Bugs + Drugs

Question 1

which species of bacteria grow hyphae

Answer 1

nocardia and actinomyces

these are both gram positive rods, so to differentiate,
nocardia is aerobic, actinomyces is anaerobic

mn: they are gram pos. because they have the “addition” of hyphae.

Question 2

Answer 2

cryptococcus

commonest cause of fungal meningitis

Risk factors:AIDS; Exposure to pigeon droppings

Diagnostics: Cryptococcal antigen testing via latex agglutination; CSF gram staining: India Ink (clear halo)

Question 3

characterize West Nile Virus

Answer 3

enveloped +ssRNA

Question 4

characterize HSV encephalitis

Answer 4

enveloped, dsDNA, spherical

associated with temporal lobe hemorhagic necrosis

bimodal age distribution, with peak distribution at
early childhood and 50+, ages

Question 5

what are the vaccine preventable causes of brain infections?

Answer 5

N. meningiditis and Japanese B virus

Question 6

Answer 6

Coccidioides immitis

Question 7

which CBS infectious pathogen enters via the trogan horse method (i.e intracellularly via phagocytosis)

Answer 7

listeria monocytogenes

Question 8

best way to detect viral meningitis

Answer 8

Many tests can help to differentiate viral from bacterial meningitis; however, a viral polymerase chain reaction is the most accurate test. This test detects viral genetic material.

Question 9

Answer 9

Neisseria meningitidis

Question 10

characterize neisseria meningitidis

Answer 10

gram neg aerobic diplococci

glucose and maltose fermenting

osidase +

non-hemolytic

likes CO2

mn: Neisseria is Neg.

Question 11

what is the most common cause of septic meningitis with a hypotensive patient

Answer 11

N. meningitidis (also look for petuchial rash)

Question 12

abx for: Listeria, N. meningitidis, Strep, E. coli (sensitive)

Answer 12

ampicillin

Question 13

empiric abx for non-infant meningitis

Answer 13

vancomycin, ceftriaxone, Cefepime (or cefotaxime)

+ampicillin if 50+ yo or immunocompromised

Question 14

what drug would cover all of these:

Pseudomonas, N. meningitidis, E. coli, H. influenzae, Strep, Staph (sensitive)

Answer 14

cefepime

Question 15

What is the most common means for drug entry
into the CNS?

Answer 15

transcellular diffusion (Small, lipophilic molecules)

Question 16

CYP expression in the brain is High or low?

Answer 16

LOW, meaning that it does not appreciably affect drug metabolism

instead, Instead, drugs get “pumped
out” by ATP Binding Cassette
ABC Transporters such as P-gp, MRP1, MRP2, MRP3, and BCRP

Question 17

Amphetamine MOA

Answer 17

• Displaces monoamines from vesicles
• Reverses direction of monoamine reuptake transporters
• Inhibits metabolism of monoamines by the enzyme, MAO-A

result= increased Monoamine in synaptic cleft

Question 18

tranexamic acid MOA and indication

Answer 18

synthetic derivative of the amino acid lysine and binds the 5 lysine binding sites on plasminogen. This inhibits plasmin formation and is therefore antifibrinolytic. Indicated for intracranial hemorrhage

Question 19

Tolcapone MOA and indication

Answer 19

inhibits conversion of L-DOPA into its metabolite 3-OMD –> increases conversion to dopamine instead

Question 20

Rasagiline MOA and indication

Answer 20

inhibits MAOb which converts Dopamine –> DOPAL

increases CNS levels of dopamine for PD

Question 21

how do Gabapentin, L-DOPA, and Vinca alkaloids cross the BBB

Answer 21

Protein Carriers GLUT, MCT1,

L-DOPA, –> LAT1

Question 22

Heroin MOA

Answer 22

Presynaptic: inhibits voltage gated calcum channels (decrease neurotransmitter release)
Postsynaptic: opens K+ channels (K efflux –> hyperpolarization)

Question 23

Cocaine MOA

Answer 23

1. Blocks voltage-gated Na+ channels
2. Inhibits monoamine reuptake

Question 24

what would CSF studies reveal in TB meningitis

Answer 24

very low glucose levels

high proteins

lymphocyte predominance

(basically, it shares features of both bacterial and viral infection)

Question 25

what are the notable AE of Keppra (levetiracetam)

Answer 25

irritability, depression, psychosis (rare)

Question 26

adverse AE of Phenytoin

Question 27

AE of valproate

Answer 27

hepatotoxicity, weight gain, PCOS, pancreatitis, alopecia, hyperammonemia, tremor

Question 28

AE of topiramate

Answer 28

renal stones, glaucoma, weight loss, metabolic acidosis, anomic aphasia, brain fog.

