Chlorocresol

Usage

• Medical Conditions: Chlorocresol is primarily used as an antiseptic and preservative in a variety of pharmaceutical and personal care products. It can be found in topical creams, ointments, lotions, gels, and solutions for skin disinfection and wound care. It is also employed as a preservative in injectable medications and other preparations containing water. Furthermore, chlorocresol is present in some over-the-counter products for the relief of mouth ulcer pain and denture irritation, often combined with local anesthetics like lidocaine. In certain combination products, it is used to manage inflammatory skin conditions complicated by fungal and bacterial infections.
• Pharmacological Classification: Antiseptic, preservative, disinfectant.
• Mechanism of Action: Chlorocresol acts by disrupting the cell membranes of microorganisms, leading to their inactivation or death. It exhibits broad-spectrum activity against bacteria and fungi.

Alternate Names

• Other Names: p-chloro-m-cresol (PCMC), 4-chloro-3-methylphenol, parachlorometacresol.
• Brand Names: Preventol CMK, Anbesol (in combination with other active ingredients), and it can be found as a preservative in various other branded products.

How It Works

• Pharmacodynamics: Chlorocresol’s primary effect is to kill or prevent the growth of bacteria and fungi on the skin or other application sites. It works by disrupting the cell membranes of these microorganisms, which leads to leakage of cellular contents and ultimately their death. It does not typically have significant systemic effects when used topically in the recommended concentrations.

• Pharmacokinetics: When applied topically, chlorocresol absorption through intact skin is minimal. However, absorption can increase if the skin is damaged or if large surface areas are treated, especially for prolonged periods. If absorbed systemically, it is metabolized primarily in the liver, predominantly by glucuronidation and sulfation. Elimination is primarily through renal excretion. When used in oral formulations like Anbesol, small quantities of Chlorocresol can be absorbed through the mucous membranes.

• Mode of Action/Receptor Binding/Enzyme Inhibition: The primary mode of action is through disrupting microbial cell membranes. There is no known specific receptor binding or enzyme inhibition involved in its antiseptic action.

• Elimination Pathways: Primarily renal excretion of metabolites after hepatic metabolism (glucuronidation and sulfation).

Dosage

Chlorocresol is not typically prescribed as a standalone medication, and its dosage varies widely depending on the formulation and its intended use.

Standard Dosage

The dosage recommendations below apply to Anbesol products containing chlorocresol for oromucosal use:

Adults: Apply a small amount to the affected area with a clean fingertip every 3 hours as needed. Do not exceed six applications within a 24-hour period.

Children (5 months and older): Apply a pea-sized amount to the affected area with a clean fingertip every 3 hours as needed. Do not exceed six applications within a 24-hour period. Do not use in children under 5 months old.

Special Cases: Due to the limited systemic absorption of chlorocresol when applied topically as directed, dosage adjustments in special populations (elderly, renally impaired, hepatically impaired, or those with comorbid conditions) are generally not necessary. However, caution should be exercised if applying to large areas of broken skin.

Clinical Use Cases (As a Preservative): As a preservative in pharmaceutical preparations, the concentration of chlorocresol usually ranges from 0.1% to 0.2%. In some cases, such as in multi-dose vials, the concentration might be higher to maintain sterility over extended periods and repeated uses.

Dosage Adjustments (As a Preservative): No specific dosage adjustments are made for chlorocresol as a preservative. The formulation determines the concentration, and adjustments would apply to the primary drug in the preparation, not the preservative.

Side Effects

Common Side Effects:

• Skin irritation (e.g., redness, itching, burning sensation).
• Allergic contact dermatitis (in individuals sensitive to chlorocresol).

Rare but Serious Side Effects:

• Severe skin reactions, although rare, can occur.

Long-Term Effects: No specific long-term effects are associated with the topical use of chlorocresol when used as directed.

Adverse Drug Reactions (ADR): Hypersensitivity reactions are the most significant ADRs, although uncommon.

Contraindications

• Known hypersensitivity to chlorocresol.

