Methazolamide

— THERAPEUTIC CATEGORIES —
  • Glaucoma
PAGE CONTENTS
  • Jump to Section
  • Generic Name & Formulations
  • Indications
  • Dosage and Administration
  • Contraindications
  • Boxed Warnings
  • Warnings/Precautions
  • Pharmacokinetics
  • Interactions
  • Adverse Reactions
  • Clinical Trials
  • Note
  • Patient Counseling

    • Methazolamide Generic Name & Formulations

    Legal Class

    Rx

    General Description

    Methazolamide 25mg, 50mg; tabs.

    Pharmacological Class

    Carbonic anhydrase inhibitor.

    How Supplied

    Contact supplier

    Manufacturer

    Various generic manufacturers

    Methazolamide Indications

    Indications

    Ocular conditions where lowering intraocular pressure would be of therapeutic benefit (eg, chronic open-angle glaucoma, secondary glaucoma, pre-op in acute angle-closure glaucoma).

    Methazolamide Dosage and Administration

    Adult

    50–100mg 2–3 times daily.

    Children

    Not recommended.

    Methazolamide Contraindications

    Contraindications

    Hypokalemia. Hyponatremia. Severe renal, hepatic, or adrenocortical impairment. Hyperchloremic acidosis. Cirrhosis. Long-term use in angle-closure glaucoma.

    Methazolamide Boxed Warnings

    Not Applicable

    Methazolamide Warnings/Precautions

    Warnings/Precautions

    Sulfonamide allergy. Respiratory impairment (eg, pulmonary obstruction or emphysema). Do baseline CBC and platelet counts before starting and during therapy. Monitor serum electrolytes periodically. Pregnancy (Cat.C). Nursing mothers: not recommended.

    Warnings/Precautions

    • Severe reactions to sulfonamides may occur including Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia, and other blood dyscrasias. 

    • Discontinue use if hypersensitivity or other serious reactions occur.

    • Use caution for patients receiving high-dose aspirin and methazolamide concomitantly.

    • Upon initial administration of methazolamide, potassium excretion is increased which could result in hepatic coma in patients with cirrhosis or hepatic insufficiency.

    • Use caution in patients with pulmonary obstruction or emphysema because methazolamide may precipitate or aggravate acidosis.

    Pregnancy Considerations

    Teratogenic effects

    • Pregnancy Category C: No adequate and well controlled studies in pregnant women. Only use during pregnancy if the potential benefit justifies the potential risk to the fetus.

    Nursing Mother Considerations

    • Not known whether this drug is excreted in human milk.

    • Due to the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

    Pediatric Considerations

    Safety and effectiveness of methazolamide in children have not been established.

    Methazolamide Pharmacokinetics

    Elimination

    Renal. Half-life: ~14 hours.

    Methazolamide Interactions

    Interactions

    May inhibit renal excretion of basic drugs and promote excretion of acidic drugs. Caution with high-dose aspirin; may increase salicylate toxicity. Caution with corticosteroids; may develop hypokalemia.

    Methazolamide Adverse Reactions

    Adverse Reactions

    Paresthesias, tinnitus, fatigue, malaise, anorexia, GI upset, dysguesia, drowsiness, confusion, metabolic acidosis, electrolyte imbalance, transient myopia; hepatic insufficiency, blood dyscrasias, anaphylaxis, urticaria, melena, hematuria, glycosuria, flaccid paralysis, photosensitivity, convulsions; rare: crystalluria, renal calculi.

    Methazolamide Clinical Trials

    See Literature

    Methazolamide Note

    Notes

    Formerly known under the brand name Neptazane.

    Methazolamide Patient Counseling

    Patient Counseling

    • Use caution for patients receiving high-dose aspirin and methazolamide concomitantly.

    • Advise patients to detect adverse reactions common to all sulfonamide derivatives, and discontinue methazolamide if it develops and institute appropriate therapy.

    • Latest News Your top articles for Wednesday

    • Haymarket Medical NetworkTop Picks

    • Loading...

      Continuing Medical Education (CME/CE) Courses

      Show More