Dosing and uses of Keveyis (dichlorphenamide)
Adult dosage forms and strengths
tablet
- 50mg
Periodic Paralysis
Indicated for primary hyperkalemic periodic paralysis, primary hypokalemic periodic paralysis, and related variants
50 mg PO q12hr; increase or decrease at weekly intervals according to individual response; not to exceed 200 mg/day
Evaluate patient response after 2 months of treatment to decide drug should be continued
Pediatric dosage forms and strengths
Safety and efficacy not established
Geriatric dosage forms and strengths
Periodic Paralysis
Indicated for primary hyperkalemic periodic paralysis, primary hypokalemic periodic paralysis, and related variants
50 mg PO q12hr; increase or decrease at weekly intervals according to individual response; not to exceed 200 mg/day
Evaluate patient response after 2 months of treatment to decide whether drug should be continued
Use lowest effective dose possible, owing to risk increased risk of falls
Keveyis (dichlorphenamide) adverse (side) effects
>10%
Paresthesia (44%)
Cognitive disorder (14%)
Dysgeusia (14%)
Confusional state (11%)
1-10%
Headache (8%)
Hypoesthesia (8%)
Lethargy (8%)
Fatigue (8%)
Muscle spasms (8%)
Rash (8%)
Dizziness (6%)
Diarrhea (6%)
Nausea (6%)
Malaise (6%)
Decreased weight (6%)
Arthralgia (6%)
Muscle twitching (6%)
Dyspnea (6%)
Pharyngolaryngeal pain (6%)
Pruritus (6%)
Postmarketing Reports
Amnesia
Cardiac failure
Convulsion
Fetal death
Hallucination
Nephrolithiasis
Pancytopenia
Psychotic disorder
Renal tubular necrosis
Stupor
Syncope
Tremor
Warnings
Contraindications
Hypersensitivity to dichlorphenamide or other sulfonamides
Coadministration with high-dose aspirin
Severe pulmonary disease, limiting compensation to metabolic acidosis caused by dichlorphenamide
Hepatic insufficiency; dichlorphenamide may aggravate hepatic encephalopathy
Cautions
Fatalities associated with sulfonamides reported; hypersensitivity, anaphylaxis, and idiosyncratic reactions reported and may include Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia, and other blood dyscrasias; pulmonary symptoms may occur in isolation or as part of a systemic reaction; discontinue at first sign of rash
Coadministration with high-dose aspirin may result in anorexia, tachypnea, lethargy, and coma (also see Contraindications)
Hypokalemia reported; monitor potassium levels periodically; risk is greater when dichlorphenamide is used with conditions associated with hypokalemia (eg, adrenocortical insufficiency, hyperchloremic metabolic acidosis, respiratory acidosis) and in patients receiving other drugs that may cause hypokalemia (eg, loop diuretics, thiazide diuretics, laxatives, antifungals, penicillin, theophylline)
Can cause hyperchloremic nonanion gap metabolic acidosis; coadministration with other drugs that cause metabolic acidosis may increase the severity; measure bicarbonate at baseline and then periodically; if metabolic acidosis develops or persists, consider reducing dose or discontinuing the drug
Increased risk of falls; risk is greater in elderly patients and with higher doses
Pregnancy and lactation
Pregnancy
Pregnancy category: C
Lactation
Unknown if distributed in human breast milk
Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for the drug and any potential adverse effects on the breastfed infant from the drug or from the underlying maternal condition
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Keveyis (dichlorphenamide)
Mechanism of action
Carbonic anhydrase inhibitor, but the exact mechanism by which dichlorphenamide is able to treat periodic paralysis is unknown
Dichlorphenamide helps to normalize blood-potassium levels by decreasing levels
