Anti Epileptics
Phenytoin Side Effects
ataxia, nystagmus, hirsutism, gingival hyperplasia, coarsening of facial features
Drugs That Increase dopamine function
levodopa, tolcapone, entacapone, selegiline, rasagiline
Triptan MOA
5HT 1B and 5HT 1D serotonin receptor agonism (selective), vasoconstriction (1B), modulate neurotransmitter release, inhibit trigeminal nerve activation
local anesthetic MOA
Injection sites from highest to lowest vascularity
Intercostal > caudal (sacral hiatus) > brachial plexus > sciatic nerve
5 cardinal effects of general anesthesia
unconsciousness, analgesia, amnesia, skeletal muscle relaxation, loss of autonomic reflexes
body fluid compartments and % body water
intracellular - 40%, extracellular - 20%
Drug of Choice for Absence Seizures
Ethosuximide
drug that inhibits DOPA decarboxylase, preventing LDOPA -> Dopamine conversion in tissues
Carbidopa
triptan ADE
bitter taste, flushing, paresthesia, ANGINA, vasospasm
amide metabolism
liver amidase
Adjunct to prevent systemic effects
inject epinepherine - causes vasoconstriction, less distribution of anesthetic, less side effects, prolongs local anesthesia
what single drug can achieve all 5 cardinal effects?
None! Requires combination of drugs, inhaled and intravenous (balanced anesthesia)
Subdivisions of extracellular fluid and % body water
interstitial - 15%, plasma - 5%
Valproate Side Effects
elevated liver enzymes, tremor, thrombocytopenia, pancreatitis, alopecia, weight gain, neural tube defects
Toxic Effects of Levodopa
arrhythmia, dyskinesia, "on-off" effects, psychosis, hypotension, vomiting
triptan contraindications
CAD, CVD, uncontrolled HTN
amide t1/2
1.5 - 2 hours, longer with liver disease
extra effect of epinepherine in spinal injection
direct analgesia via postsynaptic alpha 2 receptors in spinal cord
dissociative general anesthetic
ketamine
fluid loss routes and typical volume
urine - 800-1500mL, stool - 250mL, insensible - 600-900
SV2A Binding Seizure Meds
Levetiracetam, brivaracetam
Tolcapone and Entacapone MOA
COMT inhibitors, COMT breaks down L-dopa
acute cluster headache mgmt
100% O2, subQ sumatriptan, nasal/oral zolmitriptan, lidocaine, subQ octreotide (somatostatin), dihydroergotamine (nasal/parenteral)
Amide drugs
lidocaine, bupivacaine, Mepivacain, Etidocaine, Prilocaine
another alpha 2 agonist used as adjuvant anesthetic in spinal anestesia
clonidine
ketamine CNS effects
increased cerebral blood flow; distorted visual, tactile, and auditory sensitivity; hallucinations, vivid dreams, out of body feeling (K - ketamine, "K"ick start my heart!)
required fluid intake for afebrile 70kg man
35mL/kg ~ 2.5 liters
granulocyte suppression, aplastic anemia, SIADH, diplopia, ataxia, spina bifida
dopamine receptor agonists
bromocriptine, pergolide, pramipexole, ropinirole
cluster headache prophylaxis
verapamil, lithium, topiramate, galacanezumab, melatonin, prednisone
why not bupivicaine?
cardiac toxicity
where is epinephrine injection contraindicated?
end arteries (fingers, toes, nose, ear)
ketamine autonomic effects
increased heart rate, blood pressure, and cardiac output; bronchodilation
required fluid intake for body weight <70kg
1st 10kg - 100mL/kg, 2nd 10kg - 50mL/kg, for weight above 20kg - 20mL/kg
Anti Seizure Med Known For Stevens Johnson Syndrome
Lamotrigine
drugs that increase dopamine release
amantadine
Ergot alkaloids
Bupivicaine alternatives
levobupivicaine - less affinity for cardiac sodium channels
ropivacaine - less cardiac affinity, but less effective
signs and symptoms of local anesthetic CNS toxicity
oral/tongue numbness, metallic taste, nystagmus, muscle twitching, seizures, depression, loss of consciousness
cardiac output(CO) and solubility affect on anesthesia activity
high solubility = less anesthesia (anesthesia active when its undissolved), high CO = less anesthesia (fast blood flow ~ less time for gas absoprtion)
Examples of Colloids
albumin, blood products, plasma protein fraction
Anti Seizure Drug Known For General Anesthetic Effects, Used In Status Epilepticus
Phenobarbitol
MAO-B inhibitors
selegiline, rasagiline
dihydroergotamine
ester drugs
cocaine, procaine, tetracaine, benzocaine
benzos(diazepam, lorazepam, treat and prevent), oxygen, propofol, succinylcholine
Minimum Alveolar Concentration of Anesthetic: Drug A - 10, Drug B - 20, which drug is more potent?
