Drug information of dichlorphenamide


Drug group:

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

Mechanism of effect

Dichlorphenamide is a carbonic anhydrase inhibitor; the mechanism by which dichlorphenamide exerts its therapeutic effects in patients with periodic paralysis is unknown


Time to Peak
 to 3 hours
Half-Life Elimination
Terminal: 32 to 66 hours

Drug indications

Primary periodic paralysis: Treatment of primary hyperkalemic periodic paralysis, primary hypokalemic periodic paralysis, and related variants


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

Drug contraindications

Hypersensitivity to dichlorphenamide, other sulfonamides, or any component of the formulation; concomitant use with high-dose aspirin; severe pulmonary disease; hepatic insufficiency

Side effects

Central nervous system: Paresthesia, cognitive dysfunction, confusion
Gastrointestinal: Dysgeusia
 to 10%
Central nervous system: Fatigue, headache, hypoesthesia, lethargy, dizziness, malaise
Dermatologic: Skin rash, pruritus
Endocrine & metabolic: Weight loss
Gastrointestinal: Diarrhea, nausea
Neuromuscular & skeletal: Muscle spasm, arthralgia, muscle twitching
Respiratory: Dyspnea, pharyngolaryngeal pain
Frequency not defined: Central nervous system: Difficulty thinking, disturbance in attention
Postmarketing: Amnesia, cardiac failure, hallucination, increased severity of condition, nephrolithiasis, pancytopenia, psychosis, renal tubular necrosis, seizure, stupor, syncope, tremor

Alpha-/Beta-Agonists (Indirect-Acting), Amantadine, Amphetamines, Amphotericin B,
Antifungal Agents (Azole Derivatives, Systemic), CarBAMazepine, Carbonic Anhydrase Inhibitors, Diacerein, Famotidine, Flecainide, Fosphenytoin-Phenytoin, Laxatives, Lithium,
Loop Diuretics, Memantine, MetFORMIN, Methenamine, Methotrexate, OAT1/3 Inhibitors,
Opioid Agonists, Oseltamivir, Penicillins, Primidone, QuiNIDine, Salicylates, Sodium Phosphates,
Theophylline, Thiazide and Thiazide-Like Diuretics, Trientine


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

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

Safety and efficacy have not been established in patients younger than 18 years

May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (eg, operating machinery or driving

Dichlorphenamide increases potassium excretion and may cause hypokalemia; risk is increased in patients with a history of conditions associated with hypokalemia (eg, adrenocortical excess, renal tubular acidosis type 1 and 2) and coadministration with medications associated with hypokalemia (eg, loop diuretics, thiazide diuretics, laxative, antifungals, penicillin, theophylline). Monitor serum potassium at baseline and periodically throughout treatment; discontinue use or reduce the dose if hypokalemia develops or persists and correct potassium levels

Points of recommendation

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

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

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

Pregnancy level

Data are not available on the developmental risk associated with the use in pregnant women

Breast feeding warning

Unknown if distributed in human breast milk

Drug forms

Keveyis, Daranide

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