Drugs used in disorders of the bowel Flashcards

Question

Sulfasalazine

Answer 1

Split by colonic bacteria into sulfapyridine and 5-aminosalicylic acid (5- ASA, mesalazine). 5-ASA believed to be responsible for beneficial effect. * Sulfapyridine absorbed, metabolised in the liver and excreted via the urine. * Most of 5-ASA eliminated unchanged in the faeces

Answer 2

Prescriber’s points: * Monitor blood counts, hepatic function, urea and electrolytes with chronic therapy * GI adverse effects can be alleviated by a drug holiday and starting at a lower dose * Gastric irritation may be minimised by taking after meals, full glass of water, enteric coated tablets * Report sore throat, fever or easy bruising – indicated heamotologic abnormalities (thrombocytopenia, granulocytopenia, red cell haemolysis

Answer 3

Immunosuppressants e.g. azathioprine, mercaptopurine, methotrexate PLUS (if necessary) Tumour necrosis factor – α inhibitors (TNF-α inhibitors) e.g. infliximab, adalimumab

Answer 4

A reduction in normal bowel habit accompanied with more difficult defecation and/or hard stools

Answer 5

Very common, especially in the elderly Causes: sedentary lifestyle, ↓ fluid intake, poor nutriƟon, avoidance of fibrous foods, chronic illness, pregnancy, drugs, chronic use of enemas & laxatives, old age, ignoring the urge Women more likely than men Late pregnancy (40%)

Answer 6

Normal function of large intestine = remove water and various salts from colon, drying and expulsion of faeces

Answer 7

Constipation.

Answer 8

Anorectal problem; constipation usually secondary to the suppression of Anorectal problem; constipation is usually secondary to the suppression of defecation, because it induces pain

Answer 9

Bright red = haemorrhoids / tear in anal canal Blood mixed with stool = refer Stool appear black and tarry = upper GI bleed

Answer 10

duration >/= 6 weeks

Answer 11

Medicine-induced constipation IBS Pregnancy Functional causes in children Depression Colorectal cancer Hypothyroidism Bowel obstruction

Answer 12

Dietary:↑ fibre & water intake – 3-5 days Avoid caffeinated drinks and diuretics Lifestyle: ↑ exercise Encourage regular bowel habits Discourage continuous use of laxatives

Answer 13

Bulk-forming-Softening and increasing feacal mass, increased bulk encourage peristalsis (mimic ↑ fibre consumpƟon) drugs Ispagula* (psyllium) (Agiobulk®, Fybogel®) * Methylcellulose * Sterulia (Normacol®) Contact/irritant--↑ GI moƟlity by directly stimulating colonic nerves Senna* (Senokot®, Soflax®) * Sodium picosulphate (metabolised by colonic bacteria to active metabolite bisacodyl) * Bisacodyl (Dulcolax® supps & enteric coated). Osmotically acting---Withdraw fluid into the bowel by osmosis drugs Lactulose* * Magnesium sulphate / hydroxide * Polyethylene glycol combinations* (Movicol®, Go-lytely®, Klean-Prep®) * Sodium phosphate* (Colo-pre

Answer 14

Non-habit-forming, supplements to dietary fibre * Indications: constipation, IBS, diverticular disease * Onset of action: 12-72 hours * Contraindications: intestinal obstruction, stenosis, ulceration or adhesions in the GIT * Caution: sodium-containing product, increase fluid intake to avoid intestinal compaction * Pregnancy √ (safe) * Drug interactions: may interfere with absorption of certain drugs (take 3 hours before or after other drugs) * Adverse effects: flatulence & abdominal distension.

Answer 15

ndications – can precipitate chronic colonic changes * Onset of action: 8-12 hours * Pregnancy – avoid * ! Abuse as slimming aid * Adverse effect: abdominal cramps, long term use Bisacodyl and Sodium picosulphate * Indicated for single dose administration to evacuate bowel in preparation for examinations of the colon (including radiological examinations) or to evacuate barium from the GIT after radiological examination

Answer 16

Onset of action: 12-72 hours * Generally used for acute and rapid evacuation of the bowel (except lactulose), prolonged use not recommended * Indications: bowel preparation for colonoscopy / colon surgery / radiological examination should receive split dose preparations, significantly improve bowel cleansing. Administer half the evening before the procedure and the other half on the morning (4-6 hours) before the procedure * Polyethylene glycol combinations include Go-Lytely® and Klean-Prep® * Sodium phosphate include Colo-Prep®

Answer 17

* Suppositories * Bisacodyl, * Glycerol (osmotic effect softens and lubricates faeces, mildly irritant effect causing rectal contraction, evacuation usually within 30 minutes) * Enemas * Sodium phosphate

Answer 18

Most common problem affecting the anorectal region Varicose veins of the ano-rectal area. Is usually accompanied by a history of constipation. In older patients consider a diagnosis of underlying carcinoma. GENERAL MEASURES High-fibre diet. Counsel against chronic use of laxatives. Avoid straining at stool

Answer 19

Bismuth subgallate compound, ointment, topical, applied 2–4 times daily OR Bismuth subgallate compound suppositories, insert one into the rectum 3 times daily. OR Lidocaine 2%, cream, topical, applied before and after each bowel action.

Answer 20

Painful small cracks just inside the anal margin, sometimes a linear ulcer. It is often seen together with a sentinel pile or external haemorrhoids. May cause spasm of the anal sphincter. May cause bleeding on defecation. Dietary advice – promote soft stools