Tolerability and efficacy of dorzolamide versus acetazolamide added to timolol.
OBJECTIVE
Evaluate the safety and efficacy of dorzolamide versus acetazolamide when added to once daily 0.5% timolol maleate ophthalmic gel forming solution (timolol gel).


METHODS
This was a randomized, double-masked, multicenter, active-controlled, parallel group study of 215 patients with open-angle glaucoma or ocular hypertension. Following a two-week treatment period with timolol gel, patients with IOP > or = 22 mm Hg and who tolerated one week of acetazolamide 250-mg q.i.d. either were randomized to acetazolamide or dorzolamide 2% three times daily for 12 weeks.


RESULTS
In 155 randomized patients (dorzolamide, N = 80, acetazolamide, N = 75), compared to the dorzolamide, acetazolamide had a statistically greater number of systemic adverse events (dorzolamide 50%, acetazolamide 75%, p = 0.001), adverse events associated with carbonic anhydrase inhibitor (CAI) therapy (dorzolamide 26%, acetazolamide 53%, p < 0.001) and discontinuations due to CAI adverse experiences (dorzolamide 8%, acetazolamide 24%, p = 0.007). Intent to treat analysis found that changes from baseline in IOP were similar at both troughs (dorzolamide 1.4 +/- 0.46 mm Hg, acetazolamide 0.8 +/- 0.47 mm Hg, p = 0.386). However, per-protocol analysis found statistically improved pressure control with acetazolamide (0.1 +/- 0.42 mm Hg) compared to dorzolamide (1.9 +/- 0.43 mm Hg) (p = 0.009).


CONCLUSIONS
This study found a greater incidence of systemic and CAI adverse experiences and discontinuations due to acetazolamide compared to dorzolamide.
Stewart
William C
WC
Pharmaceutical Research Corporation, Charleston, SC 29412-2464, USA. prnc@bellsouth.net
Halper
Lee K
LK
Johnson-Pratt
Lisa
L
Polis
Adam
A
Hartenbaum
David
D
D000086:Acetazolamide / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000284:Administration, Oral; D000287:Administration, Topical; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002257:Carbonic Anhydrase Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D004338:Drug Combinations; D004359:Drug Therapy, Combination; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy*; D013449:Sulfonamides / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D013876:Thiophenes / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D013999:Timolol / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
D002257:Carbonic Anhydrase Inhibitors; D004338:Drug Combinations; D013449:Sulfonamides; D013876:Thiophenes; D013999:Timolol; C062765:dorzolamide; D000086:Acetazolamide