Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
21 Cards in this Set
- Front
- Back
|
What are the 4 types of laxatives? |
- Bulk laxatives - Osmotic laxatives - Faecal softeners - Stimulant laxatives |
|
|
Name some bulk laxatives |
The most important bulk laxatives are dietary fibres containing lignin or cellulose, semisynthetic compounds like methylcellulose or agar. |
|
|
What is the mechanism of action of bulk laxatives? |
Bulk laxatives are non-digestible compounds, so they will add bulk to the stool. The increased bulk promotes peristalsis. |
|
|
Name some osmotic laxatives |
- Lactulose - Macrogols - Non-absorbable salts like sodium phosphates and certain magnesium salts |
|
|
What is the mechanism of action of osmotic laxatives? |
Sodium sulphate, certain magnesium salts and lactulose are poorly absorbed but osmotically active, so they will trap water in the lumen. Macrogols are comprised of polyethylene glycol, which is osmotically active and not absorbable. |
|
|
Name some faecal softeners. |
Docusate (Klyx) and liquid paraffin. |
|
|
What is the mechanism of action of faecal softeners? |
Faecal softeners emulsify and soften the stool. |
|
|
Name some stimulant laxatives |
Bisacodyl (Dulcolax) and Senna glycosides. |
|
|
What is the mechanism of action of stimulant laxatives? |
They stimulate the myenteric plexus, resulting in increased peristalsis. |
|
|
What three types of drugs can be used as antidiarrhoeal agents? |
- Antimotility agents - drugs that inhibit peristalsis - Adsorbents - Dietary fibres |
|
|
Name some antimotility agents |
Loperamide, diphenoxylate, mebeverine, anticholinergic agents |
|
|
What is the mechanism of action of loperamide and diphenoxylate? |
Loperamide and diphenoxylate are peripherally acting opioids. |
|
|
Which drugs are used in the treatment of inflammatory bowel diseases?
|
- Corticosteroids like prednisolone - Immunosuppressants like azathioprine, mercaptopurine, methotrexate - 5-ASA drugs like mesalazine, sulphasalazine - Biological therapy like infliximab, adalimumab |
|
|
Which drug can be used to dissolve cholesterol stones? |
Ursodeoxycholic acid |
|
|
Which opioid can be used as analgesic for biliary colic? |
Buprenorphine
|
|
|
What is the mechanism of action of buprenorphine, and why is it appropriate as an analgesic for biliary colic? |
Buprenorphine is an opioid which has µ agonist and κ and δ antagonist effects. This gives opioid-like analgesia but doesn’t cause the opioid-induced constriction of the sphincter of Oddi. |
|
|
Name 2 pancreatic enzyme supplements. |
Pancreatin, pancrelipase |
|
|
Which drugs are used to treat hepatic encephalopathy? |
Lactulose and broad-spectrum non-absorbable antibiotics like neomycin and rifaximin. |
|
|
How does lactulose improve hepatic encephalopathy? |
Lactulose decreases the pH of the gastrointestinal lumen. This causes ammonia (NH3) to be converted to its corresponding base, ammonium (NH4+). This compound is less absorbed and less toxic. |
|
|
How are 5-ASA drugs administered? |
orally or rectally as suppositories or enemas. |
|
|
How are infliximab and adalimumab administered? |
as subcutaneous injections every 2 weeks. |
