Direct Acting Muscarinic Agonist (Cholinomimetic Drugs)

Question 1

What is the MOA of direct acting muscarinic agonists?

Answer 1

Bind to and activate muscarinic (and nicotinic)
receptors with different selectivity

Question 2

What are the clinical uses of direct acting muscarinic agonists? How do they work?

Answer 2

Postoperative ileus: Increasing secretory and motor activity of the gut

Urinary retention: Stimulate the detrusor muscle to contract

Xerostomia (dry mouth due to Sjogren’s Syndrome & Head and Neck irradiation)

Glaucoma (increases intraocular pressure): Contraction of the ciliary and pupillary constrictor muscle facilitates drainage of fluid

Question 3

What are the clinical uses of direct acting muscarinic agonists?

Answer 3

Postoperative Ileus
Urinary retention
Glaucoma
Xerostomia
Sjogren’s Syndrome
Head and Neck Irradiation

Question 4

What are the adverse effects of direct acting muscarinic agonists?

Answer 4

General cholinomimetic effects
* GIT: diarrhea, abdominal cramps, nausea/vomiting
* Urinary urgency
* Vision problems

Question 5

What are the contraindications of direct acting muscarinic agonists?

Answer 5

Asthma/ COPD (Chronic Obstructive Pulmonary Disease)
Urinary or GI tract obstruction