Home Drug Guide Diphenidol Hydrochloride

Drug Guide

Generic Name

Diphenidol Hydrochloride

Brand Names Vontrol

Classification

Therapeutic: Anti-vertigo, Antiemetic

Pharmacological: Anticholinergic, Antihistaminic

FDA Approved Indications

  • Vertigo associated with Meniere's disease
  • Nausea and vomiting

Mechanism of Action

Diphenidol acts centrally to block vestibular afferent pathways and has anticholinergic and antihistaminic properties, which help reduce nausea, vomiting, and vertigo.

Dosage and Administration

Adult: Typically 50-75 mg 3 times daily, or as directed by a physician; dosage adjustments may be needed based on response.

Pediatric: Use is generally not recommended for children due to limited data.

Geriatric: Start at lower doses due to increased sensitivity and potential for adverse effects; monitor closely.

Renal Impairment: Adjust dose based on renal function, if necessary.

Hepatic Impairment: Use with caution; monitor liver function.

Pharmacokinetics

Absorption: Well absorbed orally.

Distribution: Widely distributed in body tissues.

Metabolism: Metabolized in the liver.

Excretion: Excreted primarily in urine and feces.

Half Life: Approximately 4-6 hours.

Contraindications

  • Hypersensitivity to diphenidol or other components.
  • Narrow-angle glaucoma.
  • Present or past history of prostatic hypertrophy with urinary retention.

Precautions

  • Use cautiously in patients with liver or kidney impairment.
  • May cause drowsiness; caution when driving or operating machinery.
  • Pregnancy and lactation: consult healthcare provider before use.

Adverse Reactions - Common

  • Drowsiness (Common)
  • Dry mouth (Common)
  • Dizziness (Common)

Adverse Reactions - Serious

  • Urinary retention (Rare)
  • Blurred vision (Rare)
  • Hypersensitivity reactions (Rare)

Drug-Drug Interactions

  • Additive CNS depression with other sedatives, alcohol, or hypnotics.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor for therapeutic effectiveness and adverse effects such as drowsiness, dry mouth, urinary retention.

Diagnoses:

  • Risk for falls related to dizziness or drowsiness.
  • Impaired urinary elimination.

Implementation: Administer with meals if gastrointestinal upset occurs; avoid operating heavy machinery until response is known.

Evaluation: Assess reduction in vertigo and nausea, monitor adverse effects.

Patient/Family Teaching

  • Take medication exactly as prescribed.
  • Avoid alcohol and CNS depressants.
  • Report any signs of urinary retention, severe dizziness, or allergic reactions.
  • Do not operate heavy machinery until sedative effects are known.

Special Considerations

Black Box Warnings:

  • None

Genetic Factors: None identified.

Lab Test Interference: None known.

Overdose Management

Signs/Symptoms: Severe anticholinergic effects such as dry mouth, dilated pupils, hallucinations, urinary retention, tachycardia, confusion.

Treatment: Supportive care; no specific antidote. Activated charcoal may be used if ingestion was recent; symptom management includes cooling measures for hyperthermia and IV fluids.

Storage and Handling

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

Stability: Stable under recommended storage conditions.

🛡️ 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.