Usage
This combination medication is primarily prescribed for the treatment of severe diarrhea caused by infections of the digestive tract. It falls under the antidiarrheal and antibacterial pharmacological classifications.
Alternate Names
An alternate name for this combination is Diphenoxylate/Atropine/Furazolidone. A known brand name is Lomofen.
How It Works
Pharmacodynamics:
- Diphenoxylate: A synthetic opioid agonist, acts on the smooth muscle of the intestinal tract, inhibiting excessive gastrointestinal motility and propulsion. This slows down the passage of stool through the intestines, allowing for increased water absorption and firmer stools.
- Atropine: An antimuscarinic agent, is present in a subtherapeutic dose to discourage the misuse of diphenoxylate, as higher doses can lead to dependence. It works by inhibiting the action of acetylcholine, a neurotransmitter that stimulates bowel movements.
- Furazolidone: A nitrofuran antibacterial and antiprotozoal agent that inhibits protein synthesis, thus preventing bacterial and protozoal cell growth in the digestive tract.
Pharmacokinetics:
- Diphenoxylate: Well-absorbed from the GI tract. Metabolized primarily in the liver to diphenoxylic acid (difenoxine), an active metabolite. Excreted mainly in feces and to a lesser extent in urine.
- Atropine: Rapidly and well-absorbed from the GI tract. Distributed widely throughout the body, crossing the placenta and blood-brain barrier. Metabolized incompletely in the liver. Excreted in urine.
- Furazolidone: Well-absorbed after oral administration. Metabolized primarily in the liver. Excreted mainly via renal routes.
Dosage
Standard Dosage
Adults:
Initial dose: 5 mg (two tablets) four times daily.
Maintenance dose: After diarrhea is controlled, the dose can be reduced, sometimes to as low as 5 mg once daily, depending on individual need.
Maximum daily dose: 20 mg diphenoxylate/0.2 mg atropine.
Children:
- Children under 6 years: Use is not recommended.
- Children 6 to under 13 years: Use and dose must be determined by a doctor; liquid formulation only.
- Children 13 years and older: Same as adult dose.
Special Cases:
- Elderly Patients: Start with a lower dose and monitor closely due to potential age-related changes in metabolism and organ function.
- Patients with Renal Impairment: Use with caution. Dose adjustment may be necessary.
- Patients with Hepatic Dysfunction: Use with caution due to the risk of worsening liver function. Dose adjustment may be needed.
- Patients with Comorbid Conditions: Use with caution in patients with ulcerative colitis, glaucoma, prostatic hypertrophy, and other conditions that might be exacerbated by the anticholinergic effects of atropine.
Clinical Use Cases
This medication is typically not used in clinical settings such as intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations.
Dosage Adjustments
Adjustments may be necessary based on individual response, tolerance, and the presence of renal or hepatic impairment.
Side Effects
Common Side Effects:
Abdominal discomfort, nausea, vomiting, constipation, dry mouth, dizziness, drowsiness, headache, loss of appetite.
Rare but Serious Side Effects:
Toxic megacolon (particularly in patients with ulcerative colitis), paralytic ileus, pancreatitis, atropine toxicity (hyperthermia, tachycardia, urinary retention, flushing, dry skin and mucous membranes), severe respiratory depression, coma.
Long-Term Effects:
With prolonged use, especially at higher doses, physical dependence to diphenoxylate can develop.
Adverse Drug Reactions (ADR):
Anaphylaxis, angioneurotic edema, urticaria, severe respiratory depression.
Contraindications
- Hypersensitivity to any component of the medication
- Obstructive jaundice
- Diarrhea associated with pseudomembranous enterocolitis or other enterotoxin-producing bacteria
- Diarrhea associated with inflammatory bowel disease
- Intestinal obstruction
- Children under 6 years of age
Drug Interactions
- CNS depressants (e.g., alcohol, barbiturates, benzodiazepines, opioids): Increased CNS depression.
- Monoamine oxidase inhibitors (MAOIs) (e.g., isocarboxazid, tranylcypromine, furazolidone, selegiline): Risk of hypertensive crisis.
- Anticholinergic drugs: Enhanced anticholinergic effects.
Pregnancy and Breastfeeding
Pregnancy Safety Category: C (consult a doctor before using during pregnancy). This medication may pass into breast milk and is generally not recommended during breastfeeding.
Drug Profile Summary
- Mechanism of Action: Diphenoxylate slows gut motility; atropine reduces secretions and discourages abuse; furazolidone combats infection.
- Side Effects: Common: Dry mouth, constipation, dizziness. Serious: Toxic megacolon, respiratory depression.
- Contraindications: Obstructive jaundice, paralytic ileus, children <6 years.
- Drug Interactions: CNS depressants, MAOIs, anticholinergics.
- Pregnancy & Breastfeeding: Use with caution; potential fetal/neonatal risks.
- Dosage: Adults: Initially 5 mg four times daily, then titrated down. Children: Not recommended under 6 years.
- Monitoring Parameters: Fluid and electrolyte balance, bowel movements, signs of atropine toxicity.
Popular Combinations
This combination itself is commonly used. However, it may be used with oral rehydration solutions to manage fluid and electrolyte loss associated with diarrhea.
Precautions
Use cautiously in patients with liver or kidney disease, glaucoma, prostatic hypertrophy, and ulcerative colitis.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Atropine + Diphenoxylate + Furazolidone?
A: Adults: Initially 5 mg four times daily. This can be reduced to as little as 5 mg once a day after diarrhea is controlled. Not recommended for children under 6 years.
Q2: What are the common side effects?
A: Dry mouth, constipation, dizziness, and drowsiness are common side effects.
Q3: What are the serious side effects?
A: Toxic megacolon, respiratory depression, and atropine toxicity (characterized by fever, tachycardia, flushing, urinary retention) are serious side effects.
Q4: Can this medication be used during pregnancy?
A: It’s a Pregnancy Category C drug. Use only if the benefits outweigh the risks. It’s essential to discuss with a doctor before use.
Q5: Is it safe to breastfeed while taking this medication?
A: This medication can pass into breast milk, and it’s generally not recommended during breastfeeding.
Q6: What are the contraindications for this medication?
A: Contraindications include obstructive jaundice, paralytic ileus, and children under 6 years of age.
Q7: Does this drug interact with alcohol?
A: Yes, avoid alcohol while taking this medication, as it can increase drowsiness and dizziness.
Q8: What should I do if my diarrhea doesn’t improve?
A: Consult your doctor if diarrhea persists beyond 48 hours or if symptoms worsen.
Q9: Are there any specific dietary restrictions while on this medication?
A: Maintain adequate hydration. Initially, a diet of clear liquids and bland foods is recommended.
Q10: Can this combination be used in patients with ulcerative colitis?
A: It should be used cautiously in patients with ulcerative colitis due to the increased risk of toxic megacolon. Close monitoring is necessary.
