Carbonic Anhydrase Inhibitor (Oral, Parenteral)

Diuretic and anti-convulsant carbonic anhydrase inhibitors work by reducing water pressure from fluid in the eyeball to treat a range of conditions, including epilepsy and glaucoma.

Overview

Carbonic anhydrase inhibitors are medications used to treat glaucoma, epilepsy, and airsickness. It reduces the amount of fluid produced in the body, especially in the eyes, therefore reducing water pressure in the body.

Conditions treated:

  • Glaucoma
  • Epilepsy
  • Airsickness

Type of Medicine:

  • Anti-convulsant
  • Diuretic

Side Effects

Mild Side Effects

Patients taking carbonic anhydrase inhibitors may experience some unwanted side effects in addition to the desired therapeutic effects of carbonic anhydrase inhibitors. Some of these side effects are just a result of your body getting used to the medication, and should subside or go away over the course of treatment. Tell your doctor if any of these side effects do not subside, become bothersome, or get worse over the course of treatment. Your doctor may be able to suggest treatments or remedies for these side effects. Mild side effects may include gastrointestinal symptoms such as constipation or diarrhea, a loss of appetite, nausea that may include vomiting, a metallic taste in the mouth, or a loss of the sensation of taste or smell. You may experience a general feeling of discomfort or illness, headaches, nervousness or unusual irritability, a feeling of dizziness or lightheadedness, unusual drowsiness, or an increased sensitivity of your eyes to sunlight. You may feel numbness, burning, or tingling in extremities such as your hands, fingers, feet or toes, or in mucous membranes such as the mouth, lips, tongue, or anus. You may experience a feeling of choking or having a lump in the throat. You may experience weight loss. If these symptoms become bothersome, check with your doctor.

Serious Side Effects

Some side effects of carbonic anhydrase inhibitors can cause more serious health problems in the body, or can be symptoms of health problems triggered by taking carbonic anhydrase inhibitors. If you experience any of these side effects, check with your doctor immediately. You may need additional medical attention or treatment for these side effects, or your doctor may decide to change or stop your dosage of carbonic anhydrase inhibitors.

You may experience changes in your vision, such as problems seeing faraway objects. You may experience shortness of breath or trouble breathing, which should be reported to your doctor immediately. You may experience problems related to the urinary tract such pain in your lower back, as difficult urination, pain or burning when you urinate, a sudden decrease in the amount of urine you produce, or blood in your urine. You may experience mental depression, unusual tiredness or weakness, unsteadiness or clumsiness, or convulsions or seizures. You may have pale stools, or stools that are bloody, black, and tarry. You may contract a fever. You may experience ringing or buzzing in the ears, a sore throat, uncontrollable muscle trembling, or unusual bleeding or bruising. You may notice itchy skin, a skin rash, hives, or sores. Symptoms of an extreme loss of potassium include severe dry mouth and increased thirst, mental changes or changes in mood, an irregular heartbeat or weak pulse, nausea or vomiting, muscle cramps or muscle pain, and unusual tiredness or weakness. If you experience any of these symptoms, check with your doctor immediately. Some of these symptoms may require immediate medical assistance depending on the symptom cluster and severity of your symptoms.

Acetazolamide Side Effects

When taking carbonic anhydrase inhibitors or any medication with acetazolamide, you may experience some side effects of acetazolamide. Some of these side effects are normally mild, and are a result of your body adjusting to the medication. These side effects should subside or go away entirely soon during the course of treatment if your carbonic anhydrase inhibitor is taken regularly and on time. Mild side effects include dizziness, lightheadedness, tiredness, drowsiness, and confusion. You may experience gastrointestinal side effects such as a loss of appetite, stomach upset, nausea, diarrhea, or vomiting. You may experience changes in your sense of taste, a loss of appetite, or a dry mouth. You may experience headaches, a tingling feeling, or some ringing in the ears. You may experience blurred vision and an increased amount of urine during the first few days of taking carbonic anhydrase inhibitors, but these side effects should go away quickly. If any of these side effects do not subside, if they worsen, or if they become bothersome, let your doctor know. Your physician may be able to suggest treatments that may help you deal with these symptoms.

