Constipation E2

Question 1

What are the potential causes of constipation including medications and/or comorbidities?

Answer 1

Medications: Opioids | Anticholinergics (TCAs, Antihistamines, Antipsychotics) | Iron | Calcium Channel Blockers

Lack of Fiber/Low H2O intake (increase fiber gradually)

Comorbidities: IBS, Pregnancy, Hypothyroidism

Question 2

How do we treat acute constipation where a patient desires immediate evacuation of the bowel?

Answer 2

This is typically treated by using an enema or suppository.

1st Line: Stimulant Laxatives or Osmotic Laxatives.

Example: Bisacodyl Suppository

Question 3

How do we typically manage chronic constipation?

Answer 3

1st Line = Metamucil (Bulk-Forming Laxative)

2nd Line= Osmotic Laxative or Stimulant Laxatives

Question 4

Miralax (Generic, Class)

Answer 4

Polyethylene Glycol
Osmotic Laxative

Question 5

Lactulose

Answer 5

Rx Only
Osmotic Laxative
PO
Non-absorbed sugar pulls water into the colon.

Question 6

Constipation definition

Answer 6

</= 3 bowel movements/week

Question 7

How do we manage chronic idiopathic constipation?

Answer 7

Options: Amitiza and Gaunylate Cyclate Receptor Agonist (Linzess and Trulance)

Question 8

Amitiza (Generic, Mechanism,Indication, ADE)

Answer 8

Lubiprostone
Acts on CL channels –> increase CL secretion into feces which pulls water in.

Used to treat Chronic Idiopathic Constipation

ADE: 20% of patients develop diarrhea/nausea

Question 9

Guanylate Cyclase Agonist Mechanism

Answer 9

Increase CL and Bicarbonate secretion into the stool which increase the liquidity to treat chronic idiopathic constipation.

Question 10

What are the guanylate cyclase agonists?

Answer 10

Linzess (Linaclotide)
Trulance (Plecanatide)

Question 11

Linzess (Generic, Class)

Answer 11

Linaclotide
Guanylate Cyclase Agonist

Question 12

Trulance (Generic, Class)

Answer 12

Plecanatide
Guanylate Cyclase Agonist

Question 13

How do we treat opioid-induced constipation?

Answer 13

1st Line = Osmotic Laxatives
2nd Line = Stimulant Laxatives (Bisacodyl or Senna)

Should be noted, that we typically need a stimulant laxative to counteract the lack of bowel contraction. However, we should still start with an osmotic laxative.

If needed mu-receptor agonists or amitiza may also be used.

Question 14

Bisacodyl

Answer 14

Stimulant Laxative

Question 15

Senna

Answer 15

Stimulant Laxative

Question 16

How should stimulant laxatives be taken?

Answer 16

At night to minimize cramping.

Question 17

Relistor (Generic, Class)

Answer 17

Methylnaltrexone
Mu receptor antagonist

Question 18

Movantik (Generic, Class)

Answer 18

Naloxegol
Mu Receptor Antagonist

Question 19

Symproic (Generic, Class)

Answer 19

Naldemidine
Mu Receptor Antagonist

Question 20

Mu Receptor Antagonist Warning

Answer 20

1. Severe Abdominal Pain + Diarrhea –> D/c If occurs
2. Bowel Perforation –> CI in GI malignancy, Diverticulitis, IBS

Question 21

Mu Receptor Antagonist CI

Answer 21

1. GI malignancy
2. Diverticulitis
3. IBS