IN THE TREATMENT OF GLAUCOMA THE USUAL DOSE IS 250 TO 1000 MG DAILY BY MOUTH; DIVIDED DOSES SHOULD BE USED FOR AMOUNTS GREATER THAN 250 MG DAILY. MODIFIED-RELEASE PREPARATIONS ARE ALSO AVAILABLE. ALTHOUGH NOT LICENSED FOR CHILDREN IN THE UK, THE BNFC SUGGESTS THAT THOSE AGED 1 MONTH TO 12 YEARS MAY BE GIVEN ACETAZOLAMIDE IN ORAL DOSES OF 10 TO 20 MG/KG DAILY, TO A MAXIMUM OF 750 MG DAILY, IN 2 TO 4 DIVIDED DOSES.
EPILEPSY :
ACETAZOLAMIDE IS ALSO USED, EITHER ALONE OR WITH OTHER ANTIEPILEPTICS, FOR THE TREATMENT OF VARIOUS FORMS OF EPILEPSY IN ORAL DOSES OF 250 TO 1000 MG DAILY IN DIVIDED DOSES. LICENSED DRUG INFORMATION IN THE UK SUGGESTS AN ORAL DOSE FOR CHILDREN OF 8 TO 30 MG/KG DAILY. THE BNFC RECOMMENDS AN INITIAL ORAL DOSE OF 2.5 MG/KG 2 OR 3 TIMES DAILY IN NEONATES AND CHILDREN UP TO 12 YEARS OF AGE; THIS MAY THEN BE INCREASED TO A MAINTENANCE DOSE OF 5 TO 7 MG/KG 2 OR 3 TIMES DAILY. THE TOTAL DAILY DOSE FOR CHILDREN SHOULD NOT EXCEED 750 MG.
WHEN ORAL DOSING IS IMPRACTICABLE, ACETAZOLAMIDE MAY BE GIVEN PARENTERALLY AS THE SODIUM SALT; ACETAZOLAMIDE SODIUM 275 MG IS EQUIVALENT TO ABOUT 250 MG OF ACETAZOLAMIDE. IT MAY BE GIVEN BY INTRAMUSCULAR INJECTION BUT THE INTRAVENOUS ROUTE IS PREFERRED DUE TO THE ALKALINITY OF THE SOLUTION. DOSES ARE SIMILAR TO THOSE GIVEN ORALLY.
ACETAZOLAMIDE IS ALSO USED TO PREVENT OR AMELIORATE THE SYMPTOMS OF HIGH-ALTITUDE DISORDERS. PROMPT DESCENT WILL STILL BE NECESSARY IF SEVERE SYMPTOMS SUCH AS CEREBRAL OEDEMA OR PULMONARY OEDEMA OCCUR. THE USUAL ORAL DOSE IS 500 TO 1000 MG DAILY IN DIVIDED DOSES. IT MAY ALSO BE GIVEN AS A MODIFIED-RELEASE PREPARATION.
METABOLIC ALKALOSIS :
ACETAZOLAMIDE ALSO INCREASES THE EXCRETION OF BICARBONATE AND OF CATIONS, CHIEFLY SODIUM AND POTASSIUM, BY INHIBITING THE REACTION CATALYSED BY CARBONIC ANHYDRASE IN THE RENAL TUBULES, AND SO PROMOTES AN ALKALINE DIURESIS. WHEN GIVEN BY MOUTH AS AN IMMEDIATE-RELEASE PREPARATION, ITS EFFECT BEGINS WITHIN 60 TO 90 MINUTES AND LASTS FOR 8 TO 12 HOURS. HOWEVER, CONTINUOUS USE IS ASSOCIATED WITH METABOLIC ACIDOSIS AND AN ACCOMPANYING LOSS OF DIURETIC ACTIVITY. THEREFORE, ALTHOUGH ACETAZOLAMIDE HAS BEEN USED AS A DIURETIC, IT HAS LARGELY BEEN SUPERSEDED BY DRUGS SUCH AS THE THIAZIDES OR FUROSEMIDE.
FOR DIURESIS THE USUAL DOSE IS 250 TO 375 MG BY MOUTH AND IS GIVEN EITHER ONCE DAILY OR ON ALTERNATE DAYS; INTERMITTENT THERAPY IS REQUIRED FOR A CONTINUED EFFECT.
RESPIRATORY STIMULANT: CAN BE USED AS STIMULANT IN DOSES OF 250 MG BD.
METABOLIC ALKALOSIS : 500 MG AS A SINGLE DOSE BY IV ROUTE.