Block 1 Flashcards
What does a neurologic exam show?
Symmetrical vs asymmetrical function; may identify local lesions within NS
Imaging Tools
PET
SPECT
MRI
CT
CT; images of brain in slices in 1-10mm thickness
MRI; more detailed image vs CT, uses magnet of H+ and protons
PET; excellent resolution, rates of biological process w/ C14-deoxyglucose
SPECT; poorer resolution than PET, radiotracer where tissue uptake gives image
Delirium DSM5
Environmental + Medications
Occurs most in older individuals at ICU, nursing homes, or hospice
Can be caused by substance intoxication
Epidemiology of migraines?
17.1% women and 5.6% men in US have ≥1migraine/yr
After age 12, females are 2-3x more likely to suffer
Highest prevalence in both women and men are aged 30-49
Migraine pathophysiology?
Activity of trigeminovascular system
Vasodilation and activation of perivascular trigeminal nerve which releases vasoactive peptides
Activates hypothalamus and brainstem
Releases CGRP + PACAP
What are the genetic mechanisms behind migraine triggers?
Calcium and sodium channels and PP abnormalities that regulate cortical excitability via SEROTONIN release
Increased levels of excitatory AA such as glutamate
IHS diagnostic classification of Migraine w/o Aura?
≥5 attacks
Lasts 4-72hrs
Lots of sx such as pulsing quality, N/V, photophobia, etc
IHS diagnostic classification of Migraine w/ Aura?
≥2 attacks
Fulfills criteria for atypical pain or aura
What is an aura?
Affects 25% of migraineurs
Lasts for 1 hr
Has both “positive” and negative visual effects
Sensory and motor symptoms occur as well
Epidemiology of tension headache?
1yr prevalence is 31-86%
Peaks in 4th decade and decreases incidence w/ age
Women>Men
Functional impairment occurs in 60% of tension type headache sufferers
Pathophysiology of tension headache?
May originate from myofascial factors, peripheral sensitization of nociceptors, and heightened sensitivity of pain pathways in CNS
Stimuli such as mental stress, etc
How does tension headache present?
Bilateral pain in a hatband pattern
No aura
Minor disabilities vs other headaches
Physical activity doesnt affect severity
Epidemiology of cluster headaches?
Lifetime prevalence is 0.12%
Male:Female ratio is 3:1
Men typically get it in 3rd decade, women at younger age
Predisposition in certain families
65% of pt w/ this headache are current/former tobacco users however cessation doesnt improve the headache :(
Pathophysiology of cluster headaches?
Modulator = hypothalamus
Secondary activation of trigeminal autonomic reflexes
Alterations in circadian rhythm
Clinical presentation of cluster headaches?
Daily attacks for 2wks to several months followed by long pain-free intervals
Occurs commonly at night and in spring/fall
Lasts 15 to 180min
Migraines are typically (bilateral/unilateral)
Unilateral
What are the CGRP receptor antagonists used for migraine prophylaxis?
Erenumab
Fremanezumab
Galcanezumab
What is MIG-99?
Used prophylactically for migraines that is extracted of feverfew daisies
What are the 1st and 2nd Gen serotonin 5-HT1 agonists? Major differences?
Sumatriptan is the only one that is first gen
Everything else is second (rizatriptan, etc)
2nd gen = higher oral bioavailability
What functional group is vital for 5-HT1 agonists?
Indole group
2 benzene rings with one having an N-H
What specific receptors do 5-HT1 agonists target and their MOA?
5-HT1B + D
Vasoconstriction of intracranial arteries
Inhibits vasoactive peptides released from perivascular trigeminal neurons
Inhibits transmission thru 2nd order neurons ascending to thalamus
Which sumatriptan formulation has significant 1st pass effect? When severe GI symptoms present?
1st pass = oral tablet
GI issues = suppositories
Triptans vs ergot alkaloids, which have better anti-migraine efficacies?
Triptans
Which triptans have the longest half life?
Naratriptan and Frovatriptan
5-HT1 agonist AE?
Paresthesia, dizziness, neck pain
Coronary vasospasms
CI in pt w/ CAD and angina, hemiplegic or basilar migraine
What class of drugs are ergotamine and dihydroergotamine (DHE) similar to?
