Meningitis

Question 1

What are the layers of the meninges?

Answer 1

Dura mater (outer), arachnoid mater (middle), pia mater (inner).

Question 2

Where does infection occur in meningitis?

Answer 2

Subarachnoid space (contains cerebrospinal fluid).

Question 3

What are the two CNS barriers affecting drug penetration?

Answer 3

Blood-brain barrier (BBB) and blood-CSF barrier (BCSFB).

Question 4

Which drug properties enhance CNS penetration?

Answer 4

Low molecular weight, lipophilicity, low protein binding, unionized state.

Question 5

How does meningeal inflammation affect CSF drug penetration?

Answer 5

It increases penetration of many antibiotics.

Question 6

Name antibiotics that achieve therapeutic CSF levels even without inflammation.

Answer 6

Acyclovir, TMP/SMX, Voriconazole, Fluconazole, Linezolid, Metronidazole.

Question 7

Name antibiotics that only penetrate CSF during inflammation.

Answer 7

Penicillins, ceftriaxone, vancomycin, meropenem.

Question 8

Name antibiotics that do NOT achieve therapeutic CSF levels.

Answer 8

Macrolides, aminoglycosides, clindamycin, 1st/2nd gen cephalosporins.

Question 9

What are typical CSF findings in bacterial meningitis?

Answer 9

WBC > 1000, neutrophils > 80%, protein > 150, glucose < 50.

Question 10

What are CSF findings in fungal meningitis?

Answer 10

WBC 10–500, lymphocyte predominance, protein 40–150, low glucose.

Question 11

What are CSF findings in viral meningitis?

Answer 11

WBC 5–300, lymphocyte predominance, mild protein elevation, normal glucose.

Question 12

What are the common pathogens in neonates (<1 month)?

Answer 12

Group B Strep, Listeria, E. coli.

Question 13

What is empiric therapy for neonates with meningitis?

Answer 13

Ampicillin + cefotaxime or gentamicin.

Question 14

What are the common pathogens in adults 2–50 years?

Answer 14

Strep pneumoniae, N. meningitidis.

Question 15

What is empiric therapy for adults 2–50 with meningitis?

Answer 15

Vancomycin + ceftriaxone.

Question 16

What is empiric therapy for adults >50 or immunocompromised?

Answer 16

Vancomycin + ceftriaxone + ampicillin.

Question 17

What is the role of dexamethasone in meningitis?

Answer 17

Reduces mortality and neurologic sequelae in pneumococcal meningitis.

Question 18

When should dexamethasone be administered?

Answer 18

Before or with the first dose of antibiotics.

Question 19

What is used to treat S. pneumoniae meningitis?

Answer 19

Penicillin or ceftriaxone ± vancomycin depending on resistance.

Question 20

How is Neisseria meningitidis treated?

Answer 20

Penicillin G or ceftriaxone for 7 days.

Question 21

What is the treatment for Listeria monocytogenes?

Answer 21

Ampicillin ± gentamicin for 21 days.

Question 22

What is used for MSSA meningitis?

Answer 22

Nafcillin.

Question 23

What is used for MRSA meningitis?

Answer 23

Vancomycin.

Question 24

How long is treatment for Gram-negative bacilli meningitis?

Answer 24

21 days.

Question 25

What is the induction regimen for cryptococcal meningitis?

Answer 25

Liposomal amphotericin B + flucytosine for 2 weeks.

Question 26

What is the consolidation therapy for cryptococcal meningitis?

Answer 26

Fluconazole 400–800 mg daily x 8 weeks.

Question 27

What is maintenance therapy for cryptococcal meningitis?

Answer 27

Fluconazole 200 mg daily x 6–12 months.

Question 28

When should ART be initiated in HIV patients with cryptococcal meningitis?

Answer 28

After 5 weeks of antifungal therapy.

Question 29

What is the treatment for HSV encephalitis in adults?

Answer 29

Acyclovir 10 mg/kg IV q8h x 14–21 days.

Question 30

What is the treatment for VZV encephalitis?

