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GIT - Proton pum inhibitors (PUD) - Histamine Receptor Antagonists

Q: What is the oral dosage for Ranitidine?

Ranitidine 150mg is administered in the morning and at bed time. The total dose may be given at bed time, but efficacy is reduced.

Q: How is Famotidine administered according to the dosage instructions?

Famotidine 20mg is taken in the morning and at bed time. The total dose may be given at bed time, but efficacy is reduced.

Q: When are H2 blockers given by I.V. injection or infusion?

H2 – blockers are given by slow I.V injection or infusion in acute and severe cases only.

26 important questions on GIT - Proton pum inhibitors (PUD) - Histamine Receptor Antagonists

What are some cardiovascular adverse effects of rapid I.V infusion of H2-blockers?

Rapid I.V infusion may decrease cardiac output, induce arrhythmias or heart block. These are some cardiovascular adverse effects associated with the use of H2-blockers.

What are some adverse effects of H2-blockers?

Adverse effects of H2-blockers include:

Tolerance and rebound hyper-acidity (due to up regulation of H2 receptors)
Recurrence on withdrawal
Hypochlorhydria
Gastric colonization by bacteria with formation of carcinogenic nitroso-compounds from salivary and dietary nitrate

What psychological effects can H2-blockers cause?

Confusion, hallucinations, insomnia, and depression are psychological effects that may occur with the use of H2-blockers. These effects can impact mental health significantly.

What is the oral dosage for Ranitidine?

Ranitidine 150mg is administered in the morning and at bed time. The total dose may be given at bed time, but efficacy is reduced.

What are some sexual side effects of H2-blockers?

Impotence and loss of libido are sexual side effects associated with the use of H2-blockers. These effects can affect sexual health and function.

What is noted about GERD in therapeutic uses?

GERD has lower healing and higher recurrent rates than peptic ulcer. It is listed as a therapeutic use under point 4.

How is Famotidine administered according to the dosage instructions?

Famotidine 20mg is taken in the morning and at bed time. The total dose may be given at bed time, but efficacy is reduced.

What dermatological adverse effects can H2-blockers cause?

Skin rash and alopecia are dermatological adverse effects that may occur with the use of H2-blockers. These effects can affect the skin and hair.

What is the short-term therapy duration and healing rate for a duodenal ulcer?

Short-term therapy for a duodenal ulcer is 4 weeks with a healing rate of 70%, and 8 weeks with a healing rate of 90%.

When are H2 blockers given by I.V. injection or infusion?

H2 – blockers are given by slow I.V injection or infusion in acute and severe cases only.

What type of antagonists are H2 receptor blockers?

H2 receptor blockers are reversible competitive antagonists. They decrease intracellular cAMP particularly in parietal cells. They are potent inhibitors of all phases of HCl secretion.

How long is maintenance therapy for a duodenal ulcer?

Maintenance therapy for a duodenal ulcer involves one dose at bedtime for 1 to 5 years.

What is the preferred method for treating stress ulcers?

For stress ulcers, I.V injection or infusion is preferred. This is mentioned under therapeutic use number 7.

What are the histamine H2 receptor antagonists listed?

The histamine H2 receptor antagonists listed include:

Ranitidine
Famotidine
Nizatidine
Cimetidine

How do H2 receptor antagonists affect acid secretion?

They induce reduction in fasting and nocturnal acid secretion (main effect) but less reduction in meal stimulated and daytime acid secretion.

How effective are H2 blockers for gastric ulcers compared to duodenal ulcers?

H2 blockers are less effective for gastric ulcers than in duodenal ulcers due to normal or low HCl, delaying healing by 2 to 4 weeks.

What is the therapeutic use related to emergency surgery?

Adjuvant to anesthesia in emergency surgery to avoid aspiration pneumonia is listed as therapeutic use number 8.

What is significant about Cimetidine among H2 blockers?

Cimetidine is the 1st H2 blocker in this class. It has limited use due to non-specificity, hence the widespread adverse effects.

What conditions are mentioned alongside gastric ulcers in the therapeutic uses?

Acute gastritis and gastric erosions are mentioned alongside gastric ulcers in the therapeutic uses.

What is the preferred medication for combination therapy in H. pylori?

Ranitidine is preferred for combination therapy in H. pylori, as mentioned in therapeutic use number 9.

What is a limitation of H2-receptor antagonists in PUD related to HCL secretion?

There is a lack of day time and meal stimulated reduction of HCL secretion. This is a limitation of H2-receptor antagonists in PUD.

What are the specific adverse effects caused by Ranitidine?

Gynaecomastia and Galactorrhoea (weak anti-androgen effect)
Bone marrow depression
Hepatic Enzyme inhibition

What issue related to acidity is a limitation of H2-receptor antagonists in PUD?

Tolerance and rebound hyper-acidity are limitations of H2-receptor antagonists in PUD.

How do H2-receptor antagonists affect healing rates in GERD?

Lower healing rates in Gastro-Esophageal Reflux Disease (GERD) are a limitation of H2-receptor antagonists.

What is the effectiveness of Famotidine in anti-H. pylori regimens?

Famotidine is not effective in anti-H. pylori regimens. This is a limitation of H2-receptor antagonists in PUD.

How does Ranitidine compare to PPIs in anti-H. pylori regimens?

Ranitidine is less effective than Proton Pump Inhibitors (PPI’s) in anti-H. pylori regimens. This is a limitation of H2-receptor antagonists.

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Phamarcology

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