5-HT1 agonists
Caffeine can be added to ergotamine to do what?
Improve rate and extent of oral absorption
Ergotamine and DHE AE and CI?
N/V
CI in renal/hepatic failure, CAD, uncontrolled HTN, pregnancy or nursing mothers
Which receptors do ergotamine and DHE target?
5-HT, alpha, and dopamine 2,3,4
CGRP receptor antagonist general info?
Erenumab is the only human antibody, the other two are humanized
PREVENTS migraines
Metabolized by non-sepcific proteolysis (not by CYP)
Acupuncture and episodic migraine?
They reported less AE vs those w/ Rx and were less likely to drop out
General algorithm for headaches?
If mild/moderate symptoms, use NSAIDs,APAP. If that doesnt work, use fiorcet. If that doesnt work then use Triptans, ergotamine/DHE, CGRPs
If severe symptoms, go straight to Triptans, ergotamine/DHE, CGRPs
Non-pharm Headache Tx?
Ice on head
Rest in a dark, quiet area
What dose and response rate is used as reference for triptans?
Sumatriptan 100 mg dose and 2 hour response rate
What should you NOT take w/ triptans?
MAOIs within 2 wks
Lasmiditan (Reyvow®) info
Serotonin 5-HT1F r agonist
Dose: Once daily
Possible serotonin syndrome, Inhibits OCT1 w/ no interaction to sumatriptan
Primary endpoint: no pain for 2 hrs (20-40%)
Ubrogepant (Ubrevly®) info
First PO CGRP antagonist for acute Tx. PRN
Taken twice a day, max 200mg/24hrs
Second dose is taken 2hrs after the first dose
Metabolized by CYP3A4, avoid with -azoles
Rimegepant (Nurtec ODT®) info
Acute Tx. with/without aura and currently NOT approved for prevention
CGRP antagonist given PO or SL
Mostly metabolized by CYP3A4, avoid with -azoles within 48hrs
Pt consideration when using NSAIDs for acute headaches?
Use suppositories for those with N/V
Don’t overuse NSAIDs cause it will medication-overuse headaches
NSAIDs alone vs Combo products (fioricet)
Which one has a higher chance of medication-overuse headaches?
Combo
Safety tips when using ergotamine?
Dont use within 24hrs of triptans
Prophylactic regimen therapy for headaches?
Recurrence is predictable? (pregnancy, migraine)
*Use triptan or CGRPs
Healthy or heart issues?
*Beta blockers or verapamil if they are contraindicated not effective
Depression or insomnia?
TCAs
Seizure or bipolar?
Anticonvulsants
None of the above work? Combo products/seek specialist
***go down this list, if anticonvulsants dont work, you may use beta blocker or verapamil then go to last step
NSAID therapy info?
Naproxen has the strongest evidence
Use 1-2 days prior to headache and continue using it
Monitor for GI and renal toxicity when using longterm
BB therapy info?
Timolol, propranolol, metoprolol
Might raise migraine threshold
BB w/ intrinsic sympathomimetic activity are ineffective
Triptan therapy info?
Frovatriptan has established efficacy over naratriptan and zolmitriptan (those only have probable efficacy)
Useful in preventing MENSTRUAL migraine, Use 1-2 days prior to headache and continue using it
Antidepressant therapy info?
Amitriptyline, venlafaxine
Downregulates 5-HT2 receptors, increases lvls of norepi, enhanced opioid receptor actions
Limited use due to anticholinergic effects
Caution in BPH and glaucoma and those taking triptans due to serotonin syndrome
Anticonvulsant therapy info?
Valproate, divalproex, topiramate
Inhibits GABA, modulates excitatory glutamate, inhibits sodium and calcium channels
Must titrate to avoid AE
Valproate is CI in pregnancy, pancreatitis, and liver disease
CGRP and Eptinuzmab (Vyepti™) info?
Galcanuzumab (Emgality™) used for migraine and cluster HA
Preventive drugs
Eptinuzmab is given IV q3months. No interactions w/ sumatriptan
What are used in tension HA?
