Gastroenterology Flashcards
Magnesium Trisilicate
Indications: Dyspepsia
MOA: Antacid –> Increases pH, neutralises gastric acid
S/E’s: Diarrhoea, belching due to liberated CO2
CI’s: - Hypophosphataemia
Interactions: Can affect absorption of other drugs therefore take it separately
**Other info: **Take when sypmtomatic or when expect symptoms
Aluminium Hydroxide
**Indications: **Dyspepsia, Hyperphosphataemia
**MOA: **Antacid –> Increases pH, neutralises gastric acid
S/E’s: Constipation
**CI’s: **Hypophosphataemia (PO4), Neonates and Infants
Interactions: Can affect absorption of other drugs therefore take separately
Other info: Take when symptomatic or when symptoms expected
Gaviscon
10-20mL after meals and bedtime
Oral solution
- *Indications**: Dyspepsia, GORD
- *MOA:** Na Alginate –> decreases reflux (increases viscosity of stomach contents and forms a raft on top of the stomach contents)
- *S/E’s:** -
- *CI’s:** -
- *Interactions:** -
- *Other info:** - Multiple flavours e.g. Aniseed, peppermint, sugar-free
**Omeprazole **
**Lansoprazole **
**Pantoprazole **
**Esomeprazole **
20 - 40mg OD Oral
- *Indications:** GORD, Dyspepsia, PUD, Helicobacter pylori, Prevention and treatment of NSAID associated ulcers, Zollinger Ellison disease
- *MOA: **Proton pump inhibitors –> Activated in acidic pH, irreversibly inhibit H/K/ATPase pump in parietal cells
- *S/E’s:** GI disturbance - N,V+D, headache
- *CI’s:** Lower dose in hepatic impairment
- *Interactions:** P450 inhibitor (Omeprazole)
- *Other info:** More effective than H2R antagonists. CAUTION - can mask symptoms of gastric ca. Increases likelihood of aspiration pneumonia. Can give by IV injection or infusion if need to.
Helicobacter Pylori Eradication Regime
_PAC-500 _= PPI: Lansoprazole 30mg BD, Amoxicillin 1g BD, Clarithromycin 500mg BD
PMC-250** = PPI: **Lansoprazole 30mg BD, Metronidazole 400mg BD, Clarithromycin 250mg BD
7 days of Rx
Rem: PPI’s/H2RA’s = false negative C13 breath tests/antigen tests therefore stop 2 weeks before test
**Cimetidine **
Ranitidine
C - 400mg BD/800mg nocte
R - 150mg BD/300mg nocte
- *Indications:** GORD, PUD, functional dyspepsia
- *MOA:** H2R antagonist therefore descreases gastric parietal cell H+ secretion
- *S/E’s: **Mainly cimetedine –> GI disturbance, headache, dizziness
- *CI’s:** Decrease dose in hepatic and renal impairment
- *Interactions: **Cimetidine is a P450 inhibitor therefore avoid in pts on warfarin, phenytoin and theophylline
- *Other info:** Can mask symptoms of gastric ca. Take at night time.
Misoprostol
200 micrograms QDS with meals and nocte
- *Indications:** NSAID associated PUD, abortion, delayed miscarriage and to induce labour (uterine stimulant)
- *MOA:** Prostaglandin analogue –> acts on parietal cells to decrease H+ secretion, also has protective properties and promotes ulcer healing
- *S/E’s:** Diarrhea = very common, abdo pain, flatulence, N+V, abnormal PV bleeding
- *CI’s:** PREGNANCY/ Women of child bearing age (teratogenic in 1st trimester), caution in IBD/CVD/IHD
- *Interactions:** -
- *Other info:** Often given in combination with NSAID (Diclofenac + Misoprostol = Arthrotec)
Ispaghula husk (Fybogel)
Bran
Methylcellulose
Sterculia
- *Indications:** CONSTIPATION - can be used in those with stomas, haemorrhoids, anal fissures, IBS, IBD and diverticular disease.
- *MOA:** Bulk forming laxatives –> increase faecal mass which stimulates peristalsis. Can take several days to work.
- *S/E’s:** Flatulence, abdo distension/ bloating
- *CI’s:** Bowel obstruction, faecal impaction, difficulty swallowing
- *Interactions: -**
- *Other info: **Very useful in those with small hard stools.Counsel pt re adequate fluid and fibre intake to avoid constipation. Try bran first, then ispaghula.
