Home Drug Guide Dichlorphenamide

Drug Guide

Generic Name

Dichlorphenamide

Brand Names Daranide, Keveyis, Ormalvi

Classification

Therapeutic: Anticonvulsant, Carbonic Anhydrase Inhibitor

Pharmacological: Carbonic Anhydrase Inhibitor

FDA Approved Indications

  • Primary hyperkalemic periodic paralysis
  • Primary hypokalemic periodic paralysis
  • Andersen-Tawil syndrome

Mechanism of Action

Dichlorphenamide inhibits carbonic anhydrase enzymes, leading to decreased hydrogen ion secretion in renal tubules, which in turn alters ion transport and stabilizes muscle cell membranes, reducing episodes of paralysis.

Dosage and Administration

Adult: Typically 50-100 mg orally once or twice daily, adjusted based on response and tolerability.

Pediatric: Not generally recommended due to limited data; consult specialist.

Geriatric: Start at lower doses with careful monitoring due to increased risk of side effects.

Renal Impairment: Use with caution; adjust dose as necessary, considering renal function.

Hepatic Impairment: Use with caution; no specific dosage adjustment established.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed, crosses blood-brain barrier.

Metabolism: Minimal hepatic metabolism.

Excretion: Primarily renal excretion of unchanged drug.

Half Life: Approximately 2-4 hours.

Contraindications

  • Known hypersensitivity to dichlorphenamide or sulfonamides.

Precautions

  • Monitor for sulfa allergies.
  • Use with caution in patients with renal or hepatic impairment.
  • Monitor serum electrolytes regularly.
  • May cause metabolic acidosis; monitor acid-base status.

Adverse Reactions - Common

  • Paresthesia (Common)
  • Dizziness (Common)
  • Gastrointestinal upset (Common)

Adverse Reactions - Serious

  • Metabolic acidosis (Rare)
  • Electrolyte disturbances (hypokalemia, hyponatremia) (Rare)
  • Acute myopia and secondary glaucoma (Rare)

Drug-Drug Interactions

  • Other carbonic anhydrase inhibitors, digoxin (risk of toxicity), corticosteroids (altered electrolyte balance)

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor serum electrolytes, renal function, and acid-base status regularly. Evaluate muscle strength and frequency of paralysis episodes.

Diagnoses:

  • Risk for electrolyte imbalance
  • Risk for impaired renal function

Implementation: Administer with food if GI upset occurs. Encourage hydration. Educate patient on adherence and monitoring requirements.

Evaluation: Assess frequency of paralysis episodes, electrolyte levels, and side effects periodically.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Report signs of electrolyte imbalance, visual changes, or new neurological symptoms.
  • Maintain hydration.
  • Avoid abrupt discontinuation.

Special Considerations

Black Box Warnings:

  • None currently.

Genetic Factors: No specific genetic markers influence response or risk.

Lab Test Interference: May affect serum electrolyte and acid-base measurements.

Overdose Management

Signs/Symptoms: Severe metabolic acidosis, electrolyte disturbances, CNS depression.

Treatment: Supportive care, correction of electrolyte imbalances, alkalinization if necessary. Hemodialysis in severe cases.

Storage and Handling

Storage: Store at room temperature, away from moisture and light.

Stability: Stable when stored properly, check expiration date.

🛡️ 5 Critical Medication Safety Tips for Nurses

1

Triple-Check High-Risk Medications

Always have another nurse verify insulin, heparin, warfarin, and chemotherapy drugs. These "high-alert" medications cause the most serious errors. Check concentration, dose calculation, and pump settings twice.

2

Know Look-Alike, Sound-Alike Drugs

Common mix-ups: hydromorphone/morphine, Celebrex/Celexa, Zyprexa/Zyrtec. Always use BOTH generic and brand names, read labels twice, and use barcode scanning when available. One wrong letter can be fatal.

3

Assess Before AND After Giving Meds

Check vitals before cardiac meds, pain levels before analgesics, and blood glucose before insulin. Always reassess within 30 minutes to evaluate effectiveness and watch for adverse reactions.

4

Watch for Drug Interactions

Common dangerous combinations: warfarin + aspirin (bleeding), ACE inhibitors + potassium (hyperkalemia), digoxin + diuretics (toxicity). Always check drug interactions before administering new medications.

5

Educate Your Patients

Teach patients medication names, purposes, major side effects, and what to report. Informed patients catch errors and improve compliance. Always encourage questions - an educated patient is a safer patient.

⚡ Remember: When in doubt, don't give it out! It's always safer to double-check than regret later.

⚠️ Medical Disclaimer

This drug guide is for educational purposes only and is NOT intended for clinical use. Always consult current prescribing information, healthcare providers, and institutional protocols before administering any medication. Do not use this information for patient care decisions.