Some side effects of acetazolamide may be more serious, or can point to more serious underlying health problems. You may experience hearing loss, unusual tiredness, or increased growth of body hair. You may also experience severe abdominal or stomach pain, or persistent nausea that may include vomiting. If you experience these symptoms, contact your doctor immediately.

Dichlorphenamide Side Effects

While taking carbonic anhydrase inhibitors or medications with dichlorphenamide, you may experience some side effects of dichlorphenamide. If you experience these side effects while taking carbonic anhydrase inhibitors, you will need to check with your doctor immediately. Some of these side effects may be symptoms of serious health problems, or may require additional treatment or a change in your usage of your carbonic anhydrase inhibitor. You may experience gastrointestinal side effects such as stomach or abdominal pain, diarrhea, loss of appetite, nausea or nausea to the point of vomiting, vomiting blood, stomach cramps, or an unpleasant breath odor, or pale or light stools. Contact a doctor if you experience black, tarry, or bloody stools. You may experience urinary problems such as dark urine, a decreased volume of urine, increased thirst, dry mouth, pain in the lower side or back, difficult or painful urination, or yellow eyes or skin. You may experience confusion, dizziness, drowsiness, extreme fatigue, or a general feeling of weakness or tiredness, or mood changes. You may experience chills, or a fever with or without chills.

You may have respiratory problems such as chest pain or chest discomfort, a recurrent cough or hoarseness, deep or rapid breathing, irregular breathing, a sore throat, or tightness in the chest. You may experience dilated neck veins, an irregular heartbeat, muscle cramps or muscle pain, tingling or numbness in the extremities such as hands, feet, or lips, swelling of extremities such as the fingers, face, feet, or legs, joint or muscle pain, or headaches. You may experience restlessness, weight gain, unusual bruising or bleeding, glands that are swollen or painful, red or irritated eyes, or convulsions. You may experience a loosening, peeling, or blistering of the skin, itching or a rash, red skin lesions that may have a purple center, or sores, ulcers, or white spots on the lips or in the mouth. You may experience unusual weight gain. If you notice these symptoms occurring while you take your carbonic anhydrase inhibitor, contact your doctor immediately for directions.

While taking carbonic anhydrase inhibitors, you may experience symptoms of dichlorphenamide overdose. These side effects can include problems with elimination, such as bloody or cloudy urine, urination that is difficult or painful, a sudden decrease in the amount of urine you pass, or stools that are black, tarry, or bloody. You may experience a continuing ringing, buzzing, or other noise in the ears or some loss of hearing. You may experience a feeling of burning, itching, crawling, prickling, tingling, pins and needles, or numbness on your skin, or notice pale skin. You may feel shakiness in the arms, hands, legs or feet, a feeling of unsteadiness, trembling, or other problems with coordination or muscle control, or an unsteady or shaky walk. You may also faint. If you experience any of these symptoms, get emergency help immediately for an overdose of dichlorphenamide.

Dosage

The dosage and schedule of your carbonic anhydrase inhibitor provided here is a standard dose suggested by the manufacturer. Your doctor may prescribe you a different dosage of your carbonic anhydrase inhibitor or instruct you to take your dose of your carbonic anhydrase inhibitor at different intervals than described here. Always take your carbonic anhydrase inhibitor exactly as described by your doctor. If you are unsure about your dosage or schedule of your carbonic anhydrase inhibitor, contact your doctor or pharmacist with any questions.

Patients taking acetazolamide for glaucoma should take one 500 mg extended-release capsule twice a day in the morning and evening, or one 250 mg tablet one to four times per day. If patients are using this medication for altitude sickness, a 500 mg dose one to two times per day or 250 mg dose two to four times per day should be taken. Patients taking dichlorphenamide for glaucoma should take a 25 mg or 50 mg tablet one to three times per day. Patients taking methazolamide for glaucoma should take one 50 to 100 mg tablet two or three times per day. Children under 18 or patients taking these medications for epilepsy will have dosages based on body weight and other factors.

Your carbonic anhydrase inhibitor may make you dizzy or drowsy after taking it. Until you know how your dose of your carbonic anhydrase inhibitor affects you, do not drive, operate heavy machinery, or make decisions that require deep thought after you take your dose of your carbonic anhydrase inhibitor.

