Usage
Dibucaine is a local anesthetic used to relieve pain and itching caused by minor skin irritations such as sunburn, minor burns, cuts, scrapes, insect bites, and hemorrhoids. It belongs to the amide class of local anesthetics. Dibucaine works by reversibly blocking nerve conduction, preventing the transmission of pain signals from the affected area to the brain.
Alternate Names
Dibucaine is also known as cinchocaine. Brand names include Nupercainal and Rectacaine.
How It Works
Pharmacodynamics: Dibucaine acts by inhibiting sodium channels in nerve cell membranes. This blockage prevents the depolarization of the nerve, effectively stopping the transmission of pain signals.
Pharmacokinetics: Dibucaine is applied topically and is minimally absorbed into the systemic circulation. When used as directed, blood levels remain low, minimizing systemic effects. The limited absorbed drug is metabolized in the liver and excreted via the kidneys. The specific CYP enzymes involved in its metabolism are not well characterized.
Dosage
Dibucaine is available as a 10% ointment for topical application.
Standard Dosage
Adults:
Apply a thin layer to the affected area 3 to 4 times daily. Do not exceed 30 grams in a 24-hour period.
Children:
- 2 years and older: Apply a thin layer to the affected area 3 to 4 times daily. Do not exceed 7.5 grams in a 24-hour period.
- Under 2 years: Safety and efficacy have not been established. Consult a pediatrician before use.
Special Cases:
- Elderly Patients: Use with caution. Dose reduction may be necessary due to potential age-related decrease in metabolic function and organ function.
- Patients with Renal Impairment: Use with caution. Dosage adjustment may be necessary depending on the degree of impairment.
- Patients with Hepatic Dysfunction: Use with caution. Monitor for signs of liver toxicity. Dosage adjustment may be needed.
- Patients with Comorbid Conditions: Caution is advised. Individualized dosing considerations may be necessary depending on the specific comorbidity.
Clinical Use Cases:
Dibucaine is generally not indicated for clinical use cases such as intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations. Its primary use is limited to the topical treatment of minor skin conditions. For these procedures, other local anesthetics with better safety and efficacy profiles are generally preferred.
Dosage Adjustments
Dosage adjustments may be required in patients with renal or hepatic impairment, or other conditions that could affect drug metabolism. Consult a healthcare professional for guidance.
Side Effects
Common Side Effects
- Contact dermatitis
- Photosensitivity
- Flushing
- Eye/skin irritation
Rare but Serious Side Effects
- Allergic reactions (e.g., rash, itching, swelling, difficulty breathing)
- Methemoglobinemia (a blood disorder)
Long-Term Effects
Chronic use is not recommended due to potential skin sensitization.
Adverse Drug Reactions (ADR)
Severe allergic reactions and methemoglobinemia are serious ADRs requiring urgent medical attention.
Contraindications
- Hypersensitivity to dibucaine or other amide-type local anesthetics.
- Open wounds, broken, or infected skin in the area of application.
Drug Interactions
No severe drug interactions have been formally reported with topical dibucaine. However, concurrent use with other topical medications on the same area should be avoided unless directed by a physician. Medications associated with methemoglobinemia should be used with caution.
Pregnancy and Breastfeeding
- Pregnancy: Pregnancy Category C. Use only if clearly needed and after careful consideration of risks and benefits.
- Breastfeeding: Use with caution. It is unknown if dibucaine is excreted in breast milk. Avoid applying to the nipple area to prevent infant ingestion.
Drug Profile Summary
- Mechanism of Action: Blocks nerve conduction by inhibiting sodium channels.
- Side Effects: Contact dermatitis, photosensitivity, flushing, eye/skin irritation. Rarely: allergic reactions, methemoglobinemia.
- Contraindications: Hypersensitivity, application to open wounds or infected skin.
- Drug Interactions: No severe interactions reported. Use with caution with methemoglobinemia-inducing agents.
- Pregnancy & Breastfeeding: Use with caution in both.
- Dosage: Topical application 3-4 times daily. Adults: Max 30g/day. Children 2+ years: Max 7.5g/day.
- Monitoring Parameters: Observe for local skin reactions and signs of allergic reactions or methemoglobinemia.
Popular Combinations
Topical dibucaine is typically used alone. No established popular combinations exist.
Precautions
- General Precautions: Discontinue use if irritation develops. Avoid contact with eyes, nose, and mouth.
- Specific Populations: As outlined in the Dosage section.
- Lifestyle Considerations: Avoid excessive sun exposure.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Dibucaine?
A: Adults: Apply thinly 3-4 times daily, not exceeding 30g/day. Children 2+ years: Apply thinly 3-4 times daily, not exceeding 7.5g/day. Not recommended for children under 2 years.
Q2: What are the primary uses of Dibucaine?
A: Primarily used to relieve pain and itching associated with minor skin irritations like sunburn, minor burns, cuts, and hemorrhoids.
Q3: How does Dibucaine work?
A: Acts as a local anesthetic by blocking nerve conduction, thus preventing pain signals from reaching the brain.
Q4: What are the common side effects of Dibucaine?
A: Contact dermatitis, photosensitivity, flushing, and skin/eye irritation.
Q5: Are there any serious side effects I should be aware of?
A: Rarely, allergic reactions or methemoglobinemia can occur. Seek immediate medical attention if these occur.
Q6: Can Dibucaine be used during pregnancy or breastfeeding?
A: Use with caution during both pregnancy and breastfeeding, and only if the benefits outweigh the risks. Consult a healthcare professional for guidance.
Q7: Are there any drug interactions with Dibucaine?
A: No major drug interactions have been reported, but caution is advised when using medications associated with methemoglobinemia. Avoid applying other topical medications to the same area without consulting a doctor.
Q8: What should I do if I experience side effects while using Dibucaine?
A: Discontinue use and consult a healthcare professional. If experiencing serious side effects like allergic reaction or methemoglobinemia, seek immediate medical attention.
Q9: Can Dibucaine be used on open wounds?
A: No, Dibucaine should not be used on open wounds, broken, or infected skin.
Q10: How should Dibucaine be stored?
A: Store at room temperature away from excessive heat and light. Keep the tube tightly closed when not in use.
