Neuro Drugs Flashcards
Opioid Mechanism
Open K+ channels, close Ca2+ channels (presynaptically)> decreased synaptic transmission
Opioid Clinical Use
Pain,cough suppression, diarrhea, pulmonary edema, maintenance program for addicts
Opioid Drugs
Morphine, fentanyl, codeine (cough), dextromethorphan (cough), loperamide (diarrhea), diphenoxylate (diarrhea), methadone (addiction help), meperidine
Opioid Toxicity
Addiction, respiratory depression, constipation, miosis, additive CNS depression with other drugs
ANTIDOTE: Naloxone or Naltrexone
Butorphanol
Mu/kappa-opiod receptor partial agonist
Produces Analgesia
Used for : Migraines, Labor, Severe Pain
Can cause withdrawal symptoms
Tramadol
Weak opioid agonist, inhibits Serotonin and NE reuptake
Used for Chronic Pain
Toxicity: Similar to opioids, increased risk of seizures, can cause Serotonin Syndrome
Benzodiazepines Mechanism
Binds to GABA Cl- receptor complex > increased frequency of Cl channel opening > hyperpolarization > decreased excitation
Facilitates GABA action
Benzodiazepines Use
1st line for Status Epilepticus Anesthesia Induction Anxiety Eclampsia Detox (alcohol withdrawal) Hypnotic (insomnia)
Benzodiazepines Drugs
Diazepam (Status Epilepticus, Detox) Lorazepam(Status Epilepticus) Triazolam, temazepam, oxazepam Midazolam (Anesthesia), Chlordiazepoxide (Detox) Alprazolam
Benzodiazepines Toxicity
Decreased REM sleep, CNS depression (less than barbituates), Dependence
ANTIDOTE: Flumazenil
Barbiturates Mechanism
Allosterically modulate GABA receptors > increased duration of Cl channel opening > increased efficacy of GABA
Barbiturates Use
Partial and Tonic-Clonic seizures, Anesthesia Induction, Anxiety, Insomnia
Barbiturates Drugs
Phenobarbital (Seizures)
Pentobarbital
Thiopental (Anesthesia)
Secobarbital
Barbiturates Toxicity
Respiratory and Cardio depression, CNS depression, dependence
Induces P-450
NonBenzodiazepine hypnotics
Zolpidem (Ambien), Zaleplon, esZopiclone (ZZZ’s)
Used for Insomnia, short duration
Mechanism: increases Cl conductance of GABA receptor (BZ1 subtype)
Antidote: Flumazenil
Can cause: ataxia, headaches, confusion.
Ethosuximide
Used for Absence seizures
Mechanism: Blocks Thalamic T-type Ca channels
Side effects: Fatigue, GI distress, Headache, Itching, Stevens-Johnson syndrome
Phenytoin
Used for partial, tonic-clonic (1st line), and status epilepticus (prophylaxis)
Mechanism: Na Channel inactivation > inhibition of Glutamate release and enhanced GABA release
Side effects: Teratogenic, Megaloblastic Anemia, Drug induced Lupus (SLE), Neuropathy, Gingival hyperplasia, hirsutism (bearded lady), Stevens-Johnson syndrome
P-450 inducer
Carbamazepine
1st line medication for partial and tonic-clonic seizures, as well as trigeminal neuralgia
Mechanism: Na Channel inactivation
Side effects: Teratogenic, Hepatoxicity, Stevens-Johnson syndrome, blood dyscrasias (agranulocytosis, aplastic anemia), SIADH, P-450 inducer
Valproic Acid
1st line medication for tonic-clonic seizures, also used for partial and absence seizures, bipolar disorder
Mechanism: Na Channel inactivation, and inhibits GABA transaminase> increases GABA concentration
Side effects: GI distress, hepatotoxicty, neural tube defects (spina bifida), tremor, weight gain
Lamotrigine
Used for all seizures but not in status epilepticus
Mechanism: Blocks voltage-gated Na channels
Side effects: Stevens-Johnson syndrome
Gabapentin
