Pharmacology Exam #1: Cholinergic Antagonists

cholinergic antagonists

agents that bind to M or N AChRs + prevent effects of ACh

antimuscarinic agents

• block mAChRs at postganglionic NMJ (PSNS)

• little/no action at skeletal NMJ/autonomic ganglia

• opposite of SLUDGEBAM

Atropine

• heart effects

• mydriasis (pupil dilation)

• bradycardia

• cholinergic agonist antidote

• DOA: 4-6 hours

Cyclopentolate

• mydriasis (pupil dilation)

• cycloplegia (temporary eye muscle paralysis)

• DOA: 6-24 hours

Tropicamide

• mydriasis (pupil dilation)

• cycloplegia (temporary eye muscle paralysis)

• DOA: 6-7 hours

Ipratropium

• SAMA

• maintenance tx for COPD

• acute asthma tx

Glycopyrrolate

• LAMA

• maintenance tx COPD

• treats airway blockages

Tiotropium

• LAMA

• maintenance tx COPD

• asthma tx

Aclidinium

• LAMA

• maintenance tx COPD

• prevents bronchospasms

Trihexyphenidyl

• M1

• Parkinson’s tx

• preferred for muscle relaxation

Benztropine

• M1

• Parkinson’s tx

Solifenacin

• M3

• overactive bladder tx

• “SOFTT blaDder”

Oxybutynin

• M3

• overactive bladder tx

• “SOFTT blaDder”

Festoterodine

• M3

• overactive bladder tx

• “SOFTT blaDder”

Tolterodine

• M3

• overactive bladder tx

• “SOFTT blaDder”

Trospium

• M3

• overactive bladder tx

• “SOFTT blaDder”

Darfenacin

• M3

• overactive bladder tx

• “SOFTT blaDder”

Scopolamine

• prevents motion sickness → typically in the form of a patch

• post op nausea/vomiting tx

Nicotine

• ganglionic blocker

• dose dependent

• complex effects

• smoking cessation

neuromuscular blocking agents (NMBs) - non-depolarizing

• block ACh at nAChRs

• [low] prevent skeletal muscle contraction, reversible by cholinesterase inhibitors

• [high] cholinesterase inhibitors CANNOT reverse

• CANNOT cross BBB

Cisatracurium

• mechanical ventilation in multisystem organ failure

Mivacurium

• eliminated by plasma cholinesterase

• calm muscles during surgery + for ventilation

• preferred drug d/t rapid onset + longer duration

Pancuronium

• excreted unchanged

• calm muscles during surgery + for ventilation

Rocuronium

• deacetylated in liver

• excreted unchanged in bile

• rapid onset ~60 seconds

• DOA: 30-60 minutes

Vecuronium

• deacetylated in liver

• excreted unchanged in bile

• slower onset → used for longer procedures

• DOA: 20-40 minutes

neuromuscular blocking agents (NMBs) - depolarizing

• constant receptor stimulation

• useful for rapid intubation

Succinylcholine

• rapid onset, short DOA

• skeletal muscle relaxant

• AE: hyperthermia, apnea due to paralysis of diaphragm, hyperkalemia

HRBMD

• Hot as a hare → increased temp due to decreased sweating

HRBMD

• Red as a beet → flushing (skin, decreased sweating)

HRBMD

• Blind as a bat → mydriasis (pupil dilation)

HRBMD

• Mad as a hatter→ delirium/confusion

HRBMD

• Dry as a bone → dry mouth/eyes, decreased secretions