GIT Lec 3 Pt 2 - Anti-motility (opioids) Medications

Question 1

What are the drugs that are found in this class?

Answer 1

Loperamide, Diphenoxylate with atropine and Codeine

Question 2

What are the pharmacokinetics of Diphenoxylate?

Answer 2

1. Diphenoxylate is given as 2.5mg Diphenoxylate with 0.025mg atropine.
2. It resembles pethidine in structure and affects the bowels like codeine.
3. It is absorbed in the intestines and it can pass the blood-brain-barrier causing CNS disturbances and without atropine; it can lead to addiction.
4. Diphenoxylate acts both locally and centrally to reduce intestinal motility; atropine has anti-Cholinergic effects which makes it synergistic with Diphenoxylate; however atropine is given at doses that are below therapeutic doses to prevent abuse due to overdose
5. It begins its action within 45-60 minutes and lasts for 3-4 hours. In adults, it is usually given twice a day to a maximum of 4 times daily.
6. It has a half life of 3 hours.

Question 3

What are the adverse effects of Diphenoxylate?

Answer 3

1. GIT effects: abdominal discomfort, nausea and vomiting
2. CNS effects: drowsiness and dizziness
3. Psychogenic effects: anorexia nervosa, lethargy and euphoria

Question 4

What are the contraindications of Diphenoxylate?

Answer 4

1. Jaundice, atropine intolerance and Diphenoxylate allergy.
2. Children under 6.
3. Patients with acute colitis

Question 5

What are the pharmacokinetics of Loperamide?

Answer 5

1. It resembles morphine.
2. It has weak anti-Cholinergic effects. It also doesn’t penetrate the brain wall which makes it relatively free of central opiate effect.
3. It is indicated in adult patients for control and symptomatic relief of acute, nonspecific diarrhea, and for chronic diarrhea associated with inflammatory bowel diseases. It is also considered the first-line medication for traveler’s diarrhea that is parasitic, bacterial or viral in origin.
4. It has a half life of 10 hours.
5. In adults, the dose is 4 mg followed by 2 mg after each bowel motion with a maximum of 16 mg daily.

Question 6

What are the adverse effects of loperamide?

Answer 6

1. Skin rashes
2. GIT disturbances
3. Intestinal stasis

Question 7

What are the contraindications of loperamide?

Answer 7

1. Children under 6.
2. Patients with constipation.
3. Patients with pseudomembranous colitis; induced by broad-range antibiotics; it can lead to abdominal distention and peralytic ileum.