Answer 30

Acyclovir 10–15 mg/kg IV q8h x 10–14 days.

Question 31

Which viruses are commonly reactivated in encephalitis?

Answer 31

HSV-1, HSV-2, VZV, CMV, HHV-6.

Question 32

What is the typical dose of ceftriaxone for meningitis?

Answer 32

2 g IV q12h.

Question 33

What is ceftriaxone used for in meningitis?

Answer 33

Empiric and directed therapy for S. pneumoniae and N. meningitidis.

Question 34

What is the class and MOA of ceftriaxone?

Answer 34

Third-generation cephalosporin; inhibits bacterial cell wall synthesis.

Question 35

What is vancomycin's role in meningitis?

Answer 35

Covers penicillin-resistant S. pneumoniae; used empirically with ceftriaxone.

Question 36

What is the MOA of vancomycin?

Answer 36

Inhibits cell wall synthesis by binding D-Ala-D-Ala.

Question 37

Does vancomycin penetrate CSF?

Answer 37

Only during meningeal inflammation.

Question 38

What is the dose of ampicillin in Listeria meningitis?

Answer 38

2 g IV q4h.

Question 39

What is the MOA of ampicillin?

Answer 39

Beta-lactam; inhibits bacterial cell wall synthesis.

Question 40

What is ampicillin used for in meningitis?

Answer 40

Empiric and directed therapy for Listeria, especially in neonates and elderly.

Question 41

What is gentamicin's role in meningitis?

Answer 41

Synergistic with ampicillin for Listeria or enterococcal meningitis.

Question 42

What is the MOA of gentamicin?

Answer 42

Inhibits protein synthesis by binding 30S ribosomal subunit.

Question 43

Does gentamicin penetrate the CSF?

Answer 43

Poorly, even with inflammation.

Question 44

What is the dose of acyclovir for HSV encephalitis?

Answer 44

10 mg/kg IV q8h for 14–21 days (based on IBW).

Question 45

What is the MOA of acyclovir?

Answer 45

Inhibits viral DNA polymerase after activation by viral thymidine kinase.

Question 46

What are key adverse effects of acyclovir?

Answer 46

Nephrotoxicity (crystalluria), neurotoxicity.

Question 47

What is the key monitoring with acyclovir?

Answer 47

Renal function and adequate hydration.

Question 48

What is fluconazole used for in meningitis?

Answer 48

Consolidation and maintenance therapy for cryptococcal meningitis.

Question 49

What is the MOA of fluconazole?

Answer 49

Inhibits fungal CYP450 14α-demethylase.

Question 50

Does fluconazole penetrate CSF?

Answer 50

Yes, achieves high CSF levels even without inflammation.

Question 51

What is the dose of flucytosine in cryptococcal meningitis?

Answer 51

100 mg/kg/day divided q6h.

Question 52

What is the MOA of flucytosine?

Answer 52

Converted to 5-FU → inhibits fungal DNA/RNA synthesis.

Question 53

What is a major adverse effect of flucytosine?

Answer 53

Bone marrow suppression.

Question 54

Why is flucytosine not used as monotherapy?

Answer 54

Rapid development of resistance.

Question 55

What is the typical dose of liposomal amphotericin B in meningitis?

Answer 55

3–5 mg/kg IV daily.

Question 56

What is the MOA of amphotericin B?

Answer 56

Binds ergosterol, forms membrane pores.

Question 57

What is amphotericin B used for in meningitis?

Answer 57

Induction therapy for cryptococcal meningitis.

Question 58

What are key toxicities of amphotericin B?

Answer 58

Nephrotoxicity, electrolyte abnormalities, infusion reactions.

Question 59

What is the dose of dexamethasone in bacterial meningitis?

Answer 59

0.15 mg/kg IV q6h x 2–4 days.

Question 60

What is dexamethasone used for in meningitis?

Answer 60

Adjunctive therapy to reduce inflammation in pneumococcal meningitis.

Question 61

When should dexamethasone be started?

Answer 61

Before or with the first dose of antibiotics.