Take each dose of your carbonic anhydrase inhibitor with a glass of water. Carbonic anhydrase inhibitors can cause stomach upset, so you may need to take your dose with a small meal. If stomach upset, nausea, or vomiting continues or gets worse if you take this medication with food, check with your doctor quickly.

Carbonic anhydrase inhibitors may cause an increase in the amount of urine passed or your frequency of urination. It is crucial that you take your medication at the same time each day and do not skip a dose so that your body will adjust; this should cause the frequent urination to lessen or stop. To keep these mild urinary symptoms from affecting your sleep, you should adhere to a specific schedule when taking your dose. If you take a single dose during the day, take it in the morning after your first meal of the day. If you take more than one dose per day, take the last dose of the day no later than 6 PM unless otherwise directed by your doctor. Ask your doctor for help planning your dose of your carbonic anhydrase inhibitor so that it will have a minimal effect on your sleep and other personal activities.

If you miss a dose of your carbonic anhydrase inhibitor, take it as quickly as possible. If it is nearly time for your next dose, skip the dose you missed and return to your normal dosage schedule. Do not take a double dose of this medication, or your risk of side effects may be increased.

Carbonic anhydrase inhibitors may be taken by a parenteral route in some cases. Parenteral carbonic anhydrase inhibitors are normally administered via the topical route. Topical carbonic anhydrase inhibitors are usually prescribed to pets such as cats and dogs, especially sick or elderly cats and dogs. This is because they carry a smaller risk and severity of side effects.

Major Drug Interactions

Like any drug or medication, your carbonic anhydrase inhibitor may have unwanted interactions with other medications or substances. Interactions with other drugs may change the way your medications work, making them less effective, or can increase your risk of side effects that can threaten your health. Keep a list of the medications, drugs, and supplements you are taking on a regular basis, whether they are prescribed to you or you are taken them over the counter. Your doctor or pharmacist should be able to identify any interactions with your carbonic anhydrase inhibitor that should be avoided. While on your carbonic anhydrase inhibitor, do not start any new medications, stop taking medications, or change the dosage of your medications without your doctor's approval.

Your carbonic anhydrase inhibitor may interact with memantine or methenamine.

Aspirin or aspirin-like drugs, such as any form of salicylates or salicylic acid, can cause serious side effects when taken in large doses with carbonic anhydrase inhibitors. Check the labels of any medication you take while on your carbonic anhydrase inhibitor to determine whether it contains aspirin or any form of salicylic acid. If your doctor has directed you to take a low dosage of aspirin per day as a regular regimen (dosages from 81 to 325 mg per day) in order to help prevent a stroke or heart attack, keep taking your daily dose unless your doctor recommends otherwise. Ask your pharmacist or doctor for more details and information on safely taking medication that may contain aspirin. before you start taking carbonic anhydrase inhibitors, tell your doctor if you are taking medications with cyclosporines such as Sandimmune, primidone such as Mysoline, diflunisal such as Dolobid, lithium such as Lithobid, Eskalith, etc., salsalate such as Disalcid, Salflex, or Salsitab, magnesium salicylates such as Doan's, Magan, or Mobidin, or other salicylates.

Warnings

Dizziness

Your carbonic anhydrase inhibitor can make you drowsy or dizzy after taking it. Avoid driving cars, operating heavy machinery, or performing any activity that requires an alert mind after you take your carbonic anhydrase inhibitor until you know how you react to it. Limit alcoholic beverages while you are taking carbonic anhydrase inhibitors. If your dizziness or drowsiness becomes seriously bothersome, talk to your doctor about remedies or dosage.

Kidney Stones

Some patients taking carbonic anhydrase inhibitors may experience kidney stones. Symptoms of kidney stones in the body include painful urination, chills or a fever, a persistent need to urinate or urination that is more frequent than usual, severe pain in the side and back, pain that radiates to the groin and lower abdomen, and urine that is brown, pink, red, cloudy, or foul-smelling. You may also experience nausea and vomiting. If you experience these symptoms, get medical help immediately.

