What is methazolamide used for?

Methazolamide is used to lower pressure inside the eye for conditions like chronic open-angle glaucoma and secondary glaucoma.

Can methazolamide cause skin rashes?

Yes, rare but very serious skin reactions like Stevens-Johnson syndrome have occurred with methazolamide.

Is it safe to take methazolamide if I am pregnant?

Methazolamide can cause skeletal issues in a fetus; it should only be used if the benefit is greater than the risk.

What should I do if I experience a tingling sensation?

Tingling in your hands or feet is a common side effect of methazolamide, but you should report new sensations to your doctor.

Can I take aspirin while using methazolamide?

You should be very careful with high-dose aspirin, as it can lead to serious problems like coma or death when combined with methazolamide.

Will methazolamide affect my breastfeeding?

Because it is unknown if the drug passes into milk and could harm an infant, you should discuss your options with a doctor.

What are the common stomach side effects of methazolamide?

Common stomach-related issues include nausea, vomiting, and diarrhea.

Does methazolamide cause vision changes?

Yes, temporary nearsightedness (myopia) has been reported, but it usually goes away when the medicine is stopped or reduced.

Methazolamide | CAS 2101958-72-7 | FLOSMHQXBMRNHR

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Carbonic Anhydrase Inhibitor

Methazolamide is an oral medication used to treat certain eye conditions, such as glaucoma, by lowering the pressure inside the eye. It belongs to a class of drugs called carbonic anhydrase inhibitors. Because it is a sulfonamide, it can cause serious allergic reactions in some people and should be used with caution if you have kidney, liver, or adrenal gland issues.

How it worksMethazolamide works by blocking enzymes called carbonic anhydrases. This action helps reduce the pressure inside your eye.

Brand names:NEPTAZANE

Used for

Chronic open-angle glaucomaSecondary glaucomaReducing eye pressure before surgery for acute angle-closure glaucoma

Conditions

Chronic open-angle glaucomaSecondary glaucomaAcute angle-closure glaucoma (preoperatively)

Class

Carbonic Anhydrase InhibitorSulfonamideOcularMetabolicHematologic

How to take

FormsTablet

RoutesOral

The usual effective dose is between 50 mg and 100 mg, taken two or three times every day.

Methazolamide can be used along with other eye medications that help constrict the pupil or reduce fluid buildup in the eye.

Key warnings

·Rare but fatal severe skin reactions and blood disorders can occur due to the sulfonamide component.
·Taking high doses of aspirin while using methazolamide can lead to serious issues like coma or death.
·If you have a known allergy to sulfonamides, do not take this medication.
·Long-term use may not be suitable for certain types of angle-closure glaucoma.

Do not use if

·Low sodium or potassium levels
·Severe kidney or liver disease
·Adrenal gland failure
·Hyperchloremic acidosis
·Cirrhosis (may cause liver-related brain issues)
·Certain types of angle-closure glaucoma

Side effects

Common

Tingling feeling in hands or feetHearing changes or ringing in the earsFatigue or feeling unwellLoss of appetiteChanges in tasteNausea, vomiting, or diarrheaIncreased urinationDrowsiness or confusion

Serious

·Severe skin reactions (like Stevens-Johnson syndrome)
·Severe liver problems
·Serious blood disorders (like anemia)
·Metabolic acidosis (imbalance in blood acid levels)
·Electrolyte imbalances
·Temporary blurry vision (myopia)
·Kidney stones

Seek help if

·Severe skin rashes or blistering
·Signs of severe allergic reaction
·Extreme fatigue or confusion
·Changes in urination or blood in urine

Interactions

·Use caution with steroid therapy as it may lower potassium levels.
·Avoid taking high doses of aspirin with methazolamide due to risks of lethargy, coma, or death.
·Known interactions include COSOPT, AZOPT, TOPAMAX, DIAMOX, DARANIDE, and ATMEKSI.

Special populations

PregnancyMethazolamide can cause birth defects (such as skeletal issues) in animal studies. It should only be used during pregnancy if the benefits outweigh the risks to the baby.

BreastfeedingIt is unknown if this drug passes into breast milk. Since infants can have serious reactions to this medication, you should talk to your doctor about whether to stop nursing or stop the medication.

PediatricThe safety and effectiveness of methazolamide in children have not been established.

Talk to your doctor

Monitor

·Electrolyte levels (especially potassium)
·Blood pH levels
·Skin reactions
·Vision changes

Questions to ask

·Do I have any kidney or liver issues that would make this unsafe?
·Should I avoid certain over-the-counter pain relievers like aspirin?
·How will this affect my electrolyte levels?
·Is it safe to continue breastfeeding while taking this?

Pharmacokinetics

Onset1 to 2 hours after dosing

BioavailabilityWell absorbed from the gastrointestinal tract

Protein bindingApproximately 55%

Practical

OverdoseThere is no specific antidote for an overdose. Treatment focuses on managing symptoms and restoring the body's natural balance of electrolytes and blood pH.

Ingredients

Inactive

colloidal silicon dioxidecroscarmellose sodiumdibasic calcium phosphate dihydratemagnesium stearate (powder)microcrystalline cellulose

Educational summary derived from FDA labeling, AI-assisted. Not medical advice — consult a healthcare professional. Updated 2026-04-25.