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methazolamide (Neptazane)

 

Classes: Antiglaucoma, Carbonic Anhydrase Inhibitors

Dosing and uses of Methazolamide (Neptazane)

 

Adult dosage forms and strengths

tablet

  • 25mg
  • 50mg

 

Glaucoma

50-100 mg PO BID/TId

 

Other Indications & Uses

Off-label: Altitude sickness

 

Pediatric dosage forms and strengths

Safety and effecacy not established

 

Methazolamide (Neptazane) adverse (side) effects

>10%

Drowsiness

Paresthesias

Anorexia

Nausea

Vomiting

 

Frequency not defined

Sulfonamide-type rxns

Acidosis

Electrolyte imbalance

Glycosuria

Hematuria

Thrombocytopenia

Hepatic dysfunction

Tinnitus

 

Warnings

Contraindications

Hypokalemia, hyponatremia, hyperchloremic acidosis, cirrhosis, severe liver or renal impairment, adrenal gland failure

 

Cautions

COPD, emphysema, concomitant high-dose aspirin or steroid therapy, or hepatic insufficiency

ADRs common to sulfonamide derivatives

Stevens-Johnson syndrome and toxic epidermal necrolysis may occur

 

Pregnancy and lactation

Pregnancy category: C

Lactation: not known if crosses in to breast milk, avoid

 

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.

 

Pharmacology of Methazolamide (Neptazane)

Mechanism of action

Carbonic anhydrase inhibitor, decr rate of aqueous humor formation and decreased IOp

 

Pharmacokinetics

Half-life: 14 d

Onset: 2-4 hr

Max Effect: 6-8 hr

Duration: 10-18 hr

Bioavailability: absorbed more slowly than acetazolamide

Excretion: urine 15%