P3 Pharma (PNS drugs)

Carbachol

Used to induce miosis & treat narrow-angle glaucoma

Carbachol

What direct agonist drug activates both muscarinic & nicotinic receptors

Carbachol

It is a quaternary compound that has a carbamic-acid ester

Bethanechol

What drug only activates muscarinic receptors and is more resistant to cholinesterase

Bethanechol

What drug is administered SQ to increase bladder contractility in small animals

Bethanechol

What drug is not absorbed in the GI tract when taken orally

patients with urinary outflow obstruction, Gl obstruction, asthma, and hypotension.

Bethanechol shouldn't be used in patients with what underlying conditions?

Pilocarpine

What drug is a tertiary amine that acts on muscarinic receptors only

Pilocarpine

What drug is rarely used as an opthalmic sol’n to induce miosis and decrease intraocular pressure like glaucoma

Pilocarpine

What drug is taken orally as a primary treatment of neurogenic keratoconjunctivitis sicca in dogs

local irritation and inflammation of the uveal tract and may cause systemic effects on repeated use

What are the adverse effects of Pilocarpine

Methacholine

It is a quaternary ammonium compound muscarinic receptor agonist with long duration of action

Methacholine

Drug used to diagnose asthma & bronchial hyperreactivity

Methacholine Challenge Test

What do u call the test that uses methacholine in diagnosing asthma & bronchial hyperreactivity

Cholinesterase inhibitors/Indirect agonists

These agents act indirectly by preventing the hydrolysis of ACh by acetylcholinesterase (AChE)

1. Reversible AChE inhibition

2. Carbamylation of AChE

3. Phosphorylation of ACHE

Give the MOA of cholinesterase inhibitors

Physostigmine

This drug is a tertiary amine that mimics the effect of ACh.

Physostigmine

This drug is used topically to treat simple and secondary glaucoma

Physostigmine

This drug is used for the adjunctive treatment of ivermectin toxicity in dogs

Physostigmine

This drug is used as a provocative agent for the diagnosis of narcolepsy in dogs and horses

Physostigmine

This drug is used as treatment for anticholinergic toxicity (atropine/scopolamine)

Neostigmine

This drug contains quaternary ammonium with similar effects to physostigmine.

Neostigmine

This drug is used for rumen atony, Gl peristalsis, bladder emptying, and skeletal muscle stimulation in livestock

Neostigmine

This drug is used in treating non-depolarizing neuromuscular blocking agents (curare-type) overdoses in dogs and ivermectin overdoses in cats

Neostigmine

This drug is used in the diagnosis and treatment of myasthenia gravis

Tensilon Test/ Edrophonium Test

What do u call the test that's used for diagnosing myasthenia gravis

Pyridostigmine

This drug has similar to neostigmine and has the longest duration of action (4-6 hours)

Pyridostigmine

What drug is used orally for the long-term treatment of myasthenia gravis in dogs and cats (rarely)

At the GI tract

Where is Pyridostigmine marginally absorbed

Edrophonium

This drug is identical with neostigmine but has the shortest duration of action (10-15 minutes).

Edrophonium

This drug is used in Tensilon Test for the diagnosis (only) of myasthenia gravis and for antagonizing tubocurarine-like drugs.

Edrophonium

Drug used to reverse supraventricular arrhythmias

Parenteral

Edrophonium is only given thru what route

Echothiophate

Thus drug is a quaternary organophosphate (OP) with long duration of action (>12hrs)

Echothiophate

What drug is used topically to treat open angle glaucoma

Carbamate poisoning

This results from the excessive inhibition of AChE by carbamates which is reversible in nature

Atropine

What is given to reverse the effects of Carbamate poisoning

Organophosphate poisoning

This results from the excessive inhibition of AChE by organophosphates which is irreversible in nature due to "aging" of the enzyme

Atropine + Pralidoxime (2-PAM)

What can reverse the effects of organophosphate poisoning if aging has not occurred yet.

Paralyze muscles by disrupting the transmission of nerve impulses from motor nerves to skeletal muscle fibers

What's the function of Neuromuscular blockers

Nicotinic Receptor, specifically N1

What receptors do NMBs act on

1) facilitiates endotracheal intubation

2) promote & enhance muscle relaxation during surgery

What are the therapeutic uses of NMB

1) flaccid paralysis

2) prolonged apnea

What are the adverse effects of NMBs

Cholinesterase inhibitors

What's the antidote for non-depolarizing NMB

Because the ones that are available are only short-acting

Why does the depolarizing NMB does not need an antidote

Succinylcholine

It is an ultrashort-acting muscle relaxant

Succinylcholine

Used as a short-term muscle relaxant to aid in endotracheal intubation & lessen convulsions

Uncoordinated muscle contraction leading to muscle soreness, malignant hyperthermia, myoglobinuria

Adverse effects of succinylcholine

Tubocurarine

It is the prototype of all non-depolarizing NMBs

Because of its stong histamine release & ganglionic blockade

Why is Tubocurarine now rarely used

Atracurium

This is ¼ to ⅓ more potent than Pancuronium

Pancuronium

It is a long-acting NMB that causes vagolytic effects, tachycardia

Atracurium

This has a faster onset than Pancuronium but is eliminated via Hofmann elimination

Vecoronium

An intermediate-acting NMB that's 3x more potent than Pancuronium

Vecoronium

An NMB that's preferrably used to patients with heart conditions due to ita minimal cardiovascular effects

Rocuronium

An NMB with a rapid onset, often used as an alternative to Succinylcholine for rapid sequence intubation