Cinchocaine

Usage

Cinchocaine is a local anesthetic, primarily used to provide temporary relief from pain and itching associated with minor skin irritations such as burns (including sunburn), cuts, abrasions, insect bites, and hemorrhoids. It is also prescribed for anorectal conditions like anal fissures. It can be found in some ear drop solutions. It’s pharmacological classification is local anesthetic.

Cinchocaine’s mechanism of action involves blocking nerve impulse conduction by decreasing cell membrane permeability to sodium ions. This action prevents pain signals from reaching the brain.

Alternate Names

Cinchocaine is also known as Dibucaine. Brand names include Nupercainal, Nupercaine, Sovcaine, Proctosedyl (often in combination with other medications like hydrocortisone), Faktu (with policresulen), and Scheriproct (with prednisolone).

How It Works

Pharmacodynamics: Cinchocaine’s primary effect is to induce local anesthesia by stabilizing neuronal membranes and inhibiting sodium influx, thus preventing depolarization and nerve impulse propagation. The duration of action is typically 2-4 hours.

Pharmacokinetics: When applied topically, absorption through intact skin is minimal, especially for the ionized salt forms. However, absorption is increased through broken or inflamed skin. Cinchocaine is primarily metabolized in the liver. Elimination pathways are not well documented, however, limited systemic absorption suggests renal and hepatic excretion of metabolites.

Mode of Action: Cinchocaine binds to voltage-gated sodium channels in nerve cell membranes, blocking the influx of sodium ions required for nerve impulse transmission. This results in a localized loss of sensation, including pain and itching.

Receptor Binding/Enzyme Inhibition/Neurotransmitter Modulation: Cinchocaine’s main mechanism involves the reversible binding to sodium channels, rather than enzyme inhibition or neurotransmitter modulation.

Dosage

Standard Dosage

Adults: As a 0.5% ointment or cream: Apply a small amount to the affected area 3-4 times daily, not exceeding 30g in a 24-hour period. As a suppository (5mg): Insert one suppository in the rectum twice a day (morning and evening) and after each bowel movement for up to 7 days.

Children: For children 2 years and older, use the ointment 3-4 times a day, not exceeding 7.5g in 24 hours. Use in children under 2 years of age is not generally recommended, and should only be done under the guidance of a pediatrician.

Special Cases:

• Elderly Patients: Use with caution due to potential for increased systemic absorption and sensitivity.
• Patients with Renal Impairment: Caution is advised due to potential accumulation of metabolites. Dose adjustments may be necessary.
• Patients with Hepatic Dysfunction: Metabolism may be impaired, so dose adjustments might be needed.
• Patients with Comorbid Conditions: Cinchocaine interacts with certain medications, like antiarrhythmics. Careful consideration is necessary for those with heart conditions.

Clinical Use Cases

Cinchocaine is generally not indicated for clinical procedures like intubation, surgical procedures, mechanical ventilation, or ICU use where deeper and more controlled anesthesia is required. It is not typically used in emergency situations. Its use is restricted to minor, topical anesthesia.

Dosage Adjustments

Adjustments are required based on patient factors like renal or hepatic impairment and age. Drug interactions also necessitate dose modifications.

Side Effects

Common Side Effects

Localized reactions such as burning, itching, irritation, redness, and contact dermatitis at the application site. These are generally mild and transient.

Rare but Serious Side Effects

Allergic reactions (rash, hives, swelling, difficulty breathing), systemic toxicity (dizziness, headache, confusion, seizures, cardiac arrhythmias), and methemoglobinemia (cyanosis, shortness of breath, fatigue).

Long-Term Effects

Skin atrophy or thinning with prolonged topical corticosteroid use (when cinchocaine is in combination products), potential for skin sensitization and increased risk of infection.

Adverse Drug Reactions (ADR)

Allergic reactions, systemic toxicity, and methemoglobinemia necessitate immediate medical intervention.

Contraindications

Hypersensitivity to cinchocaine or other amide local anesthetics, infected or broken skin, pyogenic infections near the application site, certain types of skin infections, severe burns, and use near eyes, nose, or mouth. In combination preparations containing hydrocortisone: tuberculosis, viral lesions (herpes simplex, chicken pox).

Drug Interactions

Other local anesthetics (additive toxicity), certain antiarrhythmics (increased risk of cardiac side effects), muscle relaxants and other anesthetic agents (prolonged muscle weakness, respiratory depression), anticoagulants (increased bleeding risk), CYP3A4 inhibitors (ritonavir, cobicistat) - increased risk of systemic side effects including adrenal suppression, and drugs metabolized by the liver (potential for altered metabolism of Cinchocaine).