Signs of Infection

Some patients taking carbonic anhydrase inhibitors may contract an infection during the course of treatment. Signs of an infection may include a sore throat that doesn't go away, a fever, or chills. You may also experience unusual bleeding or bruising, tremors or tingling in your hands or feet, pain in your groin or side, or a skin rash. If you experience any of these symptoms while taking your carbonic anhydrase inhibitor, get medical help immediately.

Sunlight

Patients taking carbonic anhydrase inhibitors may experience an increased sensitivity to sunlight in the eyes or on the skin. If you are taking carbonic anhydrase inhibitors, try to avoid direct exposure to sunlight. If exposure to sunlight cannot be avoided, wear protective clothing and use sunscreen on exposed parts of the body to prevent damage to the skin. Do not use tanning booths or sunlamps while you are taking your carbonic anhydrase inhibitor. Tell your doctor immediately if you get skin blisters or skin redness after sun, or if you get sunburned.

Diseases

Carbonic anhydrase inhibitors can react badly to some diseases. Before starting your carbonic anhydrase inhibitor, tell your doctor if you have a heart disease, liver disease such as cirrhosis, lung disease or breathing problems such as chronic obstructive pulmonary disease or emphysema, kidney disease, a disease that is hormonal in nature, or a disease that requires a regimen of aspirin therapy. If you have these diseases, your doctor may need to adjust your dosage, add special monitoring during treatment, or find a substitute for carbonic anhydrase inhibitors.

Allergic Reactions

Some patients may have an extreme allergic reaction to carbonic anhydrase inhibitors. An allergic reaction to carbonic anhydrase inhibitors can manifest as difficulty breathing or shortness of breath, skin hives or a skin rash, and swelling of the mucous membranes such as the lips, tongue, or face. If you experience any of these symptoms while taking carbonic anhydrase inhibitors, get emergency medical assistance immediately.

Pregnancy

It is not known whether carbonic anhydrase inhibitors can cause harm to an unborn baby, or whether it passes into breast milk. If you are pregnant, nursing a child, or could become pregnant during the course of treatment, talk to your doctor first.

Lab Tests

This medication may interfere with the mechanism of some lab tests, and can cause false test results in some lab tests. When you are taking carbonic anhydrase inhibitors, make sure your doctor and any lab personnel administrating your tests know that you are taking carbonic anhydrase inhibitors at the time of testing.

Storage

Carbonic anhydrase inhibitors should be kept out of the reach of children. Store carbonic anhydrase inhibitors at room temperature, and in its original container. Make sure your carbonic anhydrase inhibitor is stored away from excessive heat or moist conditions.

Summary

Carbonic anhydrase inhibitors are a diuretic and anti-convulsant used to treat glaucoma, airsickness, and epilepsy by reducing the amount of fluid produced in the eye, stabilizing the water pressure in the body. It is normally available in tablets of several different dosages, and is used in different dosages for different conditions. Take your carbonic anhydrase inhibitor regularly for best effect, and take with a meal to reduce stomach upset.

Your carbonic anhydrase inhibitor may produce some mild side effects such as diarrhea or constipation, nausea or vomiting, a loss in appetite or weight loss, a metallic taste in the mouth or loss of taste and smell, a general feeling of illness or discomfort, nervousness or irritability, or a general feeling of discomfort or illness. You also may experience numbness or tingling, dizziness or drowsiness, headaches, and an increased sensitivity of the eyes to sunlight. Check with your doctor if these symptoms worsen or persist.

Your carbonic anhydrase inhibitor may produce some more serious side effects. You may experience elimination problems such as bloody urine or dark urine, pain or burning while urinating, pale stools or stools that are bloody, black, or tarry, dryness of mouth or increased thirst, and yellow eyes or skin. You may experience mental depression, unusual weakness or tiredness, clumsiness, trembling, mood changes, or fever. You may experience hives, sores, or a skin rash, a sore throat, unusual bleeding or bruising, muscle pain or cramps, a weak pulse or irregular heartbeat, or vomiting. If you experience any of these symptoms, check with your doctor immediately. Seek medical assistance immediately if you experience trouble breathing or shortness of breath.

Resources
Last Reviewed:
December 25, 2017
Last Updated:
April 04, 2018