause effects are transient, result of rapid reequilibration of Osmotic gradient. Less effective overtime, rebound increase in IOP may occur. GLYCEROL: Concentration 50% 1-1.5 g/kg dosing It precipitates hyperglycaemia, Ketoacidosis in DIABETICS Hyperosmotics are contraindicated in patients with renal failure or on dialysis

26. FIXED COMBINATIONS: COMPOUNDS CONCENTRATION TIMOLOL/BRINZOLAMIDE 0.5%/1% TIMOLOL/DORZOLAMIDE 0.5%/2% TIMOLOL/LATANOPROST 0.5%/ 0.005% TIMOLOL/TROVAPROST 0.5%/ 0.004% TIMOLOL/BIMATOPROST 0.5%/0.03% TIMOLOL/BRIMONIDINE TARTARATE 0.5%/ 0.2% DOSING BD BD OD, AT NIGHT TIME OD, AT NIGHT TIME OD, AT NIGHT TIME BD

27. I] PRIMARY OPEN ANGLE GLAUCOMA (A ) SINGLE DRUG THERAPY 1. Topical beta-blockers: DoC, 1st line Timolol maleate, Betaxolol, Levobunolol, Carteolol 2. Latanoprost: 1st line 3. Dorzolamide: 2nd line 4. Pilocarpine: 2nd line 5. Adrenergic drugs: Dipivefrine hydrochloride ( combined with beta-blockers in patients where other drugs are contraindicated ) ( B) COMBINATION TOPICAL THERAPY If one drug is not effective, then a combination of two drugs—one drug which decreases aqueous production (timolol or other betablocker, or brimonidine or dorzolamide) and other drug which increases aqueous outflow (latanoprost or brimonidine or pilocarpine) may be used.

28. II] ACUTE PRIMARY ANGLE-CLOSURE GLAUCOMA Medical therapy is instituted as an emergency and temporary measure before the eye is ready for operation; 1. Systemic hyperosmotic agent intravenous mannitol (1 gm/kg body weight) 2. Acetazolamide 500 mg intravenous injection followed by 250 mg tablet should be given 3 times a day. 3. Analgesics and anti-emetics 4. Pilocarpine eyedrops 2 percent pilocarpine should be administered every 30 minutes for 1-2 hours and then 6 hourly 5. Beta blocker eyedrops like 0.5 percent timolol maleate or 0.5 percent betaxolol should also be administered twice a day to reduce the IOP. 6. Corticosteroid eyedrops like dexamethasone or betamethasone should be administered 3-4 times a day to reduce the inflammation