Lower GI Flashcards
Lower GI
Rx list
- STIMULANT LAX: lubiprostone, linaclotide
- SALINE LAX: Mg(OH)2
- ANTI-DIARRHEAL: loperamide, alosetron
- MESALAMINE: Sulfasalizine
- CORTICOSTEROID: prednisone
- THIOPURINE ANTI-METABOLITE: Azathioprine
- TNFa INHIBITOR: Infliximab
Laxatives: MOA
- Bulk forming
- Stool surfactants
- Stimulants
- Cl channel activator
- Osmotic saline
- Osmotic sugar
- U opoid receptor blocker
- 5-HT4 blocker
- Bulk forming = UP vol+evac
- Stool surfactants= DOWN surface tension, lubricate (mineral oil)
- Stimulants = water secretion, peristalsis (bisacodyl/senna)
- Cl channel activator= lubiprostone
- Osmotic saline= Mg(OH)2
- Osmotic sugar= lactulose/PEG
- U opoid receptor blocker= alvimopan
- 5-HT4 blocker= tegaserod
Laxative effect
FECAL SOFTEN: 1-3 days = bulk-forming laxatives, stool surfactants
SOFT/SEMI-FLUID STOOL: 6 - 24 hours = Stimulant lax, anthraqiunones (senna), Cl channel activator (L+L), opioid blocker, serotonin HT4 blocker
WATERY EVAC: 1-3 hours = Sugar lax, castor oil
Lubiprostone
IBS w/ CONSTIPATION
- ClC2 CL channel activator
- UP int fluid secretion
- Minimal absorption= luminal action
- S.E.= diarrhea, nausea
Linaclotide
IBS w/ CONSTIPATION
- activate CFTR (cystic fibrosis)
- Int secretion up
- S.E. = diarrhea, NO IN PEDS (dehydration)
Saline Laxative: Mg(OH)2
- Osmotic = UP fluid + peristalsis
- cathartic dose (colonoscopy)= full evac <3 hrs
- S.E. = NO IN RENAL FAILURE (hyperMg)
Loperamide
ANTI-DIARRHEAL
- stim mu opioid receptors in intestine
- S.E. = constipation, NO Ulcerative colitis/amoebic dystentery(toxic megacolon), less CNS toxicity
IBS diarrhea
Tx
- loperamide
* alosetron (women) = 5HT3 blockade, S.E. = ischemic colitis
IBS constipation
Rx
- lubiprostone
- Mg(OH)2
ER = Tegaserod (5-HT4)
IBD
Tx
ACTIVE = Prednisone
LONG-TERM (immunosuppressive) = azathioprine
S.E. = bone marrow suppression,
(Pancreatitis, LFTs)
IBD tx stepup
NOT ON TEST
MILD = 5-aminosalycilate (sulfasalazine)
MODERATE = TNF blocker, prednisone, azathioprine
SEVERE = TNF blocker
Sulfasalazine (mesalamine)
—-> mesalamine (5-ASA) = active
*target best to sm intestine overall (sulfasalazine in colon)
Crohn’s
- Infliximab (TNFa)(also ulcerative colitis) (s.e.= infxns)
- Methotrexate
- ABX = metro, cipro (enteric balance)
