cholinergic receptor-activating drugs

Question 1

glaucoma

Answer 1

• pilocarpine (direct-acting muscarinic) –> contraction of ciliary muscle
• physostigmine (indirect- acting)
  
  • phys for eyes
• echothiophate (indirect-acting)

Question 1

treatment for direct-acting compound toxicity

Answer 1

atropine (muscarinic antagonist)

Question 2

AChE inhibitors

Answer 2

• Neostigmine
• Physostigmine
• Edrophonium
• Echothiophate (these are all eye drugs- glaucoma or MG)
• Soman
• Donepizil
• ** PAM rescues AChE from the inhibition of these drugs (ie: if poisoned with soman, PAM will regenerate phosphorylated AChE

Question 3

Toxicity (of both direct and indirect-acting)

Answer 3

SLUDGE salivation, lacrimation, urination, defecation, GI distress, emesis

Question 4

dry mouth (ie: in Sjorgren’s syndrome)

Answer 4

cevimeline (direct-acting muscarinic) –> increases salivation

“sss”: cevimeline and salivation/sjogren

Question 5

organophosphate cholineseterase inhibitors

Answer 5

Soman and Echothiophate

Question 6

direct vs indirect acting drugs

Answer 6

• direct agonists: act directly on muscarinic or nicotinic ACh receptor
  
  • tend to have “chol” in name
• indirect: inhibit ACh Esterase
  
  • tend to have “stigmine” in name

Question 8

Alzheimer’s

Answer 8

Donepezil (indirect-acting)

think “z”

Question 9

treatment for indirect-acting compound toxicity

Answer 9

atropine and PAM

(atropine will immediately buffer ACh overload while PAM rescues AChE)

Question 10

myasthenia gravis

Answer 10

• autoimmune attack on nicotonic receptors –> impaired neurotransmission of ACh
• neostigmine (indirect-acting) –> overdosing causes depolarization block
• edrophonium (indirect-acting) –>used as dx tool bc of short half-life
• pyridostigmine (indirect-acting)
• see p 114 for reference

**stigmine= indirect

Question 11

post-op and neurogenic ileus and urinary retention

Answer 11

• bethanechol (direct-acting)
  
  • activates bowel and bladder smooth muscle
  • B for bowel and bladder
• neostigmine (indirect-acting)

Question 12

pilocarpine

Answer 12

• direct- acting muscarinic
• glaucoma (activates contraction of ciliary mm of eye to improve drainage)

Question 13

physostigmine

Answer 13

• indirect acting cholinomimetic (AChE inhibitor)
• glaucoma

Question 14

echothiophate

Answer 14

• indirect acting cholinomimetic (AchE inhibitor)
• glaucoma

Question 15

neostigmine

Answer 15

• indirect acting cholinomimetic (AchE inhibitor)
• myasthenia gravis and neurogenic ileus and urinary retention

Question 16

edrophonium

Answer 16

• indirect acting cholinomimetic (AChE inhibitor) –> very short acting
• diagnostic in myasthenia gravis (in underdosed PT muscle strength will increase when you add edrophonium; in overdosed PT there will be no affect when you add edrophonium)

Question 17

Bethanechol

Answer 17

• direct-acting Muscarinic
• post-op and neurogenic ileus, urinary retention

Question 18

Muscarine

Answer 18

• direct-acting muscarinic

Question 19

nicotine

Answer 19

direct-acting NICOTINIC