Opioid antidiarrheal medications: Loperamide and diphenoxylate

Summary

Loperamide and diphenoxylate are opioid receptor agonists used to treat diarrhea by reducing intestinal motility, allowing more water to be absorbed from feces. Loperamide is preferred due to its lower risk of addiction, fewer side effects, and minimal central nervous system effects. Diphenoxylate, although effective, can cause CNS depression and is combined with atropine to reduce addiction risk. Loperamide should be avoided in cases of bloody diarrhea, bacterial enterocolitis, or in children under three. Proper assessment of hydration and electrolyte balance is recommended before treatment.

Takeaways

• 😀 Loperamide and diphenoxylate are opioid receptor agonists used to treat diarrhea.
• 😀 Loperamide is preferred over diphenoxylate due to its lower risk of addiction and fewer side effects.
• 😀 Diphenoxylate is often sold in combination with atropine to reduce its addictive properties.
• 😀 Both drugs work on opioid receptors in the gut to reduce intestinal movement and allow more water absorption from fecal matter.
• 😀 Loperamide is poorly absorbed in the gastrointestinal tract, meaning it mainly acts locally and has little effect on the brain.
• 😀 Diphenoxylate is well absorbed and crosses the blood-brain barrier, making it a central nervous system depressant.
• 😀 Loperamide is considered safer and more effective than diphenoxylate for treating diarrhea.
• 😀 Overuse of diphenoxylate can lead to respiratory depression, which can be reversed with naloxone.
• 😀 Loperamide should not be used in children under three years old or in cases of bloody diarrhea or bacterial enterocolitis.
• 😀 Before administering loperamide, it's important to assess the patient's hydration status and look for any electrolyte imbalances.
• 😀 The typical dosage for loperamide starts with a loading dose, followed by a standard dose for up to 48 hours before discontinuation.

Q & A

What are loperamide and diphenoxalate used for?

Loperamide and diphenoxalate are opioid-containing anti-diarrheal agents used to decrease diarrhea by reducing the motility of the intestines.

How do loperamide and diphenoxalate work to reduce diarrhea?

Both drugs act on opioid receptors in the myenteric plexus of the intestines, decreasing muscle activity, slowing down intestinal movement, and allowing more water to be absorbed from fecal matter.

Why is loperamide preferred over diphenoxalate?

Loperamide is preferred because it has fewer side effects, is less likely to cause addiction, and is generally safer compared to diphenoxalate.

What is the main difference between the absorption of loperamide and diphenoxalate?

Loperamide is poorly absorbed in the gastrointestinal tract and has minimal effects on the central nervous system, while diphenoxalate is well absorbed and can cross the blood-brain barrier, affecting the CNS.

What are the safety concerns with diphenoxalate?

Diphenoxalate poses a risk of addiction and central nervous system depression, and if overused, it can lead to respiratory depression, which requires naloxone to reverse.

What are the main safety precautions for using loperamide?

Loperamide should not be used in children under three years old, in cases of bloody diarrhea, or in bacterial enterocolitis. An assessment of hydration and electrolyte balance is necessary before use, especially in vulnerable populations.

How is loperamide typically administered?

Loperamide is typically given with a loading dose (double the normal dose) initially, followed by normal doses for up to 48 hours, after which the medication should be discontinued.

Why is it important to assess hydration and electrolytes before giving loperamide?

Because diarrhea can lead to dehydration and electrolyte imbalances, it is important to assess these factors to avoid worsening the patient’s condition, especially in young or elderly individuals.

What is the role of atropine in combination with diphenoxalate?

Atropine is added to diphenoxalate to decrease its addictive properties and reduce the likelihood of misuse.

What should be done if a person experiences respiratory depression due to diphenoxalate overdose?

If respiratory depression occurs from a diphenoxalate overdose, naloxone should be administered to reverse the effects.