Acetazolamide in Idiopathic Intracranial Hypertension

Summary: Idiopathic Intracranial Hypertension (IIH) • Increased intracranial pressure of an idiopathic nature • Treated with acetazolamide/weight loss + surgery as deemed necessary o Acetazolamide (Diamox) is an effective first-line therapy according to IIH Treatment Trial (IIHTT) -Lowers intracranial pressure -Treats vision loss and papilledema stemming from IIH IIH Patients and Treatment • Tend to be young, overweight females o Weight loss is preferred treatment • Acetazolamide is effective medical therapy o Normal dosage is 500 mg a day -IIHTT allows for dosage of up to 2-4 grams/day o Dosage limited by side effects -Paresthesias -Tingling in hands/feet -Metallic taste in mouth following consumption of carbonated beverages -Fatigue -Frequent urination is a known side effect, but a rare complaint from IIH patients treated with acetazolamide Metabolic Acidosis due to Acetazolamide Treatment • Acetazolamide is a carbonic anhydrase inhibitor o Removes water from carbonic acid o Generates water and carbon dioxide -Water and carbon dioxide are easily removed from body -good byproducts • Carbonic anhydrase inhibition prevents build of these good byproducts o Carbonic acid will subsequently dissociate into hydrogen and bicarbonate ions -Kidney pushes bicarb into urine -alkylurea + metabolic acidosis • Na+/H+ exchangers and Na+/K+ pumps result in potassium being pushed into urine HYPOkalemia (life threatening) • Chloride/bicarbonate exchanger impacted due to dumping of bicarbonate into urine HYPERchloremia (life threatening and causes patient discomfort) •Hypokalemic hyperchloremic metabolic acidosis o Acetazolamide contraindicated for patients without IIH or with metabolic acidosis due to potentially life-threatening electrolyte imbalances Cryptococcal Meningitis • Cryptococcal meningitis results in non-idiopathic intracranial hypertension o Acetazolamide administration during clinical trials for cryptococcal meningitis patients resulted in adverse outcomes (death) • Serial lumbar puncture or lumbar drain used to relieve intracranial pressure instead of acetazolamide for cryptococcal meningitis patients [Questions] Any thoughts on other medications to treat Diamox, such as methazolamide, and their effectiveness? • Methazolamide can effectively substitute for Diamox when the side-effects of Diamox are intolerable. Other suggested medications for effective treatment of IIH include Topiramate and Furosemide. I have just been diagnosed with IIH and have been taking Diamox - does it cause severe stomach pain? • Stomach pain is a potential side effect of Diamox treatment. It is recommended to take Diamox with a meal in order to prevent stomach discomfort. Can you develop the kidney problems if the dose is too high? I take 1000 mg at night and have for 5 years. I have lost weight and dose has not been adjusted since. I am having a lot of kidney issues, even stones. • High dosages of Diamox can lead to problems with the kidney. It is important to talk with your provider about severe side effects in order to evaluate the benefits of treatment. Would it be beneficial to take a potassium vitamin along with acetazolamide to prevent any issues? • Potassium supplements are often used to treat low potassium levels caused by acetazolamide. Talk with your doctor to determine if a potassium supplement is recommended in your treatment plan