Module 2 Drugs
Myasthenia Gravis and Alzheimers
Cholinesterase Inhibitors - Neostigmine
MOA - Cholinesterase inhibition causes an increase in ACh at the neuromuscular and central synapses at the NMJ
Indications - Myasthenia fravis treatment; edrophonium - reversal of non-depolarizing neuromuscular blockers
Adverse Effects - Cholinergic crisis
Risks - GI obstruction, Asthma, Bradycardia
RN Implications - Individualized sosing; medical alert bracelet; differentiate myasthenic vs cholinergic crisis
Other drugs in class: Phsostigmine, Edrophonium, Pyridostigmine
Central Cholinesterase Inhibitors - Donepezil
MOA - Centrally selective cholinesterase inhibition causes an increase in ACh in the brain
Indications - Mild to moderate Alzheimer’s
Adverse Effects - N/V/D, dizziness, bradycardia, syncope
Risks - Caution with bradycardia, COPD/asthma
RN Implications - Safety for falls; HR monitoring; Nighttime dosing to minimize GI upset
Other drugs in class:
Parkinson’s Disease
Dopamine synthesis - Levodopa/Carbidopa
MOA - Increases dopamine in the CNS; prevents peripheral breakdown, so more Levodopa reaches the brain and causes fewer side effects
Indications - Treatment fo bradykinesia, rigidity, tremor
Adverse Effects - Discoloration of urine/sweat
Risks - CV effects, psychosis, “on-off”, wearing off
RN Implications - High-yield food, avoid large doses of pyridoxine-rich foods; spread protein intake throughout the day; monitor for dyskinesias -> may need amantadine or dose adjustment; Timing “on” periods for PT/ADLs - report worsening on-off to provider
Other drugs in class: none
Dopamine Agonists - Pramipexole
MOA - Stimulates dopamine receptors
Indications - early PD monotherapy
Adverse Effects - Daytime sleep attacks, hallucinations, orthostatic hypotension, impulse control disorders
RN Implications - Screen for compulsive behaviors; caution about driving; counsel the family to watch for personality changes
Other drugs in class: Ropinrole, Apomorphine, Rotigotine
Dopamine Releaser - Amantadine
MOA - smooths out dopamine release; increases dopamine release, decreases reuptake
Indications - reduced levodopa-induced dyskinesias
Adverse Effects - confusion, dizziness, Insomnia
Risks - Livedo reticularis
RN Implications - reassure about reversible skin changes; safety for falls; avoid activities requiring high alertness early in therapy
Other drugs in class: none
COMT Inhibitors - Entacapone
MOA - Inhibits COMT, causing prolonged levodopa action by decreasing peripheral breakdown
Indications - adjunct to levodopa/carbidopa
Adverse Effects - GI upset, Dyskinesias, Orthostatic Hypotension
Risks - Urine discoloration; Tolacpone hepatotoxicity
RN Implications - LFT monitoring if talcopne used; teach harmless urine discoloration
Other drugs in class: Tolcapone
MAO-B - Inhibitors - Selegiline
MOA - Inhibits MAO-B, causing decreased dopamine breakdown
Indications - Early PD or adjunct to levodopa to reduce “wearing off.”
