charcoal

Usage

• Activated charcoal is used to treat poisonings. It works by binding to the poison in the stomach and intestines, preventing its absorption into the bloodstream. Activated charcoal is also used to reduce intestinal gas (flatulence) and lower cholesterol levels. More research is needed to confirm the effectiveness for these uses.
• Pharmacological Classification: Adsorbent, antidote.

Alternate Names

• Activated charcoal
• Activated carbon
• Active Carbon
• Carbomix
• Medicoal
• Norit

How It Works

• Pharmacodynamics: Activated charcoal acts by adsorbing toxins and drugs in the gastrointestinal tract, thus preventing their systemic absorption. It has a broad spectrum of adsorptive activity and can bind to a wide range of substances, but it’s not effective against all toxins (e.g., alcohols, corrosives, iron, lithium, heavy metals, mineral acids).
• Pharmacokinetics: Activated charcoal is not absorbed systemically. It passes through the GI tract and is eliminated in the feces, giving stools a black color.
• Mode of Action: Adsorption to the surface of the charcoal particles. Activated charcoal does not bind chemically to toxins or drugs. The porous structure of activated charcoal provides a large surface area for binding, enhancing its capacity to adsorb various molecules. This is a purely physical process, not involving receptor binding, enzyme inhibition, or neurotransmitter modulation.
• Elimination Pathways: Primarily fecal excretion.

Dosage

Standard Dosage

Adults:

• Poisoning: Initial dose: 50-100g orally. Multiple doses: 25-50g every 2-4 hours, or 50-100g every 4-6 hours as needed.
• Flatulence: 200-400mg orally daily, divided into two doses taken before or after meals (maximum 1.5g/day).

Children:

• Poisoning:
  • Under 1 year: 1g/kg orally, may repeat every 4-6 hours.
  • 1-12 years: 25-50g orally, may repeat every 4-6 hours.
  • Over 12 years: 50-100g orally, may repeat every 4-6 hours.
• Pediatric safety considerations: Avoid in children with unprotected airways or impaired consciousness unless intubated. Caution should be exercised due to risk of aspiration and vomiting. Charcoal/sorbitol combinations are generally not recommended for young children due to the risk of diarrhea.

Special Cases:

• Elderly Patients: Similar to adult dosing, monitor for constipation, especially with multiple doses.
• Patients with Renal Impairment: No specific dose adjustment is typically required.
• Patients with Hepatic Dysfunction: No specific dose adjustment is typically required.
• Patients with Comorbid Conditions: Use with caution in patients with gastrointestinal conditions such as bowel obstruction or reduced peristalsis.

Clinical Use Cases

Activated charcoal’s clinical use is primarily focused on the management of acute poisonings. While some other uses are being explored, they lack substantial clinical evidence to support widespread application in these settings.

• Intubation, Surgical Procedures, Mechanical Ventilation, Intensive Care Unit (ICU) Use, and Emergency Situations: Activated charcoal is not typically indicated in these situations unless directly related to a poisoning.

Dosage Adjustments

• Dose adjustments may be needed for multiple-dose activated charcoal (MDAC) depending on the specific poison, its pharmacokinetics, and the patient’s clinical response. Consult a poison control center or toxicology expert for guidance.

Side Effects

Common Side Effects

• Black stools
• Constipation
• Vomiting (especially when co-administered with sorbitol)

Rare but Serious Side Effects

• Bowel obstruction (especially with multiple doses or in patients with pre-existing motility disorders)
• Pulmonary aspiration

Long-Term Effects

No significant long-term adverse effects have been reported with appropriate use for acute poisoning. Chronic use is not typically recommended and lacks long-term safety data.

Adverse Drug Reactions (ADR)

• Anaphylaxis (rare)

Contraindications

• Unprotected airway
• Ingestion of corrosive substances (acids, alkalis)
• Known or suspected bowel obstruction
• Decreased level of consciousness with risk of aspiration

Drug Interactions

Activated charcoal can adsorb numerous medications, reducing their absorption and effectiveness. Administer other oral medications at least 2 hours before or 1 hour after activated charcoal. Significant interactions can occur with:

• Acetylcysteine
• Citalopram
• Digoxin
• Methotrexate
• Theophylline
• Oral contraceptives
• Many other drugs (consult a drug interaction database for a comprehensive list)

Pregnancy and Breastfeeding

• Pregnancy Safety Category: Australian TGA category B2. US FDA category: Not assigned. Considered generally safe for short-term use in pregnancy.
• Breastfeeding: Generally considered safe for short-term use during breastfeeding. Activated charcoal is not systemically absorbed and is not expected to pass into breast milk in significant amounts. However, caution is advised, especially regarding dosage and frequency.

Drug Profile Summary

• Mechanism of Action: Adsorption of toxins and drugs in the GI tract.
• Side Effects: Black stools, constipation, vomiting.
• Contraindications: Unprotected airway, corrosive ingestion, bowel obstruction, decreased level of consciousness.
• Drug Interactions: Reduces absorption of many medications.
• Pregnancy & Breastfeeding: Generally considered safe for short-term use.
• Dosage: Varies depending on indication and age. See detailed dosage section above.
• Monitoring Parameters: Monitor vital signs, level of consciousness, and bowel sounds. For multiple doses, monitor electrolyte levels.

Popular Combinations

Activated charcoal is sometimes given with sorbitol (a cathartic) to promote bowel elimination of the toxin. However, this combination can cause significant diarrhea, especially in children, and its use is generally limited to the initial dose. Multiple-dose activated charcoal (MDAC) is sometimes used without sorbitol for certain poisonings.

Precautions

• General Precautions: Assess airway patency, level of consciousness, and risk of aspiration before administering.
• Specific Populations: See dosage adjustments and pregnancy/breastfeeding information.
• Lifestyle Considerations: None specific to activated charcoal.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for charcoal in adults with poisoning?

A: Initial dose is 50-100g, followed by 25-50g every 2-4 hours or 50-100g every 4-6 hours as needed.

Q2: Can activated charcoal be used for all types of poisoning?

A: No, it is not effective for all toxins, such as alcohols, corrosives, iron, lithium, heavy metals, and mineral acids.

Q3: What are the common side effects of activated charcoal?

A: Common side effects are black stools, constipation, and vomiting (especially when given with sorbitol).

Q4: Is activated charcoal safe to use in pregnant or breastfeeding women?

A: It’s generally considered safe for short-term use during pregnancy and breastfeeding. Consult a healthcare professional before use.

Q5: Can activated charcoal interact with other medications?

A: Yes, it can reduce the absorption of many oral medications. Administer other medications at least 2 hours before or 1 hour after activated charcoal.

Q6: When should activated charcoal be avoided?

A: Avoid in cases of unprotected airway, ingestion of corrosive substances, bowel obstruction, or decreased level of consciousness with risk of aspiration.

Q7: How does activated charcoal work?

A: It works by adsorbing (binding to) the poison in the GI tract, preventing its absorption into the bloodstream.

Q8: Are there any long-term effects of using activated charcoal?

A: No significant long-term adverse effects have been reported with appropriate use for acute poisoning. Chronic use is not typically recommended.

Q9: What is multiple-dose activated charcoal (MDAC)?

A: MDAC involves administering repeated doses of activated charcoal over a period, usually for toxins with prolonged absorption or enterohepatic recirculation.

Q10: What should I do if a patient develops vomiting after receiving activated charcoal?

A: Monitor for aspiration risk. If vomiting is severe, consider alternative routes of detoxification if appropriate for the ingested substance. Anti-emetics may be necessary in some cases. Consult with a poison control center or toxicologist.