Lidocaine for piles and itchy bottom

Generic Name: Lidocaine (topical, rectal use)
Drug Class: Local anesthetic (amide type)
Pharmacological Class: Sodium channel blocker
ATC Code: C05AD01 (for anorectal use)
Common Brand Names: Anusol Plus HC, Lidocaine Ointment, Recticare, Nupercainal, Anusol-Lido, Scheriproct (with corticosteroids)

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Mechanism of Action

Lidocaine acts as a local anesthetic by reversibly inhibiting voltage-gated sodium channels in neuronal membranes of peripheral nerves. This:

• Blocks the initiation and propagation of action potentials

• Provides temporary numbness and relief from pain, burning, and itching associated with piles (hemorrhoids) or anal irritation

When applied rectally, lidocaine does not treat the underlying inflammation or cause of hemorrhoids, but it alleviates symptomatic discomfort by reducing pain transmission from irritated perianal tissue.

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Therapeutic Indications

Topical lidocaine creams or ointments are indicated for:

1. Relief of Pain, Irritation, and Itching Associated With:

   • Hemorrhoids (internal and external)

   • Anal fissures

   • Proctitis and anal pruritus (itchy bottom)

   • Postoperative anorectal procedures (e.g., after hemorrhoidectomy)

2. Pre-anorectal Procedures (off-label use):

   • Applied before digital rectal examination or anoscopy to reduce discomfort

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Formulations and Strengths

• Ointments/Creams: Lidocaine 5% (typical for rectal use)

• Gel Formulations: 2–5% lidocaine gel for local application

• Combination Products:

  • Lidocaine + Hydrocortisone (e.g., Anusol Plus HC): For additional anti-inflammatory effects

  • Lidocaine + Zinc oxide, or antiseptics: To protect and soothe the mucosa

Dosage Form Specifics:

• Available as rectal ointments, creams, or suppositories (with or without steroids)

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Dosage and Administration

Adults and Adolescents ≥12 Years:

• Apply a small amount (pea-sized, about 0.5–1 g) of 5% lidocaine ointment directly to the affected area up to 3–4 times daily

• Can be applied before and after defecation for symptom relief

• In severe cases, may apply just inside the anal canal using a finger cot or applicator (do not insert deep inside)

Children (<12 years):

• Use only under medical supervision; dosage adjusted due to higher risk of systemic absorption and toxicity

General Guidance:

• Wash and dry the anal area before application

• Apply thinly and only on affected regions to minimize systemic absorption

• Do not use longer than 7 consecutive days unless advised by a physician

• If symptoms persist beyond one week, further evaluation is required

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Pharmacokinetics (Topical/Rectal Use)

• Onset: Rapid, typically within 2–5 minutes

• Duration: 30 minutes to 1 hour (may be extended with occlusion)

• Systemic absorption: Minimal when applied in recommended doses on intact skin/mucosa

• Metabolism: Hepatic (via CYP1A2, CYP3A4)

• Excretion: Renal (as metabolites)

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Contraindications

• Known hypersensitivity to lidocaine or other amide-type local anesthetics

• Severe skin infections or open wounds around the anal area (may increase absorption)

• Severe liver impairment (caution due to metabolism)

• Children under 12 years (except under medical advice)

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Warnings and Precautions

1. Systemic Toxicity Risk:

   • Over-application or use on abraded mucosa can increase systemic absorption, leading to CNS and cardiovascular effects such as dizziness, tremors, seizures, or arrhythmias

2. Methemoglobinemia:

   • Rare but possible; avoid prolonged or excessive use, especially in infants or patients with G6PD deficiency

3. Anal Bleeding or Pain:

   • Persistent bleeding or severe pain may indicate conditions other than hemorrhoids (e.g., fissure, infection, malignancy); medical review required

4. Combination with Corticosteroids:

   • When combined with hydrocortisone, prolonged use can cause local thinning of skin (atrophy)

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Adverse Effects

Local Effects:

• Mild burning or stinging at the site of application

• Temporary redness or irritation

• Allergic contact dermatitis (rare)

Systemic Effects (with overuse):

• CNS symptoms: dizziness, tinnitus, tremors, confusion, seizures (with toxic plasma levels)

• Cardiovascular: hypotension, bradycardia, arrhythmias, cardiac arrest (extremely rare)

• Methemoglobinemia (rare, presents with cyanosis and low oxygen saturation)

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Drug Interactions

• Class I Antiarrhythmics (e.g., mexiletine): Additive cardiac effects

• Beta-blockers (e.g., propranolol): May increase lidocaine plasma levels by reducing hepatic clearance (significant only with high or repeated doses)

• CYP3A4 inhibitors (e.g., erythromycin, cimetidine): May slow lidocaine metabolism

• Other local anesthetics or oxidizing agents: Increased risk of methemoglobinemia

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Use in Pregnancy and Lactation

Pregnancy:

• Category B (US FDA): No known teratogenic effects in humans; considered safe when used topically and in small amounts for short durations.

Lactation:

• Lidocaine is excreted in breast milk in low levels, but the quantities from topical use are too small to affect nursing infants.

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Overdose and Toxicity

Symptoms:

• Early: Metallic taste, numb tongue, tinnitus, dizziness

• Advanced: CNS excitation (tremors, seizures), CNS depression, hypotension, arrhythmias, coma

Management:

• Remove excess drug (wash area)

• Symptomatic treatment (oxygen, seizure control with benzodiazepines)

• Intralipid therapy in severe systemic toxicity

• Emergency cardiac support if required

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Patient Counseling Points

• Clean and dry the anal area before application

• Apply a small, thin layer externally or just inside the anus as instructed

• Avoid using more than 4 times per day unless directed

• Do not use for more than 7 days without medical advice

• Seek medical attention if pain worsens, bleeding increases, or no improvement occurs

• Avoid concurrent use of other rectal products unless prescribed

• Keep away from eyes, mouth, or large areas of broken skin

• Wash hands after application (unless treating fingers)

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Comparison with Other Hemorrhoid Treatments

Treatment	Action	Use
Lidocaine	Local anesthetic	Pain/itch relief
Hydrocortisone	Anti-inflammatory	Reduces swelling and irritation
Zinc oxide	Protectant	Soothes and protects skin
Witch hazel	Astringent	Reduces bleeding and irritation
Phenylephrine	Vasoconstrictor	Shrinks swollen tissue

Lidocaine is often combined with corticosteroids or astringents in multi-ingredient hemorrhoid creams to provide both symptomatic relief and anti-inflammatory benefits.

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Storage

• Store at 15–25°C (59–77°F)

• Protect from light and moisture

• Ensure the cap is tightly closed

• Keep out of reach of children