Neuro Drugs Flashcards
Epinephrine is an…
alpha-agonist that decreases aqueous humor synthesis via vasoconstriction. (use for open-angle glaucoma)
Side effects of Epinephrine
mydriasis (do NOT use in closed-angle glaucoma)
Brimonidine is an…
alpha2-agonist that decreased aquous humor synthesis (glaucoma)
Brimonidine side effects
-blurry vision -ocular hyperemia -foregin body sensation -ocular allergic rxn and pruritis
Timolol, betaxolol and carteolol are…
beta-blockers that decrease aqueous humor synthesis. (glaucoma)
Acetazolamide is a…
diuretic that decreases aqeous humor synthesis via inhibition of carbonic anhydrase.
Pilocarpine and Carbachol are…
direct cholinomimetics that increase outflow of aqueous humor via contraction of ciliary muscle and opening of trabecular meshwork. (glaucoma)
Side effects of Pilocarpine and Carbachol
miosis and cyclospasm (contraction of ciliary muscle)
Physostigimine and Echothiophate are..
indirect cholinomimetics that can be used in emergencies and are very effective at opening meshwork into the canal of Schlemm.
Latanoprost is a…
PGF2alpha agonist that increases outflow of aqueous humor.
Latanoprost side effect
darkens color of iris
Opioid analgesics (8)
- morphine 2. fentanyl 3. codeine 4. loperamide 5. methadone 6.meperidine 7. dextromethorphan 8. diphenoxylate
Opioids mechanism
act as agonists at opioid receptors to modulate synaptic transmission (open K+ channels and close Ca2+ leading to decreased synaptic transmission); this inhibits release of ACh, NE, 5-HT, glutamate and substance P
opiod receptors
mu = morphine delta = enkephalin kappa = dynorphin
Clinical use of opioids (5)
pain cough suppression diarrhea (loperamide and diphenoxylate) acute pulmonary edema maintenance for heroin addicts (methadone)
Toxciity of opioids
-addiction -respiratory depression -constipation -miosis -additive CNS depression
Butorphanol MOA
mu-opioid partial agonist and kappa-opioid agonist; produces analgesia
Use of Butorphanol
-severe pain
Butorphanol can cause opioid withdrawal symptoms if…
pt is also taking full opioid agonist.
Tramadol MOA
weak opioid agonist; also inhibits serotonin and NE reuptake
Use of Tramadol
chronic pain
Toxicity of Tramadol
-similar to opioids -decreases seizure threshold -serotonin syndrome
Ethosuximide use
absence seizures (first line)
MOA of Ethosuximide
blocks thalamic T-Type Calcium channels
Side effects of Ethosuxamide
EFGHIJ -fatigue -GI distress -Headache -Itching -stevens-Johnson syndrome
Benzodiazepines (2)
- Diazepam 2. Lorazepam
Use of Diazepam and Lorazepam
status epilepticus
MOA of Benzodiazepines
increase GABAa action (can also be used for eclampsia seizures)
SE of Benzodiazepines
sedation, tolerance, dependence, respiratory depression
Phenytoin Use
Simple partial seizures complex partial seizures tonic-clonic seizures status epilepticus
Phenytoin MOA
increase Na+ channel inactivation; zero-order kinetics
Phenytoin side effects
-nystagmus -diplopia -ataxia -sedation -gingival hyperplasia -hirsutism -neuropathy -megaloblastic anemia -teratogenesis -SLE-like syndrome -induces CYP450s -Stevens Johnson -osteopenia
Carbamazepine use
simple and complex partial seizures tonic-clonic seizures (1st line use for trigeminal neuralgia)
Carbamazepine MOA
increased Na+ channel inactivation
Side effects of Carbamazepine
-diplopia -ataxia -blood dyscrasias -liver toxicity -teratogenesis -induces CYP450s -Stevens Johnson -SIADH
Valproic Acid uses
simple and complex partial seizures tonic-clonic seizures absence seizures (also for myoclonic seizures and bipolar disorder)
Valproic Acid MOA
-increased Na+ channel inactivation -increased GABA concentration by inhibiting GABA trasmaminase
Valproic Acid Side Effects
-rare but fatal hepatotoxicity (need to meausre LFTs) -neural tube defects (spina bifida) -tremor -weight gain
Gabapentin uses
-partial and complex partial seizures -tonic-clonic seizures (also for peripheral neuropathy, postherheptic neuralgia, migraine prophylaxis and bipolar disorder)
Gabapentin MOA
primarily inhibits high-voltage-activated Ca2+ channels; designed as GABA analog
Gabapentin SE
-sedation -ataxia
Phenobarbital uses
-simplex and complex partial seizures -tonic-clonic seizures (1st line in neonates)
Phenobarbital mechanism
increased GABAa action
Phenobarbital side effects
-sedation -tolerance -dependence -CYP450 induction -cardiorespiratory depression
Topiramate uses
-simple and complex seizures -tonic-clonic seizures (also for migraine prophylaxis)
Topirimate MOA
blocks Na+ channels and increases GABA action
Topirimate SE
-sedation -mental dulling -kidney stones -weight loss
Lamotrigine uses
-simple and complex partial seizures -tonic clonic seizures -absences seizures
Lamotrigine MOA
-blocks voltage-gated Na+ channels
Lamotrigine SE
Stevens-Johnson
Levetiracetam uses
-simple and complex seizures -tonic-clonic seizures
Levetiracetam MOA
unknown; may modulate GABA and glutamate release
Tiagabine uses
simple and complex partial seizures
Tiagabine MOA
increase GABA by inhibiting re-uptake by GAT-1
Vigabatrin uses
simplex and complex partial seizures
Vigabatrin MOA
Increases GABA by irreversibly inhibiting GABA tramsaminase
Stevens-Johnson syndrome is…
a prodrome of malaise and fever followed by rapid onset of erythematous/purpuric macules. Skin lesions progress to epidermal necrosis and sloughing.
