Lower GI Drugs

Question 1

Contraindications for laxatives

Answer 1

Cramps
Colic
n/V
Appendicitis
Undiagnosed abdominal pain

Question 2

Lubriprostone

Answer 2

IBS w/ constipation
MOA: ClC2 Cl channel activator - increases intestinal fluid secretion 
Acts luminally (minimal absorption)

Question 3

Linaclotide

Answer 3

IBS with constipation
CTFR activator - inc intestinal fluid secretion
Acts luminally
CONTRA IN PEDS D/T DEHYDRATION

Question 4

Mg(OH)2

Answer 4

Saline laxative
Hypertonic, osmotic P leads to accumulation of fluids in GI tract and stim of peristalsis
Cathartic dose in colonoscopy prep
RENAL INSUFF = MG+++

Question 5

Loperamide (imodium)

Answer 5

MOA: mu opioid stim slows intestinal transit time
Contra: UC/dysentery = toxic mega colon

Question 6

Tx for IBS with diarrhea

Answer 6

Loperamide
Muscarinic antagonists
Alosetron

Question 7

Alosetron

Answer 7

Restricted use drug - women
5HT3 antagonist
Decreased colon motility
AE: ischemic colitis which can be fatal

Question 8

Tx for IBS with constipation

Answer 8

Mg(OH)2

Emergency only: tegaserod

Question 9

Tx for acute episode of IBD

Answer 9

Prednisone to decrease inflammation response (short term)

Question 10

Long term treatment for IBD

Answer 10

Immunosuppressive such as azathioprine or 6 mercaptopurine

Can lead to bone marrow suppression

Question 11

UC treatment

Answer 11

Sulfasalazine (contains 5ASA)
Topical, not systemic
AE: 40% of patients cannot tolerate d/t sulfapyridine moeity

Question 12

Crohn’s tx

Answer 12

Infliximab
Antibody to TNF-alpha
AE: increased infections

Can also give metronidazole, cipro