Acute bacterial meningitis
Bacteria reach the subarachnoid space and set off purulent inflammation of the meninges. The picture unfolds over hours: fever, headache, neck stiffness, photophobia, confusion; in infants, refusal to feed, a bulging fontanelle and seizures. Lumbar puncture makes the diagnosis, and the intravenous antibiotic goes in within the first hour, before culture results. Hours matter: delay changes the outcome.
ICD-10 G002 drugs
Also known as: Purulent meningitis
Drugs used for this condition
- AMeropenemSecond line · Carbapenem antibiotic for intravenous useAcute bacterial meningitis stands among the indications in the AEMPS Archifar label, with its own higher dose: inflamed meninges let meropenem into the cerebrospinal fluid, but the concentration has to be kept high. Empirical first-line therapy in Europe usually differs – ceftriaxone with vancomycin, plus ampicillin where listeriosis is a risk. Meropenem comes in when a cephalosporin does not fit: severe allergy to it, hospital-acquired meningitis after neurosurgery, or cultured flora resistant to cephalosporins. Carbapenems carry a rare adverse effect that matters here: the label lists seizures among uncommon reactions, and in a patient with meningitis they are easy to read as the illness itself. Valproic acid in this combination is followed by drug levels.
- CChloramphenicolThird line · Amphenicol antibiotic for systemic useThe FDA label names meningeal infections caused by Haemophilus influenzae and gram-negative meningitis among the indications for systemic chloramphenicol. The reason is historical and pharmacological: the drug enters cerebrospinal fluid without meningeal inflammation, and before third-generation cephalosporins it filled that niche. Today first-line therapy is different, and chloramphenicol stays as a fallback for severe beta-lactam allergy or where ceftriaxone is unavailable. The constraint is hard: the same label carries a boxed warning about fatal blood dyscrasias, so a full blood count goes every two days through the course, and the course itself stays as short as the illness allows. In the first weeks of life the drug is given only with blood level monitoring, because it accumulates.
How to read tiers A–F
Evidence tiers belong to the drug-indication pair, not to the drug as a whole: the same substance can be A for one condition and F for another.
- AStrong evidence – first or second line in international guidelines
- BRecommended in selected cases
- CStudy data contradict each other
- DBenefit not proven, no documented harm
- FDocumented harm, or risk without benefit