Barbituates (4)
- Phenobarbital 2. Pentobarbital 3. Thiopental 4. Secobarbital
Barbituates MOA
facilitate GABAa action by increasing the duration of Cl- channel opening, thus decreasing neuron firing
Barbiturates are contraindicated in…
porphyria
Use of Barbituates
-sedative for anxiety -seizures -insomnia -induction of anesthesia (thiopental)
Barbituate toxicity
-respiratory and CV depression -CNS depression -dependence -drug interactions
OD of barbituates treatment is…
supportive (assist respiration and maintain BP).
Benzodiazepines (8)
- Dizaepam 2. Lorazepam 3. Triazolam 4. Temazepam 5. Oxazepam 6. Midazolam 7. Chlordiazepoxide 8. Alprazolam
Benzodiazpeines MOA
facilitate GABAa action by increasing frequency of Cl- channel opening; decrease REM
Most BDZs have long half-lives and active metabolites except…
triazolam, oxazepam and midazolam which are short acting and have higher abuse potential.
Use of BDZs
-anxiety -spasticity -status epilepticus -night terrors -detoxification -sleepwalking -general anesthetic -insomnia
Toxicity of BDZs
-dependence -additive CNS depression w/ alcohol (less risk of respiratory depression than barbituates)
Treatment of BDZ overdose
Flumazenil (competitive antagonist at GABA benzodiazepine receptor)
Nonbenzodiazepine Hypnotics (3)
- Zolpidem 2. Zaleplon 3. esZopiclone
MOA of Zolpidem, Zaleplon, and Eszopiclone
act via the BZ1 subtype of GABA receptor
use of zolpidem, zaleplon, and eszopiclone
insomnia
Drugs with decreased solubility in the blood have…
rapid induction and recovery times.
Drugs with increased solubility in lipids have…
increased potency = 1/MAC. (MAC = minimal alveolar concentration required to prevent 50% of subjects from responding to noxious stimuli)
Neuromuscular blocking drugs are used for…
muscle paralysis in surgery/mechanical ventilation. Selective for motor nicotinic receptor.
Succinylcholine is a strong…
ACh receptor agonist that produces sustained depolarization and prevents muscle contraction.
Phase II of the succinylcholine blockade can be reversed by…
cholinesterase inhibitors (these potentiate the block in phase I).
Complications of Succinylcholine include…
hypercalcemia, hyperkalemia and malignant hyperthermia.
Tubocurarine, Atracurium, Mivacurium, Pancuronium, Vecuronium and Rocuronium are…
competitive antagonists for the ACh receptor.
Reversal of nondepolarizing blockade of ACh receptors is with…
neostigmine (give w/ atropine to prevent bradycardia), edrophonium.
Dantrolene MOA
prevents release of Ca2+ from the SR of skeletal muscle
Dantrolene use
malignant hyperthermia and neuroleptic malignant syndrome
Parkinsonism is due to…
loss of dopaminergic neurons and excess cholinergic actiivty.
Dopamine agonists (3)
Bromocriptine Pramipexole Ropinerole (for Parkinsonism)
Parkinson drugs that increase dopamine
Amantadine (also used as an antiviral for influenza A and rubella) L-dopa/carbidopa
Parkinson drugs that prevent the breakdown of dopamine
Selegiline (selective MAO-B inhibitor) Entacapone/Tolcapone (COMT inhibitors)
Parkinson drugs that curb excess cholinergic activity
-Benztropine (antimuscarinic; improves rigidity and tremor but not bradykinesia)
Levodopa Mechanism
increases the level of dopamine in the brain because it can cross the BBB (unlike dopamine) and is then convernted to DA by dopa decarboxylase; used for Parkinson
Carbidopa is a…
peripheral decarboyxlase inhibitor given with L-dopa to increase the availability of L-dopa in the brain and decrease peripheral side effects
Toxicity of L-dopa
arrhythmias from increased peripheral formation of catecholamines; alternating dyskinesia and akinesia
Selegine MOA
selectively inhibits MAO-B which metabolizes dopamine
Alzhemier drugs (4)
Memantine Donepezil, Galantamine, Rivastigmine
Memantine MOA
NMDA receptor antagonist; helps prevent excitotoxicity
Donepezil, galantamine, rivastigmine MOA
AChE inhibitors
Toxicity of Memantine
dizziness, confusion, hallucinations
Toxicity of donepezil, galantamine, rivastigmine
nausea, dizziness, insomnia
Huntington drugs (3)
Tetrabenazine, reserpine Haloperidol
Tetrabenazine and Reserpine
inhibit vesicular monoamine transporter (VMAT); limits dopamine vesicle packaging and release
Haloperidol is a…
dopamine receptor antagonist
Sumatriptan MOA
5-HT1b/1d agonist that inhibits trigeminal nerve activation; prevents vasoactive peptide release; induces vasoconstriction
Toxicity of sumatriptan
coronary vasospasm (contraindicated in pts with CAD or Prinzmetal angina)