Dichlorphenamide
Dichlorphenamide is a carbonic anhydrase inhibitor used to reduce the frequency of paralytic attacks in patients with primary periodic paralysis, a rare genetic muscle disorder. Originally developed for glaucoma treatment, it helps manage this chronic condition that causes episodes of muscle weakness or paralysis. The medication works by altering electrolyte balance in the body, though its precise mechanism in periodic paralysis is not fully understood.
Dichlorphenamide is a carbonic anhydrase inhibitor prescribed to reduce attack frequency in primary periodic paralysis, a rare genetic muscle disorder.
Key facts at a glance
- ATC
- S01EC02
- RxNorm
- 3353
- Generic
- Dichlorphenamide
- Class
- atc-s01
- Brands
- Keveyis, Ormalvi
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- tablet
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dichlorphenamide is indicated for the treatment of primary periodic paralysis, including hypokalemic periodic paralysis, hyperkalemic periodic paralysis, and related variants. These are rare genetic disorders characterized by recurrent episodes of muscle weakness or paralysis. The medication is also used for glaucoma and ocular hypertension in some formulations.
Dichlorphenamide inhibits carbonic anhydrase, an enzyme involved in electrolyte balance and fluid secretion. While its exact mechanism in periodic paralysis is unknown, it is believed to help stabilize muscle membrane excitability and reduce the frequency of paralytic attacks by influencing potassium levels and acid-base balance in the body.
Common side effects include paresthesia (tingling), drowsiness, and GI disturbances. The medication can cause metabolic acidosis and hypokalemia, requiring periodic monitoring of blood electrolytes. Patients with hepatic or renal impairment should use with caution. May interact with other carbonic anhydrase inhibitors, aspirin, or diuretics. Not recommended during pregnancy without careful risk assessment.
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy