Dichlorphenamide is used to treat occasional paralysis (loss of movement) caused by high or low levels of potassium in your blood.

Dichlorphenamide may also be used for purposes not listed in this medication guide.

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Call your doctor at once if you have accidental falls while taking dichlorphenamide. Your dose may need to be changed.

You may need medical tests to help your doctor determine how long to treat you with dichlorphenamide.

Store at room temperature away from moisture and heat.

Usual Adult Dose for Primary Periodic Paralysis:

-Initial dose: 50 mg orally 2 times a day; the initial dose may be increased or decreased based on individual response, at weekly intervals (or sooner in case of adverse reaction)
-Maximum dose: 200 mg orally per day

Comment:
-Primary hyperkalemic periodic paralysis, primary hypokalemic periodic paralysis, and related variants are a heterogeneous group of conditions, for which the response to this drug may vary. Prescribers should evaluate patient response to this drug after 2 months of treatment to decide whether therapy should be continued.

Use: For the treatment of primary hyperkalemic periodic paralysis, primary hypokalemic periodic paralysis, and related variants.

You should not use dichlorphenamide if you are allergic to it, or if you have:

• severe breathing problems;

• liver disease;

• an allergy to sulfa drugs; or

• if you also take aspirin in high doses.

Tell your doctor if you have ever had:

• metabolic acidosis (high levels of acid in your blood); or

• an electrolyte imbalance (such as low levels of potassium or magnesium in your blood).

Avoid using dichlorphenamide if you are pregnant. Dichlorphenamide may cause metabolic acidosis, which could harm an unborn baby if you have this condition during pregnancy. Tell your doctor if you become pregnant while taking dichlorphenamide.

It may not be safe to breastfeed while using this medicine. Ask your doctor about any risk.

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include dizziness, drowsiness, vomiting, loss of appetite, tremors, loss of balance or coordination, or ringing in your ears.

dichlorphenamide may cause blurred vision and may impair your reactions. Avoid driving or hazardous activity until you know how this medicine will affect you.

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Dichlorphenamide may cause serious side effects. Call your doctor at once if you have:

• the first sign of any skin rash, no matter how mild;

• an accidental fall;

• worsening of your paralysis symptoms;

• low potassium level--leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling; or

• signs of too much acid in your blood--irregular heartbeats, feeling tired, loss of appetite, trouble thinking, feeling short of breath.

Accidental falls are more likely in older adults or in people who take high doses of Dichlorphenamide. Use caution to avoid falling or accidental injury while you are taking dichlorphenamide.

Common side effects of dichlorphenamide may include:

• drowsiness;

• confusion;

• numbness or tingling; or

• altered sense of taste.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your doctor about all your other medicines, especially:

• aspirin (including baby aspirin);

• famotidine;

• methotrexate;

• theophylline;

• an antibiotic or antifungal medicine;

• antiviral medicine such as oseltamivir;

• a laxative; or

• a diuretic or "water pill" such as furosemide.

This list is not complete. Other drugs may affect dichlorphenamide, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.