MENINGITIS AND ENCEPHALITIS

Question 1

Most common causative organisms of meningitis in those aged 3 months and older?

Answer 1

Neiserria meningitidis
Strep pneumoniae
HIb

Question 2

Most common causative organisms of meningitis in neonates?

Answer 2

Strep agalactiae (GBS)
E.coli
S. Pneumonia
Listeria monocytogenes

Question 3

Immediate management of meningitis?

Answer 3

A_>E assessment
Senior review
critical care review may be necessary

Question 4

What can GPs give to patients with suspected meningitis in the community?

Answer 4

IM benzylpenicillin
(Cefotaxime if allergic to penicillins)

Question 5

MOA of benzylpenicllin?

Answer 5

It’s a beta lactam
Inhibits the biosynthesis of the cell wall peptidoglycan

Question 6

Contraindications to benzylpenicillin?

Answer 6

Hypersensitivity to penicillins

Question 7

Adverse effects of benzylpenicillin?

Answer 7

GI disturbance
Hypersensitivity
Skin reactions
Thrombocytopenia

Less commonly - antibiotic-associated colitis, arthralgia and leukopenia

Question 8

Interactions with benzylpenicillin?

Answer 8

Warfarin
Methotrexate

Question 9

Management of meningitis in hospital?

Answer 9

IV access - blood and cultures
LP if it can be done within an hour
IV antibiotics cefotaxime or ceftriaxone (+amoxicillin if >50)
IV dexamethasone

Question 10

Why are cephalosporins used for meningitis?

Answer 10

Known bactericides activity for associated bacteria
Increased ability to cross the BBB

Question 11

MOA of cefotaxime?

Answer 11

A beta lactam antibiotic
Binds to penicillin-binding proteins via beta-lactam rings and inhibit the cells wall synthesis

Question 12

Contraindications to cefotaxime?

Answer 12

Hypersensitivity to cephalosporins
Immediate hypersensitivity to penicillin

Question 13

Adverse efefcts of cefotaxime?

Answer 13

Abdominal pain, diarrhoea, n&v
Hypersensitivity
Skin reactions
Cholestatic jaundice
Blood disorders
Antibiotic-associated colitis

Question 14

Interactions with cefotaxime?

Answer 14

Ibuprofen - increases risk of nephrotoxicity
Aminoglycosides - increases risk of nephrotoxicity
Methotrexate - increases risk of nephrotoxicity

Question 15

What can be given to help prevent or treat cerebral oedema and act as an adjunct treatment of bacterial meningitis?

Answer 15

Dexamethasone 10mg IV
(Note in meningococcal septicaemia)

Question 16

Contraindications of dexamethasome?

Answer 16

Systemic infections
Live vaccines if high doses

Question 17

Interactions with steroids?

Answer 17

Drugs that cause hypokalaemia e.g. loop diretics, lithium, amiodarone
NSAIDs - bleeding
Nicorandil - perforation
Digoxin - toxicity
Warfarin - increases anticoagulant effect
Clarithromycin - increased exposure to steroids
Ketoconazole - increased exposure to steroids

Question 18

Most common cause of encephalitis?

Answer 18

HSV

Question 19

How would you treat suspected herpes simplex encephalitis?

Answer 19

Aciclovir IV for at least 14 days (21 days if immunocompromised)

Repeat LP to confirm CSF is negative before stopping!

Question 20

MOA of aciclovir?

Answer 20

Competitively inhibits viral DNA polymerase and DNA replication of different herpesvirs

Question 21

Common side effects of aciclovir?

Answer 21

GI disturbance
Skin reactions and photosensitivity
Renal impairment
CNS effects
Hepatic disorders
Blood disorders

Question 22

Interactions with aciclovir?

Answer 22

Aminophylline
NSAIDs
Trimethoprim
Methotrexate
Amingoglycosides
Cephalosporins

Question 23

What must you communicate to the pt when starting aciclovir?

Answer 23

To be very hydrated - to prevent acute kidney crystallopathy/nephrotoxic