Neurology Pharm Flashcards
How do glaucoma drugs work
Dec. IOP via dec. amount of aqueous humor (inhibits synthesis/secretion or inc. drainage)
alpha-agonists
Epinephrine, Brimonidine (alpha2)
beta-blockers for glaucoma side effects
No pupillary or vision changes
acetazolamide glaucoma side effects
no pupillary or vision changes
What beta blockers are used in glaucoma
Timolol, betaxolol, carteolol
What duretics used for glaucoma
Acetazolamide
What alpha agonists used in glaucoma
epinephrine, brimonidine
What cholinomimetics used in glaucoma
Direct: pilocarpine, carbachol
Indirect: Physostigmine, echothiophate
What is latanoprost
Prostaglandin PGF2alpha, darkens color of iris
How do the glaucoma drugs work
The alpha agonists, beta blockers, diuretics all decrease aqueous humor synthesis.
Cholinomimetics and prostaglandin increase aqueous humor outflow.
Delta opioid receptor ligand
enkephalin
Kappa opioid receptor ligand
dynorphin
Opiates MOA on ion channels
open K+ channels, close Ca2+ channels, decerase synaptic transmission. inhibit ACh, NE, 5-HT, glutamate, substance P.
Diarrhea opiates
loperamide and diphenoxyllate
Opiate tolerance that doesn’t go away
No tolerance to miosis or constipation
Butorphanol
Mu-opioid receptor partial agonist and kappa-opioid receptor agonist; produces analgesia. Less resp. depression than full agonists. Can’t reverse with naloxone very easily.
Tramadol
Very weak opioid agonist; also a SNRI, [Tram It All]
Tramadol use
Chronic pain, but decreases seizure threshold and can cause serotonin syndrome.
What drugs can be used for absence seizures
Ethosuximide, valproate, and lamotrigine
What drugs are used in status epilepticus?
Benzos and Phenytoin(PPx)
What are the first line agents for tonic clonic seizures
Phenytoin, Carbamazepine, and Valproate.
What is the first line agents for Simple and complex seizures
Carbamazepine only, Carbamazepine is best for all partial seizures and tonic clonic.
What drugs can’t be used for partial seizures
Ethosuximide (Thalamic channels) and Benzos
Ethosuximide side effects
EFGHIJ: Ethosuximide causes, Fatigue, GI distress, Headache, Itching, and Stevens-Johnson syndrome.
Tx eclampsia seizures
1st line is MgSO4, benzos are second line.
ethosuximide MOA
Thalamic T-type Ca2+ channels
Topiramate non-seizure use
Migraine PPx
1st line for trigeminal neuralgia
Carbamazepine
Carbamazepine MOA
Inc. Na+ channel inactivation
Phenytoin MOA
Inc. Na channel inactiation; zero order kinetics
Valproate MOA
Inc. Na channel inactivation, inc. GABA conc. by inhibiting GABA transaminase
Gabapentin MOA
Blocks high voltage-activated Ca channels, GABA analog
Topiramate MOA
Blocks Na channels, inc. GABA action
Lamotrigine MOA
Blocks voltage-gated Na channels
Levetiracetam MOA
Unknown; may modulate GABA and glutamate release
Tiagabine
Inc. GABA by inhibiting re uptake
Vigabatrin MOA
Inc. GABA by irreversibly inhibiting GABA transaminase
Barbiturates MOA
Prolong GABAa opening duration.
Barbiturates contraindication
Porphyria
Barbiturates overdose tx
Assist respiration and maintain BP
Benzos MOA
Increase GABAa frequency of opening. Decrease REM.
Flumazenil MOA
competitive antagonist at GABA benzo receptor
Nonbenzodiazepine hypnotics
Zolpidem, Zaleplon, esZopiclone “All ZZZs put you to sleep.”
Nonbenzo hypnotics MOA
Act via the BZ1 subtype of the GABA receptor. Effects reversed by flumazenil.
Anesthetic dec. solubility in blood leads to
rapid induction and recovery times
Anesthetic inc. solubility in blood leads to
inc. potency
Potency formula
1/MAC
Inhaled anesthetics Effects
Myocardial depression, resp. depr. N/V, INCREASED Cerebral blood flow (dec. cerebral metabolic demand)
Halothane tox
hepatotoxicity
Methoxyflurane tox
nephrotoxicity
Enflurane tox
proconvulsant
Nitrous oxide tox
Expansion of trapped gas in a body cavity
What drugs cause malignant hyperthermia
All inhaled anesthetics except nitrous oxide and succinyl choline. HEREDITARY CONDITION. Tx is dantrolene.
Thiopental drug class
Barbiturates
Thiopental pharmacokinetics
high potency, high lipid solubility, rapid entry into brain, rapidly redistributed. DECREASES CEREBRAL BLOOD FLOW.
Midazolam use
Most common drug for endoscopy
Midazolam toxicity
Severe postop resp. depressino, dec. BP, anterograde amnesia.
Arylcyclohexylamines
Ketamine, blocks NMDA receptors
Ketamine effects
CV stimulant, disorientation, hallucinations, bad dreams. Inc. cerebral blood flow.
Propofol
Potentiates GABAa
Amide local anesthetics
Have 2 I’s in the name, bupivicaine, lidocaine, mepivacaine.
Local anesthetics MOA
binds Na+, especially when activated, so best in rapidly firing neurons.
Fact: tertiary amine local anesthetics penetrate membrane in uncharged form, then bind to ion channels as charged form.
.
Fact: in infected (acidic) tissue, alkaline anesthetics are charged and cannot penetrate membrane effectively, need more anesthetic.
.
What are the alkaline anesthetics?
Local anesthetics are all weak bases!!! So acidic tissue is bad for all local anesthetics. So sick tissue needs more anesthetic than happy tissue.
Order of nerve blockade for local anesthetics
Small diameter > large diameter. myelinated > unmyelinated
Order of loss with local anesthetics
- Pain
- Temp
- Touch
- Pressure
Which local anesthetic is toxic to the heart
Bupivicaine
Which local anesthetic causes arrhythmias:
Cocaine
Depolarizing neuromuscular blockers toxicity
HyperCa, hyperK, malignant hyperthermia
Nondepolarizing blockers
Tubocurarine, atracurium, mivacurium, pancuronium, vecuronium, rocuronium
Nondepolarizing MOA
Competitive antagonists at NMJs, all are like curare
Nondepolarizing antidote
Neostigmine (msut be given with atropine to pervent muscarinic effects like bradycardia), edrophonium, and other AChEIs.
Phase I of succinylcholine
Prolonged depolarization, no antidote, AChEIs potentiate the effect.
Phase II of succinylcholine
Repolarized but blocked; ACh receptors available but desensitized: antidote of AChEIs
Non-ergot DA agonists
Pramipexole and ropinirole
parkinson drugs
BALSA
Bromocriptine, Amantadine, Levodopa (w/ carbidopa), Selegiline (and COMT inhibitors), Antimuscarinics
Amantadine MOA
May inc. DA release, antiviral for flu A and rubella; toxicity=ataxia
Selegiline MOA
selective MAO type B inhibitor
COMT inhibitors
Entacapone, tolcapone: prevent L-dopa degradation
Benztropine MOA
Antimuscarinic; improves tremor and rigidity but little effect on bradykinesia