Pregnancy and Breastfeeding

Consult individual product information for combined formulations. Cinchocaine as a single ingredient is not recommended for routine use during pregnancy and breastfeeding. Topical application carries a minimal risk of fetal exposure, but should be used cautiously and only when the benefits outweigh the risks.

Drug Profile Summary

• Mechanism of Action: Blocks nerve impulse conduction by inhibiting sodium influx into nerve cells.
• Side Effects: Localized irritation, allergic reactions, systemic toxicity, methemoglobinemia.
• Contraindications: Hypersensitivity, infected skin, severe burns, use near eyes/nose/mouth.
• Drug Interactions: Other local anesthetics, antiarrhythmics, muscle relaxants, anticoagulants, CYP3A4 inhibitors, some hepatic metabolized drugs.
• Pregnancy & Breastfeeding: Caution advised, use only when benefit outweighs risk.
• Dosage: Varies by formulation and indication, generally applied topically several times daily or as suppositories.
• Monitoring Parameters: Observe application site for irritation or allergic reactions, monitor for signs of systemic toxicity.

Popular Combinations

Hydrocortisone (anti-inflammatory), prednisolone (anti-inflammatory), policresulen (tissue regenerating agent), neomycin (antibiotic), esculin (venotonic, strengthens capillaries).

Precautions

• General Precautions: Avoid use on broken or infected skin, avoid contact with eyes/nose/mouth, assess patient for allergies, hepatic or renal impairment.
• Specific Populations:
  • Pregnant Women: Use with caution, consult product information for combination preparations.
  • Breastfeeding Mothers: Use with caution, consult product information for combination preparations.
  • Children & Elderly: Use with caution in children, especially under 2 years. Elderly may be more sensitive.
• Lifestyle Considerations: Alcohol consumption might worsen potential side effects. Driving is generally unaffected unless systemic absorption occurs and causes dizziness.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Cinchocaine?

A: The dosage varies depending on the formulation and indication. Consult the specific product information and individual patient factors. As a general guideline, topical ointment can be used 3-4 times daily, not exceeding 30g for adults or 7.5g for children 2 years and older in a 24 hour period. Suppositories are typically used twice a day and after each bowel movement, for a maximum of 7 days.

Q2: What are the primary uses of Cinchocaine?

A: Cinchocaine is primarily used to relieve pain and itching associated with minor burns, cuts, abrasions, insect bites, hemorrhoids, and anal fissures.

Q3: Can Cinchocaine be used during pregnancy or breastfeeding?

A: It’s generally advised to avoid routine use during pregnancy and breastfeeding. Use with caution and only when the benefits outweigh the risks. Consult product information and your healthcare provider.

Q4: What are the potential side effects of Cinchocaine?

A: Common side effects are localized reactions like burning or itching at the application site. Rare but serious side effects include allergic reactions, systemic toxicity, and methemoglobinemia.

Q5: What are the contraindications for Cinchocaine use?

A: Contraindications include hypersensitivity, application to broken or infected skin, severe burns, proximity to eyes/nose/mouth. Combined preparations containing hydrocortisone have additional contraindications like tuberculosis and viral lesions.

Q6: Does Cinchocaine interact with other medications?

A: Yes, Cinchocaine can interact with other local anesthetics, antiarrhythmics, muscle relaxants, anticoagulants, CYP3A4 inhibitors, and some drugs metabolized by the liver.

Q7: How does Cinchocaine work?

A: Cinchocaine blocks nerve impulse conduction by reversibly binding to voltage-gated sodium channels, preventing sodium influx into nerve cells. This prevents pain signals from being transmitted.

Q8: What should patients know before using Cinchocaine?

A: Patients should inform their doctor about any allergies or other medical conditions, especially liver or kidney disease. They should also avoid using Cinchocaine on broken or infected skin and avoid contact with eyes/nose/mouth.

Q9: What is the difference between Cinchocaine cream and Cinchocaine suppositories?

A: Cinchocaine cream is used for topical application on external skin irritations, while suppositories are designed for insertion into the rectum to treat hemorrhoids and other anorectal conditions.

Q10: How long does the anesthetic effect of Cinchocaine last?

A: The anesthetic effect typically lasts for 2-4 hours.