Pharmacology

Question 1

Aailable treatments for gastric ulcers?

Answer 1

Anti-acids

1. Systemic (acts on blood pH, not good)
2. Non-systemic

Cimetidine

• Zantac (less effects)

Propantheline

Omeprazole

Sucralfate

Question 2

Antiacid actions?

Answer 2

Neutralizing acids. Types:

• Sodium and potassium
  
  • Rapid onset short duration of action
• Calcium
  
  • Rapid onset
  • Long duration of action
  • But limited effect on pH
• Magnesium
  
  • Rapid onset, large effect on pH
  • But acts as a laxative
• Aluminum

Slow onset and is constipative

Question 3

Cimetidine action?

Answer 3

Zantac has less side effects

• Histamine (H2) receptor blocker
• Short duration of action
• Interaction with p450 enzymes
• Anti-androgenic effects

Question 4

Propantheline action?

Answer 4

• M1 M3 blockers
• Anti-androgenic effects

Question 5

Omeprazole action?

Answer 5

• H+K+ ATPase pump blockers
• Side effect: Gastric mucosal hyperplasia

Question 6

Sucralfate action?

Answer 6

Mucosa protecting drug

Question 7

Treatment of gastroparesis?

Answer 7

Bethanecol

Metoclopromide and Domperidone

Metoclopromide

Cisapride

Neostigmine

Erythromycin

Question 8

Bethanecol action?

Answer 8

Cholinergic derivative

• Activated muscarinic receptors which stimulates muscle cells of GI tract
• Can lead to systemic side effects

Question 9

Metoclopromide and Domperidone action?

Answer 9

Prokinetic D2 antagonist

• Blocs dopamine (Parkinson like symptoms)
• Increase gastric contraction, coordination of gastroduodenal, lower sphincter tone and gastric emptying
• Decreases emesis and inhibitory presynaptic D2 receptor
• BUT Increase in prolactin and breast tenderness

Question 10

Metoclopromide and Cisapride action?

Answer 10

5HT4 agonists

• Stimulate 5HT4r at smooth muscle of GI, Urinary bladder, adrenal gland by calcium increase
• Activate Adenylate cyclase cAMP
• Controls nausea and vomiting (emesis)
• Increase gastroduodenal coordination, gastric and lower sphincter contraction
• BUT extrapyramidal effects caused by dopamine blockade, galactorrhea and cardiac arrhythmias

Question 11

Neostigmine action?

Answer 11

ACE inhibitor

• Inhibit acetylcholine esterase and stimulate smooth muscle cells of GI tract like bethanecol

Question 12

Erythromycin action?

Answer 12

Motilin agonist

• Increase lower LES and GI contractility

Question 13

Types of laxatives?

Answer 13

• Lubiprostone: Secretory or stimulant: castor oil: prostaglandin analog
• Magnesium hydroxide, sodium phosphate, sodium sulfate: Saline laxative
• Docusate and Anionic surfactant: Emolient laxative
• Mineral oil: Lubricant laxative
• Bran, psyllium husk: Hydrophilic bulk

Question 15

Antidiarrheal agents?

Answer 15

1. Opioids, morphine codeine
2. Loperamide, diphenoxylate (no effect of CNS)