Sodium Docusate
Sodium Picosulfate
**Senna (an anthraquinone) **Tablets 7.5mg 2-4 tablets nocte
Glycerol PR suppositories x 1 PRN
Stimulant laxatives
Indications: CONSTIPATION
MOA: Stimulant laxatives –> increase intestinal motility
S/E’s: Abdo cramp/colic, excess use causes diarrhoea and hypokalaemia
CI’s: -
Interactions: -
Other info: Senna acts in 8-12 hours
**Lactulose **solution 15mL BD
**Macrogol - Movicol **oral powder
**Phosphate enemas **bowel clearance prep pre op/radiology etc
**Mg Salts **used in rapid bowel evactuation
Osmotic laxatives
- *Indications:** CONSTIPATION (lactulose used in hepatic encephalopathy)
- *MOA:** Osmotic laxatives –> Stay in the gut lumen and increase osmolarity therefore increases stool water content
- *S/E’s:** Colic/flatulence, nausea
- *CI’s:** Bowel obstruction, galactosaemia (lactulose), severe IBD
- *Interactions: -**
- *Other info:** Lactulose produces an osmotic diarrhoea of low faecal pH and discourages the proliferation of ammonia producing bacteria therefore it is used in the treatment of hepatic encephalopathy 50mL TDS causing 3 soft stools per day.
**Liquid paraffin **oral emulsion 20mL nocte
**Arachis Oil **enema 130mL warm
- *Indications:** Constipation esp with haemorrhoids/anal fissures
- *MOA:** Stool softener
- *S/E’s:** Faecal leakage, anal irritation and decreases absorption of ADEK fat soluble vitamins. Granulomatous reactions.
- *CI’s:** Under 3 year olds. Avoid prolonged use. Bowel obstruction.
- *Interactions:** -
- *Other info: **
Hyoscine butylbromide aka Buscopan
20mg QDS
- *Indications:** Symptomatic relief of GI or GU disorders characterised by smooth muscle spasm e.g in IBS, bowel colic and excessive respiratory secretions
- *MOA:** Anti muscarinic + Anti cholinergic = antispasmodic
- *S/E’s:** Anti cholinergic side effects –> Constipation, palpitations, urinary retention, pupil dilation/loss of accomodation, dry mouth, flushing
- *CI’s:** Myasthenia gravis, paralytic ileus, pyloric stenosis, toxic megacolon, BPH
- *Interactions:** TCA’s, ETOH, MAOI’s
- *Other info: **
**Mebeverine **135mg TDS before meals
**Peppermint Oil **capsules 2 TDS swallow whole
- *Indications:** IBS, diverticular disease
- *MOA:** Antispasmodic –> direct relaxant of intestinal smooth muscle, relief of colic pain in IBS
- *S/E’s:** Allergies to mebeverine reported, heartburn
- *CI’s:** Bowel obstruction/ileus
- *Interactions:** -
- *Other info:** -
Loperamide (Imodium)
4mg initially then 2mg after each loose stool for max 5 days
- *Indications:** Symptomatic relief of acute uncomplicated diarrhoea or chronic diarrhoea in adults
- *MOA:** Opiod receptor agonists –> bind to opiod receptors in GIT, slows intestinal transit. Does not cross BBB therefore no central effects.
- *S/E’s:** Nausea, flatulence, headache, dizziness
- *CI’s:** Infective diarrhoea, abdo distension, abx assoc colitis, caution in hepatic impairment
- *Interactions:** -
- *Other info:** -
**Sulfasalazine **
Mesalazine
(5-ASA)
1g QDS in acute attacks
Indications: Mild - Mod -Severe UC + remission maintenance, active Crohn’s, RA
MOA: Unknown, aminosalicylates
S/E’s: N+V+D, abdo pain. Sulfasalazine = blood dyscrasias(agranulocytosis, aplastic anaemia, leucopaenia etc), hepatitis, rashes, oligospermia, pulm fibrosis
CI’s: Salicylate hypersensitivity, caution in renal/hepatic impairment
Interactions: -
Other info:Check renal function/LFT’s/FBC before Rx, at 3 months and then annually.Advise pt to report any bleeding, bruising, fever, sore throats etc (–>blood dyscrasias, check FBC). Can use topically by suppositories in distal disease.
Infliximab (aka Remicade)
IV infusion 5mg/kg every 8weeks
- *Indications:** IBD - severe active Crohn’s, severe UC (not respnsive to steroids or conventional drugs), Ank spond, RA, Psoriasis.
- *MOA:** Chimeric monoclonal antibody against TNFalpha (prevents it binding)
- *S/E’s:** Serious infections (TB), mod/severe heart failure (CCF), CNS demyelination, allergic reactions, hepatosplenic T cell lymphoma
- *CI’s:** TB, demyelinating disorders, hx or development of malignancy, PUVA Rx in psoriasis, heart failure
- *Interactions:** Live vaccines, Abatacept
- *Other info:** Screen for TB before use. Parenteral administration.Give with hydrocortisone for decreases allergic side effects.
