Handbook of clinical drug data.pdf - Me and My Life

506 CENTRAL NERVOUS SYSTEM DRUGSAdministration and Adult Dosage. Ophth for primary open-angle glaucoma(brinzolamide) 1 drop tid; (dorzolamide) 1 drop tid. When used adjunctively, dorzolamideis administered bid. 366 PO for primary open-angle glaucoma (acetazolamide)SR cap 500 mg bid has been better tolerated than tablets; Tab 125 mgq 4 hr to 250 mg qid. Dosages >1 g/day are no more effective. (Dichlorphenamide)100–200 mg priming dose, followed by 100 mg q 12 hr until desired responseis obtained, then 25–50 mg daily to tid. (Methazolamide) 50–100 mg bidtid.PO for prevention of altitude sickness (acetazolamide) 750 mg/day. 367 (SeeNotes.)Special Populations. Pediatric Dosage. Safety and efficacy not established. However,dorzolamide 2% ophthalmic solution is used in infantile glaucoma, and acetazolamide5–10 mg/kg qid has been used when an oral CAI was necessary.341,364,368Geriatric Dosage. Same as adult dosage.Dosage Forms. (Acetazolamide) Tab 125, 250 mg; SR Cap 500 mg; Inj 500 mg.(Brinzolamide) Ophth Susp 1%. (Dichlorphenamide) Tab 50 mg. (Dorzolamide)Ophth Soln 2%. (Methazolamide) Tab 25, 50 mg.Patient Instructions. (See Class Instructions.) Dorzolamide Tell your doctor ifyou experience itching, redness, swelling, or other sign of eye or eyelid irritation.This medication can cause you to have blurred vision for a short period. Makesure you know how to react to this medication before you drive, use a machine, ordo anything else that might be dangerous if you cannot see properly. Dorzolamidecan cause your eyes to become more sensitive to light. Wearing sunglasses andavoiding exposure to bright light can lessen the discomfort. 338Pharmacokinetics. Onset and Duration. (Acetazolamide) Tab peak IOP reduction2–6 hr, duration 4–12 hr; 341,364 SR cap onset 2–4 hr, peak 4–8 hr, duration 12–24hr. 341,364 (Brinzolamide) onset 12 hr. 369 (Dichlorphenamide)onset 30 min, peak 2 hr, duration 6 hr. (Dorzolamide) onset 10 mg/L for 10 hr. 90% bound to plasma proteins; elimination isby active renal tubular secretion. 364 (Methazolamide) well absorbed and distributedin plasma, CSF, aqueous humor, red blood cells, bile, and extracellular fluid.Peak serum concentrations after 50 and 100 mg bid dosages are 5.1 and 10.7 mg/L,respectively. V dss is 17–23 L. Renal clearance accounts for 20–25% of the totalclearance, with about 25% of the drug eliminated in the urine unchanged. Brinzolamideand dorzolamide are systemically absorbed and bind to carbonic anhydrasein erythrocytes with terminal half-lives of 111 and 147 days, respectively;however, there is only a 21% decrease in baseline carbonic anhydrase activity, farbelow the 99% inhibition level necessary to induce systemic effects. 368 Laboratoryvalues of patients receiving dorzolamide did not indicate metabolic acidosis orelectrolyte imbalances such as those with long-term systemic CAIs. 370