CARBONIC ANHYDRASE INHIBITORS
Commonly Used Drugs
Acetazolamide (Diamox) 125mg, 250mg, 500mg
Methazolamide (Neptazane) 25mg, 50mg
Uses of This Medicine
Carbonic anhydrase inhibitors are used to lower eye pressure in
the treatment of glaucoma. Carbonic anhydrase inhibitors lower eye
pressure by reducing the pressure of aqueous (eye fluid). They may
be used alone or in combination with other medications. These
medications are given either as eye drops, or as pills that are
Before Using This Medicine
Be sure to tell your doctor if you:
- Are allergic to any medications, especially Sulfa drugs
- Are pregnant or breast feeding
- Are taking prescription or non-prescription medications,
- Have any other medical problems including severe kidney
disease, kidney stones, liver disease (cirrhosis), adrenal
dysfunction, or gout
Dosage and Administration
In glaucoma, carbonic anhydrase inhibitors are given as eye
drops or as oral tablets or slow release capsules. The usual dose of
Trusopt or Azopt is 1 drop in the affected eye every 12 or 8 hours.
The usual dose of Diamox for an adult ranges from 125mg to 250mg
every 6 hours, or a 500mg sustained release capsule every 12 hours.
Neptazane is usually given as 25 to 50mg every 12 or 8 hours. Use
this medication only as directed by your doctor. If you miss a dose,
do not try to catch up on this dosage by taking more than one dose
at a time, since serious side effects may occur.
(this is a list of the most common side effects; for a
complete list, see the insert provided with your medication)
Side effects of the drops include transient burning and stinging of
the eye, blurred vision, and a bitter taste in the throat. Some
people experience redness, irritation, or eye allergy. Less common
effects of the drops include headache, fatigue, skin rash, and
Tingling or feeling of pins and needles in the hands, face or feet
is the most common side effect of the oral form of this medication.
Other side effects of the oral medication include fatigue, loss of
appetite, weight loss, depression, gastrointestinal distress, loss
of libido, and impotence. Stomach upset may be reduced by taking the
medication with food. Kidney stones can occur, but most commonly in
people who have a history of kidney stones within the past 5 years.
Blood abnormalities and severe allergic reactions are very rare, but
are the most severe side effect, and may be a fatal side effect of
this medication. These reactions are extremely rare, and impossible
to predict. These reactions could potentially occur with drops,
Your doctor must be informed immediately if you notice easy
bruising, bleeding, skin rash or if you experience a change in your
overall well being while using these medications. Always inform all
of your doctors about all medicines you take, so that they may be
aware of potential drug interactions.
You must keep your regularly scheduled appointment with your eye
doctor so the effect of this medicine can be monitored. All
medicines should be taken exactly as prescribed. If you experience
any problems with this medication, call your doctor immediately.