Adalimumab (aka Humira)
40 S/C 2 weekly
- *Indications:** IBD - severe active Crohn’s, severe UC, Ank spond, RA/JIA, Psoriasis
- *MOA:** Human monoclonal antibody against TNFalpha (blocks its action)
- *S/E’s:** Severe infections (TB), injection site reactions, GI disturbances
- *CI’s:** TB, pregnancy, demyelinating disorders
- *Interactions:** Live vaccines, abatacept
- *Other info:** By sub cut injection. Check for TB/hepatitis before use.
Azathioprine
2.5mg/kg daily PO
Steriod sparing agent/ Immunosuppressant
- *Indications:** IBD - severe Crohn’s, maintenance Crohns’s/UC, transplant rejection prophylaxis, RA, severe refractory eczema, autoimmune conditions
- *MOA:** Immunosuppressant.** **Prodrug - metabolised to 6-mercaptopurine which inhibits the synthesis of purines–> inhibiting cell proliferation
- *S/E’s: **Hypersensitivity reactions, bone marrow suppression, liver impairment, cholestatic jaundice, hair loss, increased infection risk.
- *CI’s: **Decreased thiopurine methyltransferase activity (TPMT). TPMT metabolises the drug. Increases the risk of bone marrow suppression.
- *Interactions: **Allpurinol. ACEi, Trimethoprim
- *Other info: **If absent TPMT activity do not give the drug!! Check before! Decrease the dose if renal/liver impairment. Monitor FBC weekly initially. Counsel pt to report signs of bone marrow suppression.
GORD Rx
Conservative –> Lose weight, raise head of bed, small regular meals no later than 3 hours before bed, stop smoking, decrease ETOH, avoid hot drinks and spicy foods, avoid tight clothes, stop NSAIDs/steriods/CCB’s/nitrates
Medical –>
- OTC antacids: Gaviscon/Mg trisilicate
- Full dose PPI for 4-8weeks e.g. lansoprazole 30mg OD
- No response –> double dose of PPI
- No response –> add an H2RA e.g. ranitidine 300mg nocte
Surgical –> Nissen’s fundoplication
PUD Rx
Conservative –> lose weight, stop smoking and decrease ETOH, avoid hot drinks and spicy foods, stop NSAID’s and steroids
Medical –>
- OTC Antacids - Gaviscon/Mg Trisilicate
- H.Pylori eradication - PAC500 or PMC250
- Full dose acid suppression PPI/H2RA for 4-8weeks
Surgical –> Selective vagotomy, Subtotal gastrectomy + Roux-en-Y
Ulcerative Colitis Rx
Acute Severe UC
Resus, ABC, Admit, IV fluids, NBM, Hydrocortisone IV 100mg QDS + PR, transfusion if needed, LMWH, monitoring/bloods/stool chart/AXR. If no improvement within 3 days MDT discussion, add ciclosporin. If improve swtich to oral prednisolone tapering regime + 5-ASA
Inducing Remission
Out pt Rx, Oral therapy = 5-ASA, Prednisolone, Ciclosporin/Infliximab. Topical therapy = mainly left sided disease, suppositories/enemas/foams (5-ASA + Pred). +/- steroid sparing azathioprine/infliximab
Maintaining Remission
1st line = 5-ASA PO and topical, 2nd line = azathioprine, 3rd line = Infliximab/Adalimumab
Surgery - Elective/Emergency - Proctocolectomy with end ileostomy or total colectomy. Curative treatment!!
Crohn’s Rx
Acute severe Crohn’s
Resus, ABC, Admit, IV fluids, NBM, Hydrocortisone IV 100mg QDS + PR if rectal disease, Abx Metronidazole, LMWH, Dietician review, Monitor closely. If improve switch to oral prednisolone reducing regime. If no improvement add methotrexate/infliximab + MDT review
Inducing remission
Out pt Rx, high fibre diet and vitamin supplements, 1st line = Budesonide (ileocaceal disease), Sulfasalazine (colitis). 2nd line = Prednisolone. 3rd line = Methotrexate, 4th line = Infliximab/Adalimumab
Maintaining remission
Azathioprine/Methotrexate/Infliximab
Surgery - limited resections/stricturoplasty/defunctioning temporary loop ileostomy. Up to 80% have surgery at some point. Not curative ever!
Clostridium difficile Rx
HIGH RISK Abx = Cephalosporins, Clindamycin
**Conservative - **stop causative Abx, avoid anti-diarrhoeal’s, enteric precautions, isolate/side room etc. Send stool samples to confirm by c. diff toxin assay
Medical - 1st line = Metronidazole 400mg PO TDS 10-14days 2nd line = Vancomycin 125mg PO QDS 10-14days Severe = Vancomycin 125mg PO + Metro IV
**Surgical - **May need urgent colectomy if toxic megacolon/deteriorating
Re-infection - can use repeat course of metronidazole 10-14days