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acetazolamide (Rx)Brand and Other Names:Diamox Sequels

 
 
 

Dosing & Uses

AdultPediatricGeriatric

Dosage Forms & Strengths

tablet

  • 125mg
  • 250mg

powder for injection

  • 500mg

capsule, extended-release

  • 500mg
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Glaucoma

Closed-angle (acute congestive) glaucoma

  • 500 mg PO/IV, followed by 125-250 mg PO q4hr
  • Sustained-release: 500 mg PO q12hr

Open-angle (chronic simple) glaucoma

  • 250 mg-1 g PO/IV qDay or divided q6-12hr
  • Sustained-release: 500 mg PO q12hr

Secondary glaucoma

  • 500 mg PO/IV, followed by 125-250 mg PO q4hr
  • Sustained-release: 500 mg PO q12hr

Acute Altitude Sickness

Immediate release: 500-1000 mg/day PO divided q8-12hr

Extended release: 500-1000 mg PO q12-24hr

Dosing considerations

  • Start 24-48 hours before ascent and continue for 48 hours at high altitude or longer, to control symptoms if necessary

Congestive Heart Failure

CHF-associated edema

250-375 mg (5 mg/kg) PO qAM 

Seizure

8-30 mg/kg/day PO qDay or divided q12hr  

Drug-induced Edema

250-375 mg PO/IV qDay

Dosing considerations

  • Do not increase dose if edema fails to decrease following an initial response; allow instead kidney recovery by skipping medication for a day; best results obtained when given on alternate days or for 2 days followed by a day of rest

Epilepsy

Tablet: 8-30 mg/kg/day PO qDay, OR divided q6-12 hr; not to exceed 30 mg/kg/day or 1 g/day 

Extended-release capsule: Not recommended

Dosing Modifications

Renal impairment

  • CrCl 10-50 mL/min: Administer no more frequently than q12hr
  • CrCl <10 mL/min: Ineffective (avoid use)
  • Hemodialysis: 20-50% dialyzable
  • Peritoneal dialysis: Dose adjustment not necessary

Dosage Forms & Strengths

tablet

  • 125mg
  • 250mg

powder for injection

  • 500mg

capsule, extended-release

  • 500mg
more...

Epilepsy

<12 years

  • Safety and efficacy not established

>12 years

  • Tablet: 8-30 mg/kg/day PO qDay or divided q6-12 hr; not to exceed 30 mg/kg/day or 1 g/day 
  • Extended-release capsule: Not recommended

Acute Altitude Sickness

<12 years

  • Safety and efficacy not established

>12 years

  • Immediate release: 500-1000 mg/day PO divided q8-12hr
  • Extended release: 500-1000 mg PO q12-24hr

Dosing considerations

  • Start 24-48 hr before ascent and continue for 48 hr at high altitude to control symptoms, if necessary

250 mg PO qDay or q12hr; use lowest effective dose possible

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Interactions

Interaction Checker

acetazolamide and

No Results

     
     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

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            Adverse Effects

            Frequency Not Defined

            Confusion

            Convulsions

            Drowsiness

            Flaccid paralysis

            Malaise

            Paresthesias

            Photosensitivity

            Urticaria

            Anorexia

            Diarrhea

            Metallic taste

            Nausea

            Vomiting

            Hepatic disease

            Aplastic anemia

            Agranulocytosis

            Leukopenia

            Thrombocytopenia

            Thrombocytopenic purpura

            Melena

            Acidosis

            Electrolyte imbalance

            Muscle weakness

            Hematuria

            Polyuria

            Glycosuria

            Hearing dysfunction or tinnitus

            Sulfonamide type reactions

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            Warnings

            Contraindications

            Hypokalemia

            Hyponatremia

            Hyperchloremic acidosis

            Hypersensitivity to acetazolamide or sulfa

            Liver disease

            Severe renal disease or dysfunction

            Long term use in noncongestive angle-closure glaucoma

            Cirrhosis

            Long-term administration in patients with chronic, noncongestive angle-closure glaucoma

            Cautions

            Use caution in COPD, emphysema, and concomitant high-dose aspirin

            Use caution in diabetes, respiratory acidosis, and hepatic impairment

            Adverse drug reactions common to sulfonamide derivatives; Stevens-Johnson syndrome and toxic epidermal necrolysis (TEN) may occur

            May impair alertness and/or physical coordination

            FDA-approved product labeling for many medications have included a broad contraindication in patients with a prior allregic reaction to sulfonamides; however, recent studies have suggested that crossreactivity between antibiotic sulfonamides and nonantibiotic sulfonamides is unlikely to occur

            May impair alertness and/or physical coordination

            Severe adverse effects including tachypnea, anorexia, coma, lethargy, and death reported with high-dose aspirin; use caution or avoid administration

            Increasing dose does not increase diuresis; may instead increase the incidence of paresthesia and/or drowsiness

            IM administration not recommended due to alkaline pH, which may cause pain

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            Pregnancy & Lactation

            Pregnancy category: C

            Lactation: Enters breast milk; not recommended

            Pregnancy Categories

            A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

            B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

            C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

            D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

            X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

            NA:Information not available.

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            Pharmacology

            Mechanism of Action

            Carbonic anhydrase inhibitor that decreases rate of aqueous humor formation, in that way decreasing intraocular pressure

            Inhibits H+ ion excretion in renal tubule, increasing sodium, potassium, bicarbonate, and water excretion and producing alkaline diuresis

            Inhibits carbonic anhydrase in CNS, which in turn decreases abnormal and excessive discharge from the CNS neurons

            Absorption

            Bioavailability: Rapidly absorbed orally

            Tablet

            • Onset: 1-1.5 hr
            • Duration: 8-12 hr
            • Peak plasma time: 1-4 hr

            Sustained-release

            • Onset: 2 hr
            • Duration: 18-24 hr
            • Peak plasma time: 8-18 hr

            IV

            • Onset: 5-10 min
            • Duration: 4-5 hr
            • Peak plasma time: 15 min

            Distribution

            Protein bound: 70-90%

            Vd: 0.2 L/kg

            Metabolism

            Metabolism: None

            Elimination

            Half-life: 2-4 hr (tablet)

            Dialyzable: Yes (hemodialysis)

            Excretion: Urine 90%

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            Administration

            IV Incompatibilities

            Additive: Multivitamins

            Y-site: Diltiazem(?), multivitamins

            IV Compatibilities

            Solution: Compatible with most common solvents

            Additive: Cimetidine, ranitidine

            IV Preparation

            Standard diluent: 500 mg/50 mL D5W

            Minimum volume: 50 mL D5W

            IV Administration

            IV push: 100-500 mg/min

            Infusion: 4-8 hr

            Storage

            Store intact vials at room temperature

            May store reconstituted solution in refrigerator for 3 days or at room temperature for 12 hr

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            Images

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            Formulary

            FormularyPatient Discounts

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            The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

            Tier Description
            1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
            2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
            3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
            4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
            NC NOT COVERED – Drugs that are not covered by the plan.
            Code Definition
            PA Prior Authorization
            Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
            QL Quantity Limits
            Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
            ST Step Therapy
            Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
            OR Other Restrictions
            Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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