L16 Autonomic Pharmacology

Receptor Type

• Parasympathetic receptors: Nicotinic (Ganglion). Muscarinic (Post-ganglionic neurone synapse)
• Sympathetic receptors: Nicotinic (Ganglion). Adrenergic (Post-ganglionic neurone synapse)
• Alpha-1 Subtype forming nACh receptor (Skeletal muscle)
• Alpha2-7 subtypes in ACh receptors (Nervous System)
• MUSCARINIC
• ADRENERGIC
• Adrenergic Receptors(review)
• Receptor Mechanisms

Hexamethonium

• Non-Competitive - Binds to different location, inhibits function
• Blocks ALL effects of Autonomic system
• Previously, Anti-Hypertensive use - Blocks all functions including sympathetic (responsible for high BP)

Pilocarpine, Bethanechol, Cevimeline

• Muscarinic AGONIST
• Pilocarpine Ciliary Muscle M3 receptor: Reduces IOP, Increases Aq Humour drainage into Canal of Schlemm
  • Use: Glaucoma. Apply topically.
• Cevimeline Increase glandular secretion: Salivary, Lacrimal
  • Use: Sjögrens Syndrome - Autoimmune secretory

Atropine, Hyoscine, Cyclopentolate

• Muscarinic ANTAGONIST