Drug Interactions

• Chlorocresol can be incompatible with some other compounds, such as non-ionic surfactants, which may reduce its antiseptic activity.

Pregnancy and Breastfeeding

• Pregnancy: Limited information is available regarding the safety of chlorocresol use during pregnancy. Use only if the potential benefit outweighs the potential risk to the fetus.
• Breastfeeding: It is unknown whether chlorocresol is excreted in human breast milk. Caution is advised during breastfeeding.

Drug Profile Summary

• Mechanism of Action: Disrupts microbial cell membranes, causing leakage and death.
• Side Effects: Skin irritation, allergic contact dermatitis (rare).
• Contraindications: Hypersensitivity to chlorocresol.
• Drug Interactions: Incompatible with certain excipients.
• Pregnancy & Breastfeeding: Use with caution; safety not fully established.
• Dosage: Varies depending on the product. For Anbesol, apply sparingly every 3 hours as needed. Maximum of 6 applications in 24 hours. Not to be used in children under 5 months old.
• Monitoring Parameters: Not routinely monitored.

Popular Combinations

• Chlorocresol is often combined with lidocaine hydrochloride and cetylpyridinium chloride in oral gels and solutions to provide both anesthetic and antiseptic effects (e.g. Anbesol). It is also often used in combination with corticosteroids, antifungals, and antibiotics for topical skin formulations to treat inflamed skin conditions susceptible to infection.

Precautions

• General Precautions: Avoid contact with eyes. In case of accidental contact, rinse thoroughly with water.
• Specific Populations: As noted above for Pregnancy and Breastfeeding.
• Lifestyle Considerations: No specific lifestyle considerations are associated with the topical use of chlorocresol.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Chlorocresol?

A: The dosage depends on the formulation and intended use. For oromucosal gels like Anbesol containing chlorocresol, adults and children 5 months and older can apply a small amount to the affected area every 3 hours as needed, not exceeding six applications in 24 hours. Do not use in children under 5 months old. As a preservative, its concentration typically ranges from 0.1% to 0.2%.

Q2: Can Chlorocresol be used during pregnancy or breastfeeding?

A: Limited data are available on the safety of chlorocresol use during pregnancy and breastfeeding. Use with caution and only if the potential benefit outweighs the potential risk.

Q3: What are the most common side effects of Chlorocresol?

A: The most common side effects are mild and include skin irritation, such as redness, itching, and a burning sensation. Allergic contact dermatitis can occur in individuals sensitive to chlorocresol.

Q4: What is the mechanism of action of Chlorocresol?

A: Chlorocresol exerts its antiseptic effects primarily through disrupting the cell membranes of microorganisms, causing their inactivation or death.

Q5: Is Chlorocresol effective against all types of bacteria and fungi?

A: Chlorocresol has a broad spectrum of activity but is not effective against all microorganisms. Its efficacy varies depending on the specific strain and concentration.

Q6: Can Chlorocresol be used on open wounds?

A: Yes, chlorocresol can be used on open wounds due to its antiseptic properties. However, caution should be exercised, and it should not be applied to large areas of broken skin due to the potential increased risk of systemic absorption.

Q7: How is Chlorocresol metabolized and eliminated from the body?

A: Chlorocresol is primarily metabolized in the liver via conjugation reactions, mainly glucuronidation and sulfation, and the metabolites are subsequently excreted in the urine.

Q8: Are there any drug interactions with Chlorocresol?

A: Chlorocresol can be incompatible with some other ingredients in topical and pharmaceutical formulations, especially some non-ionic surfactants, which may reduce its efficacy.

Q9: What should be done in case of accidental ingestion of Chlorocresol?

A: If a significant quantity of a product containing chlorocresol is ingested, seek immediate medical attention.

Q10: How should Chlorocresol be stored?

A: Pharmaceutical products containing chlorocresol should be stored as directed on the product labeling. Generally, they should be kept in a cool, dry place away from direct sunlight and out of reach of children.