Clinical beta
FMBM is currently in clinical beta. Content is for professional review/testing and must not replace local protocols, senior clinical judgment, or official prescribing references.
Drug Monograph
Metronidazole
Nitroimidazole (PO, IV)
Indication
Intra-abd anaerobes β’ C. diff β’ trichomonas β’ giardia β’ H. pylori β’ necrotizing fasciitis combo
INDICATIONS (CORE USE)
Anaerobes + protozoa + **C. diff oral/IV** (IV for fulminant sometimes) β **disulfiram-like reaction** with alcohol; **peripheral neuropathy** prolonged.
ADULT DOSE (STANDARD)
500 mg IV/PO q8h many anaerobic infections; C. diff per guideline dosing
MAX DOSE
4 g/day IV rare short burst β toxicity watch
Route
PO, IV, topical
PEDIATRIC DOSE
35β50 mg/kg/day divided q8h (max per peds reference)
Must-not-miss safety points
Major warning
- **Alcohol / propylene glycol** β disulfiram reaction - **Peripheral neuropathy** with prolonged courses - **Encephalopathy** high-dose prolonged - Metallic taste common
USE IF: Anaerobic bacterial infection, C. diff, protozoa. AVOID IF: Concurrent disulfiram; alcohol use disorder without counseling; trivial infections.
Primary
Secondary
Other
STANDARD (ADULT PO)
500 mg IV/PO q8h (anaerobic) OR 500 mg PO TID (CDI per guideline)
ADULT DOSE
500 mg q8h IV/PO anaerobic; C. diff 500 mg PO TID/IDSA
PEDIATRIC DOSE
Weight-based.
MAX DOSE
High-dose protocols short β watch neuro toxicity.
Practical Note
IV and PO similar mg for many indications.
Clinical warnings
Adverse effects
Pediatrics
35β50 mg/kg/day divided q8h (max per peds reference)
Pregnancy
Avoid first trimester if possible
Lactation
compatible generally short courses.
Renal impairment
Adjust in severe renal failure per label for some toxic metabolites β consult. **CrCl scaffold (FMBM β titrate to FDA/SFDA label + institutional pharmacy nomogram):** - **CrCl β₯50** β standard dosing - **CrCl 10β50** β monitor for accumulation symptoms; adjust per label if needed - **CrCl <10** β metabolites accumulate β **reduce dose/interval** per label; **HD** removes partially β redose timing
Hepatic impairment
Severe hepatic impairment β reduce dose / avoid prolonged.
Elderly
Neuropathy risk; drug interactions.
IV infusion; PO with food if GI upset; **no alcohol** during + 48h after.
Clinical Picture
**Life-threatening (first):** **seizures**, **coma**, **encephalopathy** (high dose/prolonged). **Secondary:** peripheral neuropathy; disulfiram-like reaction with alcohol.
Immediate Actions
Stop drug β seizure care if needed; supportive
Antidote
No specific antidote; treat complications (encephalopathy/seizures β supportive Β± specialist protocols; anaphylaxis rare β epinephrine per ACLS)
Decontamination
Charcoal if early large ingestion
Escalation
Status epilepticus, coma, severe neuropathy β **ICU** / neurology; **severe accumulation in renal failure β consider hemodialysis** (removes drug partially) β nephrology consult
Common mistakes, resistance logic, and bedside traps
**Anaerobe + C. diff + STI protozoa** workhorse. **Alcohol = vomit storm**. **Warfarin** interaction massive.
Stewardship: donβt add metro βfor anaerobesβ to every cellulitis. C. diff: oral route unless ileus/fulminant. IV metro does not treat colonic CDI as well as oral. *Stewardship (all antimicrobials):* Empiric choice β syndrome severity + **local antibiogram**; shortest effective course.
Hepatic metabolism; good CNS penetration; penetrates abscess.
Intracellular reduction β toxic radicals β DNA strand breaks in anaerobes/parasites.
Global data (no country-specific data available)
Saudi Arabia
(placeholder β verify local formulary)
Common trade names are curated examples only β formulations and availability vary. Verify the exact product name with your local pharmacy and national regulator before prescribing or dispensing.
Saudi Arabia
International