PNS + Dementia drugs

Drugs to manage Alzheimer’s dementia

• NMDA antagonist

• cholinesterase inhibitors

NMDA antagonist drugs

memantine

NMDA antagonist MOA

MOA: NMDA receptor antagonist

cholinesterase inhibitors drugs

• Donepezil

• Rivastigmine

• Galantamine

cholinesterase inhibitors MOA

MOA: prevents acetylcholinesterase from breaking down Ach, which increases Ach levels @ the cholinergic synapses in CNS

When is the best time of the day to administer the anticholinesterase to a patient

in the evening before bedtime

Memantine ADR

ADR: caution in patients w/ moderate renal impairment

• can use w/ donepezil if modest changes in cognitive functioning

Donepezil, Rivastigmine, Galantamine ADR

ADR: n/v/d, dyspepsia, dizzy, heart attack, bradycardia (dose dependent)

Bethanechol MOA

Binds reversibly to the muscarinic receptor; no impact on the nicotine receptors

Bethanechol use

Relieving urinary retention

• esp In post op and postpartum patients

Bethanechol adverse effects

• hypotension 2nd to vasodilation

• bradycardia

• sialorrhea

• increased gastric acid secretion/abdominal cramps/diarrhea

• increased bladder pressure

• asthma exacerbation

• dysrhythmias in patients w/ hyperthyroidism 

Oxybutynin uses + ADR

• Overactive bladder; urgency incontinence where detrusor contracts when it should not

• Dry mouth, constipation, tachycardia

Atropine MOA

competitively antagonizes ACH actions & other cholinergic agonists @ the muscarinic receptors

uses of atropine

• Bradycardia

• Pre-op reduction of secretions

• Blockage of cardiac vagal reflexes

• Peptic ulcer disease

• GI disorders

• Muscarinic agonist poisoning (mushrooms)

• Organophosphate poisoning

• Ophthalmic preparations to produce mydriasis 

• Cycloplegia (pupillary dilation in acute inflammation of iris & uveal tract)

Atropine adr

urinary retention; very drying effects. this is for atropine

atropine contraindications

• Glaucoma (increased intraocular pressure)

• Asthma (increased thick airway secretions)

• Intestinal atony

• Urinary obstruction

• Tachycardia

Atropine antidote

Physostigmine

Scopolamine use

Motion sickness

Motion sickness route

72-hour transdermal patch

Stigmine uses

• Myasthenia gravis

• reversal of competitive neuromuscular blockade

Stigmine antidote

• Atropine: for excessive muscarinic stimulation

• Mechanical ventilation: for respiratory depression

Stigmine ADR

• Sialorrhea

• increase in gastric secretions

• increased tone/mobility of GI (diarrhea)

• urinary urgency, bradycardia

• sweating, miosis

• spasm

Sludge