Drug A (less drug needed for anesthesia effect)
indications for colloids
intravascular fluid deficit, hypoalbuminemia, protein loss, combine with crystalloids when large volume replacement needed
Felbamate Side Effects
hepatitis, aplastic anemia
on-off phenomenon
unpredictable, sudden shifts of medication working and not working, occurs with levodopa
synthetic ergot derivatives
bromocriptine, pergolide, LSD, methysergide
ester metabolism
butyrylcholinesterase (pseudocholinesterase) in tissue and blood
precautions with pre-medicating to prevent CNS side effects
benzos don't prevent cardiac toxicity, benzos and propofol may delay recognition of cardiac effects
reduced vagal/parasympathetic tone [per AI : )], bronchodilation, reduced uterine and intestinal contractions
examples of crystalloids
normal saline, dextrose in water, lactated ringer solution
Anti Seizure Medication That Follows Zero Order Kinetics
Phenytoin
Drugs that decrease acetylcholine action
benztropine, trihexyphenidyl, diphenhydramine, biperiden, orphenadrine, procyclidine
Ergot MOA
bind 5HT-1B and 5HT-1D serotonin receptors
ester t1/2
< 1 minute
dangerous local anesthetic in pregnancy and why
bupivacaine - no paracervical block due to possible uterine artery constriction, no epidural in pregnancy due to engorged epidural veins in pregnant women, potential for cardiac effects if penetrated [per AI : ) ]
Halothane ADEs
liver failure, arrhythmia (reduced vagal tone), hypotension, malignant hyperthermia
indications for crystalloids
hemorrhagic shock, septic shock, burns
Anti Seizure Med That Causes Autoinduction of its Own Metabolism
Carbamazepine
cholinergic hypothesis
deficiency of acetylcholine is critical in the genesis of Alzheimer's
Ergot peripheral ADEs
leg weakness, muscle pain, numbness/tingling of the fingers
This allows local anesthetics to cross the cell membrane
lipophilic aromatic portion
local anesthetic that causes hypertension
cocaine - prevents reuptake of norepinephrine, dopamine, serotonin
uncontrolled muscle contraction due to excessive calcium outflow
malignant hyperthermia
isotonic fluids
normal saline (0.9%), PlasmaLyte, stereofundin
sole indication for felbamate
refractory seizures that respond poorly to other meds
what drug is the basis for the cholinergic hypothesis and why?
atropine - acetylcholine antagonist, it can induce a confusional state similar to that seen in Alzheimer's
other Ergot ADEs
angina like symptoms, excessive vasoconstriction (non selective serotonin agonist), fibrosis
Basic. They are unionized in a base. Here they stay lipophilic and able to cross the cell membrane.
toxic extracellular sodium channel blockers
tetrodotoxin - puffer fish, saxitoxin - algae
meds that trigger uncontrolled calcium release
volatile anesthetics (halothane, isoflurane, sevoflurane, methoxyflurane, ether), also succinylcholine
hypotonic fluids and complications
lactated ringer (LR), D5W, cellular swelling, tissue edema, increased intracranial pressure
other drugs for absence seizures besides ethosuximide
clonazepam, valproic acid
acetylcholinesterase inhibitors only
Donepezil (Aricept), Galantamine (Razadyne)
Ergot contraindications
pregnancy, PVD, CAD, HTN, impaired renal or hepatic function, don't take w/i 24 hours of triptans
Sodium Bicarbonate (NaHCO3)
types of local anesthesia
surface, infiltration (subcutaneous), conduction block (nerve trunk), spinal (subarachnoid space or L2-3/L3-4), epidural
treatment for uncontrolled calcium release and MOA
Dantrolene - blocks ryanodine receptors on sarcoplasmic reticulum, stopping Ca2+ outflow
hypertonic fluids and complications
1.4%NaHCO3, hypertonic saline, cellular shrinking, hypernatremia
drug for atonic seizures
clonazepam
dual acetylcholinesterase and butyrylcholinesterase inhibitors
Rivastigmine (Exelon), Tacrine (Cognex)
tension headache prophylaxis
amitriptyline
when do local anesthetics block sodium channels
in the inactivated state
advantages of spinal anesthesia
safety, no loss of consciousness
ADEs of volatile anesthetics
desflurane - airway irritation, sevflurane - nephrotoxic, isoflurane - respiratory depression, enflurane - seizures
MAXI drip chamber drop(gtt) volume
10 drops(gtt)/mL
features of fetal hydantoin syndrome
caused by phenytoin, upturned nose, mild midfacial hypoplasia, long upper lip with thin vermillion border
common ADEs of Alzheimer's drugs
GI distress, muscle cramping, abnormal dreams
Triptan metabolism
MAO-A enzyme, triptan's contraindicated in patients taking MAO inhibitors (within 2 weeks)
why does Na channel blockade prevent a nerve impulse?
stops cell membrane depolarization, thus stops action potential
disadvantages of spinal anesthesia
hypotension, nausea, vomitting, headache, neuro damage, septic meningitis
ADEs of fentanyl
respiratory depression, chest wall stiffness
MICRO drip chamber drip (gtt) volume
60 drops (gtt)/mL
corticotropin, prednisone, Vigabatrin is 3rd line
Huntington's Disease medications
fluoxetine, haloperidol, clozapine, quetapine, carbamazepine; w/ seizures - clonazepam, valproic acid; large chorea - tetrabenazine
MORE Triptan contraindications
recent exposure to ergot alkaloids, taking 5-HT receptor agonists
what happens to local anesthetics injected into highly vascular tissue?
high systemic concentration, adverse side effects
prilocaine and benzocaine side effect and how to treat
depolarizing skeletal muscle relaxant
succinylcholine
Tonicity of D5W solution
isotonic at first, cells consume glucose in the fluid and it becomes hypotonic, can cause cerebral edema