Drugs COPY Flashcards
Give examples of proton pump inhibitors
Omeprazole, lansoprazole and pantoprazole
Explain the MoA of PPIs
Irreversibly binding to and inhibition of the ATPase of gastric parietal cells. (Final common pathway)
This reduces acid secretion.
State the major indications for PPIs
Prevention and treatment of peptide ulcer disease
Symptomatic relief of dyspepsia
Treatment of gastro-oesophageal reflux disease
Part of triple therapy for eradication of H.pyolri
What are the adverse effects associated with PPIs
Diarrhoea (Lansoprazole in particular) Headache Abdominal pain Nausea Fatigue Dizziness All relativly uncommon
What are the associated risks of PPIs
Increased risk of C.diff infection
Rebound hypersecretion upon discontinuation
Can mask the sign of gastric cancer
Give examples of histamine type 2 receptor agonists
Ranitidine
Explain the MoA of histamine type 2 receptor agonists
Competitive antagonism of the H2 receptors located on the basolateral membrane of parietal cells. (This is from enterochromaffin-like cells)
This reduces stimulation to the proton pumps, in turn reducing the acid secretion
State the major indications for histamine type 2 receptor agonist
Prophylaxis and treatment of peptic ulcer disease
Symptomatic relief of dyspepsia and GORD (PPIs prefered)
What are the adverse effects associated with histamine type 2 receptor agonist
Less than those of PPIs Diarrhoea and less commonly constipation Headache Abdominal pain Dizziness All uncommon
What risks are associated with histamine type 2 receptor agonist
Can mask signs of gastric cancer
Give examples of Alginates & Antacids
Gaviscon, Peptac, Mucogel
Prescribed as brand names
Explain the MoA of Alginates & Antacids
Act as a buffer to the gastric contents
State the major indications for Alginates & Antacids
Gastro-oesophageal reflux disease for symptomatic relief
Dyspepsia for a short term relief
What are the adverse effects associated with Alginates and Antacids
Non recorded
What are the risks associated with Alginates and Antacids
High sodium and potassium so should be avoided in the salt restricted diet
Give examples of antimuscarinic drugs
Hyoscine butyl-bromide
Explain the MoA of antimuscarinic drugs
A competitive antagonist of muscarinic ACh receptors (M3) and thus oppose the action of the parasympathetic innervation to the gut.
This reduces spasm of the smooth muscle peristalsis.
State the major indication for antimuscarinic drugs
To relieve smooth muscle spasm in IBS. (symptomatic relief)
What are the adverse effects associated with antimuscarinic drugs
Suppression of the parasympathetic division of the ANS. Tachycardia Dry mouth Constipation Urinary retention Blurred vision
What are the risks associated with antimuscarinic drugs
Used in caution with cardiac arrhythmias
Give examples of antimotility drugs
Loperamide (prefered due to not crossing the BBB, no narcotic effect) Codeine phosphate (prefered if analgesia is also needed, mostly in palliation)
Explain the MoA of antimotility drugs
Action to reduce the peristaltic action whilst increasing the tone and rhythmic contractions of the intestine.
State the major indications for antimotility drugs
Treatment of acute diarrhoea for symptomatic relief (infective gastroenteritis normally)
Symptomatic relief of diarrhoea associated with IBS
What are the adverse effects associated with antimotility drugs
Constipation
Abdominal cramping
Flatulence
What are the contradictions to the use of antimotility drugs
Acute ulcerative colitis
Acute bloody diarrhoea
C.diff colitis
Hospital setting with an unknown aetiology
Give examples of aminosalicylates
Mesalazine
Balsalazide
Explain the MoA of aminosalicylates
These drugs break down to form 5-ASA
5-ASA acts locally as an anti-inflammatory and immunosuppressant.
State the major indications for aminosalicylates
First line treatment of mild to moderate ulcerative colitis
What are the adverse effects associated with aminosalicylates
Commonly causes GI upset and headaches
Possible blood abnormalities, leading to renal complications
What are the contraindications for aminosalicylates
Avoid in use for those with aspirin hypersensitivity
Give examples of bulk-forming laxatives
Ispagula husk
Explain the MoA of bulk-forming laxatives
Hydrophilic agents so osmotically draw water to the stool increasing its bulk which in turn stimulates peristalsis
Faecal consistency is improved
(Note that an important fluid ingestion is important for this group as they take 2-3 days to impose action)
State the major indications for bulk-forming laxatives
Constipation adn faecal impaction
Mild chronic diarrhoea assocaites with diverticular disease or IBS
What are the adverse effects of bulk-forming laxatives
Abdominal distention
Flatulence
Rarely cause faecal impaction and GI obstruction
What are the contraindications of bulk-forming laxatives
Intestinal obsution
Avoid in ileus