MENINGITIS AND ENCEPHALITIS Flashcards
Most common causative organisms of meningitis in those aged 3 months and older?
Neiserria meningitidis
Strep pneumoniae
HIb
Most common causative organisms of meningitis in neonates?
Strep agalactiae (GBS)
E.coli
S. Pneumonia
Listeria monocytogenes
Immediate management of meningitis?
A_>E assessment
Senior review
critical care review may be necessary
What can GPs give to patients with suspected meningitis in the community?
IM benzylpenicillin
(Cefotaxime if allergic to penicillins)
MOA of benzylpenicllin?
It’s a beta lactam
Inhibits the biosynthesis of the cell wall peptidoglycan
Contraindications to benzylpenicillin?
Hypersensitivity to penicillins
Adverse effects of benzylpenicillin?
GI disturbance
Hypersensitivity
Skin reactions
Thrombocytopenia
Less commonly - antibiotic-associated colitis, arthralgia and leukopenia
Interactions with benzylpenicillin?
Warfarin
Methotrexate
Management of meningitis in hospital?
IV access - blood and cultures
LP if it can be done within an hour
IV antibiotics cefotaxime or ceftriaxone (+amoxicillin if >50)
IV dexamethasone
Why are cephalosporins used for meningitis?
Known bactericides activity for associated bacteria
Increased ability to cross the BBB
MOA of cefotaxime?
A beta lactam antibiotic
Binds to penicillin-binding proteins via beta-lactam rings and inhibit the cells wall synthesis
Contraindications to cefotaxime?
Hypersensitivity to cephalosporins
Immediate hypersensitivity to penicillin
Adverse efefcts of cefotaxime?
Abdominal pain, diarrhoea, n&v
Hypersensitivity
Skin reactions
Cholestatic jaundice
Blood disorders
Antibiotic-associated colitis
Interactions with cefotaxime?
Ibuprofen - increases risk of nephrotoxicity
Aminoglycosides - increases risk of nephrotoxicity
Methotrexate - increases risk of nephrotoxicity
What can be given to help prevent or treat cerebral oedema and act as an adjunct treatment of bacterial meningitis?
Dexamethasone 10mg IV
(Note in meningococcal septicaemia)
Contraindications of dexamethasome?
Systemic infections
Live vaccines if high doses
Interactions with steroids?
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
Most common cause of encephalitis?
HSV
How would you treat suspected herpes simplex encephalitis?
Aciclovir IV for at least 14 days (21 days if immunocompromised)
Repeat LP to confirm CSF is negative before stopping!
MOA of aciclovir?
Competitively inhibits viral DNA polymerase and DNA replication of different herpesvirs
Common side effects of aciclovir?
GI disturbance
Skin reactions and photosensitivity
Renal impairment
CNS effects
Hepatic disorders
Blood disorders
Interactions with aciclovir?
Aminophylline
NSAIDs
Trimethoprim
Methotrexate
Amingoglycosides
Cephalosporins
What must you communicate to the pt when starting aciclovir?
To be very hydrated - to prevent acute kidney crystallopathy/nephrotoxic