Question 29

notable AE of lamotrigine

Answer 29

Stevens johnson syndrome

Question 30

other than for focal seizures, what other seizure type is phenytoin indicated for

Answer 30

status epilepticus (after attempting benzos)

Question 31

what is the first line agent for status epilepticus

Answer 31

benzodiazepines (diazepam, lorazepam, midazolam) (all except Clobazam)

Question 32

what types of SZ is Vigabatrin contraindicated for

Answer 32

absence and myoclonic most common indication ins west syndrome (infantile spasms)

Question 33

what is the first line drug for migraine prevention

Answer 33

topiramate

Question 34

which seizure med can cause psychiatric sx

Answer 34

levetiracetam

Question 35

which SZ drugs can cause hyponatremia

Answer 35

carbamazepine, oxcarbazepine, eslicarbazepine

Question 36

which SZ drug can cause aplastic anemia (highest risk)

Answer 36

felbamate | (deficiencey in all blood cell types)

Question 37

which drugs decrease OCP efficacy?

Answer 37

the carbs and phens carbs: Carbamazepine, Oxcarbazepine, Eslicarbazepine, phens: Phenytoin, Phenobarbital mn: Phanny likes to take her OCPs with carbs

Question 38

What 3 drugs are effective for absence seizures?

Answer 38

Ethosuximide, Valproic acid, Lamotrigine

Question 39

which SZ drugs are a/w intrauterine growth restriction if taken during pregnancy

Answer 39

Phenytoin and carbamazepine

Question 40

which SZ drugs are a/w neural tube defects

Answer 40

valproate

Question 41

which sz drugs are indicated for LGS (lennox)

Answer 41

valproate ,lamotrigine, Clobazam (adjunct)

Question 42

The major toxicity of valproic acid is

Answer 42

hepatotoxicity, for which LFTs must be monitored regularly

Question 43

what major AE is assoc with lamotrigine

Answer 43

SJS

Question 44

what is the risk factor specific to Asian populations when taking Carbamazepine

Answer 44

The HLA-B\*1502 haplotype most often seen in patients of Asian descent is associated with an increased risk of the development of Stevens-Johnson syndrome or Toxic Epidermal Necrolysis triggered by carbamazepine therapy.

Question 45

what is tabes dorsalis

Answer 45

Tabes dorsalis is caused by tertiary syphilis and arises due to degeneration and demyelination of the dorsal columns and roots. Clinically, it manifests with progressively worsening ataxia, lancinating pains, absent deep tendon reflexes , and light-near dissociation (occurs when the pupillary light reaction is impaired while the near reaction (accommodative response) remains intact.) (ie. Argyll-Robertson ## Footnote pupil)

Question 46

what features of CSF suggest viral over bacterial brain infection?

Answer 46

The correct answer is normal glucose, elevated protein, and lymphocytosis (D). Normal glucose is an important distinction because in bacteria-induced encephalitis, there is decreased glucose.

Question 47

Which of these pathogens does Vancomycin cover? Streptococcus pneumoniae; Haemophilus influenzae; Neisseria meningitidis

Answer 47

Streptococcus pneumoniae. Vancomycin has really good activity against Gram Pos cocci, and a few Gram Pos rods (e.g., Campylobacter, but NOT Listeria or Nocardia)

Question 48

selegiline MOA

Answer 48

MAOb inhibitor

Question 49

Bromocriptine MOA

Answer 49

→ ergot dopamine agonist

Question 50

tx for essential tremor

Answer 50

propranolol

Question 51

what enzyme converts L-DOPA to dopamine in CNS

Answer 51

Dopa decarboxylase