Used for partial and tonic-clonic seizures
Also used for peripheral neuropathy, postherpetic neuralgia, migraine prophylaxis, and bipolar disorder
Mechanism: Inhibits voltage-gated Ca channels, designed as GABA analog but doesn’t work this way
Side effects: Sedation, ataxia
Topiramate
Used for partial and tonic-clonic seizures
Migraine prophylaxis
Mechanism: Inhibits voltage-gated Na channels, potentiates GABA action
Side effects: Kidney stones, weight loss, sedation
Tiagabine
Used for partial seizures
Mechanism: Inhibits GABA reuptake
Vigabatrin
Used for partial seizures
Mechanism: Inhibits GABA transaminase
Levetiracetam
Used for partial and tonic-clonic seizures
Unknown mechanism
Sumatriptan
Used for acute migraine, cluster headaches
Mechanism: 5-HT agonist, inhibits trigeminal nerve activation, induces vasoconstriction
Side effects: Coronary vasospasm, tingling
Contraindicated in patients with Prinzmetal’s Angina and CAD
Inhaled anesthetics
Halothane (hepatotoxcity) Enflurane (proconvulsant) Isoflurane Sevoflurane Methoxyflurane (nephrotoxcity) Nitrous Oxide (expansion of trapped gas)
Causes myocardial/respiratory depression, nausea/emesis, increases cerebral blood flow and decreases cerebral metabolic demand
Can all (except NO) cause malignant hyperthermia > treat with Dantroline
Intravenous anesthetics
Barbiturates (thiopental), benzodiazepines (midazolam), Ketamine (NMDA receptor blocker), Opioids (morphine, fentanyl), and Propofol (potentiates GABA)
Michael Jackson died from home use of Propofol (now you can’t forget it)
Local anesthetics
Esters (procaine, cocaine, tetracaine)
Amides (lidocaine, mepivacaine, bupivacaine) 2 I’s
Mechanism: block Na channel, preferentially activated channels
Used for minor procedures and spinal anesthesia(epidurals). Given with vasoconstrictors (epinephrine) to enhance local action. Infected tissue requires higher dose.
If allergic to esters, give amides
Order of loss: pain, temperature, touch, pressure
Order of nerve blockade: small myelinated fibers > small unmyelinated fibers > large myelinated fibers > large unmyelinated fibers
Succinycholine
Depolarizing neuromuscular block
Used for muscle paralysis in surgery and intubation, very short acting
Mechanism: ACh receptor agonist > sustained depolarization > repolarized but blocked
Side Effects: hypercalcemia, hyperkalemia, malignant hyperthermia
ANTIDOTE: Neostigmine and other AChE inhibitors
Nondepolarizing neuromuscular blocks
Tubocurarine, atracurium, mivacurium, pancuronium, vecuronium, rocuronium
Competitive ACh antagonists
ANTIDOTE: Neostigmine and other AChE inhibitors
Dantrolene
Treats malignant hyperthermia and neuroleptic malignant syndrome
Ryanodine inhibitor
Parkinson drugs
BALSA
Bromocriptine (dopamine agonist)
Amantadine (increase dopamine release)
Levodopa (increase dopamine. Used with carbidopa)
Selegiline (MAO- inhibitor, prevents dopamine breakdown)
Antimuscarinics (Benztropine)
Can use COMT inhibitors (entacapone, tolcapone)
Alzheimer drugs
Memantine (NMDA receptor antagonist, helps prevent excitotoxicity) can cause confusion and hallucinations
Donepezil, rivastigmine, galantamine (AChE inhibitors)
Huntington drugs
Haloperidol (dopamine receptor antagonist)
Tetrabenazine/reserpine (inhibit VMAT -> limit dopamine vesicle packaging and release)
Epilepsy drugs that cause Stevens-Johnson syndrome
Lamotrigine, phenytoin, carbamazepine, ethosuximide, phenobarbital