Simple analgesics and NSAIDs
Limit use of NSAIDs for 15 days
Combo 9 days
Butalbital 3 days
Abortive therapy for cluster headaches?
Verapamil is first line; takes about a week
Oxygen 100% 12L/hr for 15-30min; caution in those w/ COPD or smoke
SQ or intranasal triptan; 6mg SQ sumatriptan is more effective, but intranasal is better tolerated
IV dihydroergotamine, sublingual or rectal ergotamine can be used as well
Lithium and corticosteroids can be used
Pathophysiology of seizures?
Inhibits GABA-A
GABA-B are activated, decreases calcium influx and inhibits neurotransmitter release
Glutamate is the excitatory NT that produces seizures
What are the highest RF for SUDEP?
Generalized seizures
Seizures >3/year
Which antiepileptic Rx display non-linear PK?
Phenytoin and ethotoin
Valproate when doses >2.5g/day, ethosuximide when doses >1.5g, gaba and pregabalin, and carbamazepine
Antiepileptic therapy + special population?
Women = increased drug clearance, secretion of rx in breast milk, fetal malformations
Men = possibility of reduced fertility
Peds = altered PK and need to adjust dose
Geriatric = decrease your dose and many rx interactions
Important Rx interaction with valproate?
Lamotrigine
Phenobarbital (increased conc of it)
Which antiepileptic drugs dont have any interactions and why?
Gabapentin, pregabalin, Vigabatrin, and Keppra due to renal excretion
General AED AE?
Idiosyncratic rxns, blood dyscrasias, SJS/rash, aplastic anemia, pancreatic issues
Carbamazepine AE?
Hyponatremia, leukopenia (d/c if WBC<2500), decreased bone density
Ethosuximide AE?
N/V, titrate the dose slowly
Cenobamate info?
Used for partial onset seizures in adults
DRESS AE
Clobazam info?
BZD derivative
Abrupt d/c may cause withdrawal symtpoms
Controlled
Eslicarbazepine info?
Pro drug, also better oral absorption vs carbamazepine
Up to 1200mg/day
Hyponatremia
Ezogabine AE?
Urinary retention (careful w/ anyone that has BPH or on anticholinergics) and QT prolongation, blue skin discoloration and retina pigment change
Felbamate info?
AE = weight loss and anorexia
Limited use and only for those who dont respond to other agents
Gabapentin/Pregabalin info?
L-amino acid GI absorption
Pregabalin is a controlled agent and more potent
Lamotrigine info?
Pt w/ hx of rash are more likely to have a rash with this Rx
Warning of HLH
Oxcarbazepine info?
Prodrug, better oral absorption vs carbamazepine
Can cause hyponatremia
Perampanel info?
AMPA receptor antagonist
Causes dizziness and somnolence
Phenobarbital info?
Causes delayed development in kids and cognitive impairment in adults, and toxic epidermal necrolysis
Parental product contains propylene glycol and alcohol
Phenytoin info?
Do NOT give IM
Uses Michaelis-Menten kinetics
100 mg phenytoin = 92mg phenytoin sodium
Causes gingival hyperplasia and skin issues, ataxia nystagmus
Topiramate AE
Can cause kidney stones and metabolic acidosis. Cleft palate in newborns too
Valproic acid info?
UGT and beta oxidation
Causes hyperammonemia and platelet issues
Vigabatrin info?
S enantiomer is active
Can cause seizures
Zonisamide info?
Related to sulfonamide
Can cause decreased sweat, weight loss, and kidney stones
What is Dravet Syndrome?
Epilepsy at 1-18 months, variant of SCN1A
Can present in kids or adults
How do you treat Dravet Syndrome?
1st line: Valproic acid or Clobazam
2nd line: stiripentol (w/ valproic acid or clobazam) or topiramate or ketogenic diet
3rd line: AED addition or vagus nerve stimulator
Lipophilicity and onset of action/duration?
More lipophilic = more rapid onset = shorter duration = high logP
What does primidone form?
Phenobarbital + PEMA
PEMA is the weaker anticonvulsant, but is the major metabolite. Is has more toxicity issues
Phenobarbital and primidone induce what?
CYP2C
CYP3A
UGT