Adverse Effects - Insomnia, N/V
Risks - Hypertensive crisis with tyramine foods; Interaction with merperidine, SSRIs, other MAOIs
RN Implications - Give no later than noon; Tyramine avoidance 2 weeks after stopping; review the med list carefully
Other drugs in class: Rasagiline
Anticholinergics - Benzotropine
MOA - Muscarinic blockade causes decreased tremor and muscle rigidity
Indications - PD tremor; drug-induced EPS
Adverse Effects - Anticholinergic symptoms
Risks - Glaucoma, BPH, and Elderly Delirium risk
RN Implications - I&O; fiber and fluids; eye pressure monitoring; avoid in older adults with confusion
Other drugs in class: trihexyphenidyl
Seizure Disorders
Barbiturate AEDS - Phenobarbital
MOA - increases GABA, causing a strong CNS depression
Indications - Tonic Clonic and Partial seizures
Adverse Effects - Sedation, Cognitive Impairment
Risks - dependence, respiratory Depression, Toxicity
RN Implications - Avoid other CNS Depressants; taper slowly; monitor for respiratory and cardiac depression
Other drugs in class: Primadone
Hydantoins - Phenytoin
MOA - Na channel slowing -> reduced seizure spread
Indications - tonic-clonic and partial seizures
Adverse Effects - CNS (Nystagmus, Ataxia); Gingival hyperplasia, rash
Risks - Dysrhythmias, Hypotension; teratogenic; narrow TI
RN Implications - Slow IV rate, large vein; Good oral hygiene, folic acid; monitor warfarin and OCP levels; Monitor for rash
Other drugs in class: Fosphenytoin
Carbamasepine
Indications - Focal and tonic-clonic seizures, bipolar, and trigeminal neuralgia
Risks - Blood dyscrasias; SJS/TEN; Hypo-osmolarity/SIADH
RN Implications - CBC baseline and trend; monitor NA+ and fluid status; avoid grapefruit Juice; stop if rash appears
Valproic Acid
Indications - Broad-spectrum seizures, bipolar disorder, migraines
Risks - hepatotoxicity; pancreatitis; thrombocytopenia; teratogenic
RN Implications - LFTs, Amylase, platelets; report abdominal pain, jaundice, easy bruising
Succinimides - Ethosuximide
MOA - Reduced T-type calcium currents in thalamic neurons
Indications - Absence seizures only
Adverse Effects - GI upset, sleepiness, fatigue
Risks - Rare SJS, Blood Dyscrasias
RN Implications - Give with food; monitor for bruising; safety precautions for drowsiness
Other drugs in class: none
Sodium-Channel Modulator - Lamotrigine
MOA - Inhibits glutamate release
Indications - Seizures, bipolar depression
Adverse Effects - dizziness, blurred vision, headache, N/V
Risks - SJS/TEN, Aseptic Meningitis, suicidality when starting
RN Implications - Slow titration; caution if also on valproate
Other drugs in class: none
SV2A Modulator - Levetiracetam
MOA - Modulates SV2A to reduce neurotransmitter release
Indications - partial seizures, tonic-clonic, myoclonic
Adverse Effects - dizziness, asthenia, fatigue, agitation
Risks - Mood changes, Suicidality
RN Implications - Screen for underlying depression/anxiety; Fewer drug interactions than many AEDs; Seizure diary encouraged
Other drugs in class: Brivaracetam
GABA enhancer + Glutamate Antagonist - Topiramate
MOA - Enhances GABA, blocks sodium channels, antagonizes glutamate receptors
Indications - Seizures, Migraine prophylaxis
Adverse Effects - Somnolence, cognitive slowing, weightloss
Risks - Metabolic acidosis; decreased sweating/increased body temperature; angle-closure glaucoma; Teratogenic
RN Implications - Monitor Bicarbinate; hydration teaching, report eye pain/ vision changes urgently; avoid overheating
Other drugs in class: none
Sodium-Channel Modulator - Oxcarbazepine
MOA - Na Channel blockade
Indications - Partial Seizures
Adverse Effects - dizziness, somnolence, N/V, ataxia
Risks - hyponatremia; SJS/TEN; Hypothyroidism; Multiorgan hypersensitivity
RN Implications - Monitor sodium; screen for rash, assess confusion/fatigue; backup contraception; watch for edema or signs of hypersensitivity
Other drugs in class: eslicarbazepine
Gabapentinoids - Gabapentin
MOA - Binds α2δ calcium channels, causing a decrease in excitatory neurotransmission
Indications - neuropathic pain, partial seizures, fibromyalgia
Adverse Effects - Somnolence, dizziness, peripheral edema, weight gain
Risks - Pregabalin; Angioedema; abuse potential
RN Implications - Avoid alcohol/CNS depressants; monitor weight and edema; teach to report facial/lip swelling immediately; caution with driving
Other drugs in class: Pregabalin
Emergency Seizure Management
MOA - Enhances GABA, causing a rapid CNS depression
Indications - Status Epilepticus; prolonged tonic-clonic seizure
Adverse Effects - Respiratory depression; hypotension
Risks - Airway compromise; Apnea with repeated dosing
RN Implications - Firstline - IV lorazepam or Diazepam; Load with fosphenytoin/phenytoin; Maintain Airway; Establish IV access; Document duration, triggers, motor activity progression
Other drugs in class: Lorazepam, Diazepam