Aminoglycosides
Moderate
Database
Synergistic Gram-negative coverage (intended)
Standard combination; monitor renal function
Source: Kimi deep-research + Cla
Drug reference
Aztreonam
Monobactam (β-lactam) antibiotic · Antibacterial
START
1–2 g IV/IM every 8–12 h (severe Gram-negative)
TYPICAL MAX
8 g/day
STOP IF
Severe hypersensitivity, C. difficile colitis, or hepatotoxicity
WATCH
Renal function (dose-banding), LFTs, ceftazidime allergy history
CDSCO approvedATC J01DF01
KDIGO 2024 + manufacturer label
- ONSET
- 6min · infusion start
- PEAK
- 30min · end infusion
- t½
- 1.7h · t½
- DURATION
- 8h · q8h
EXCRETION
Renal — 60–70% unchanged
route + CYP
INTERACTIONS
—
none in our sources
PREGNANCY
Considered acceptable when indicated (β-lactam class).
FDA category + note
Mechanism
Binds penicillin-binding protein 3 of Gram-negative aerobes, inhibiting bacterial cell-wall synthesis; selective for aerobic Gram-negatives (including Pseudomonas) with no Gram-positive or anaerobic activity.
Indications
Complicated urinary tract infectionsLower respiratory tract infections (including cystic fibrosis Pseudomonas, inhaled form)SepticaemiaIntra-abdominal infections (combined with anaerobe coverage)Skin/soft-tissue infections (Gram-negative)Pelvic inflammatory disease
Dosing
- Adult
- 1–2 g IV/IM every 8–12 h (severe: 2 g q6–8h). Inhaled (CF): 75 mg nebulised three times daily for 28-day cycles.
- Pediatric
- ≥9 months: 30 mg/kg every 6–8 h; CF inhaled per protocol.
- Renal adjustment
- CrCl 10–30: reduce dose 50%. <10: reduce 75%; dose after HD.
- Hepatic adjustment
- Caution; reduce dose in severe disease.
- Geriatric
- Adjust for renal function.
- Max dose
- 8 g/day
Pharmacokinetics
Onset
Bactericidal levels from infusion
Peak effect
End of infusion
Duration
Dose every 6–12 h
Half-life
~1.7 h (~6 h in severe renal failure)
Bioavailability
IV/IM 100%; inhaled local
Protein binding
~56%
Metabolism
Minimal
Excretion
Renal (60–70% unchanged)
Contraindications
- Severe hypersensitivity to aztreonam
- Generally tolerated in penicillin allergy (no cross-reactivity except ceftazidime)
- Caution: severe ceftazidime allergy (shared side chain)
Side effects
Common
Injection-site phlebitisRashNausea/vomitingDiarrhoeaTransaminase elevation
Serious
- Severe hypersensitivity (rare)
- C. difficile colitis
- Hepatotoxicity (rare)
- Seizures (high dose, renal failure)
Pregnancy & lactation
Pregnancy
Considered acceptable when indicated (β-lactam class).
Lactation
Compatible with breastfeeding.
Drug interactions
Ceftazidime
Moderate
Database
Shared side chain
Avoid if severe ceftazidime allergy
Source: Kimi deep-research + Cla
Loop Diuretics (e.g., Furosemide)
Moderate
Database
Increased risk of renal dysfunction, particularly when aztreonam is co-administered with other nephrotoxic drugs. Loop diuretics can also reduce aztreonam excretion.
Monitor renal function closely. Be aware of potential for reduced aztreonam excretion, which may necessitate dose adjustment in patients with impaired renal function. Avoid concomitant use with other nephrotoxic agents if possible.
Other Nephrotoxins
Moderate
Database
Renal stress
Monitor renal function
Source: Kimi deep-research + Cla
Probenecid
Moderate
Database
Reduced renal tubular secretion
Monitor; usually no adjustment
Source: Kimi deep-research + Cla
Valproic Acid
Moderate
Database
Decreased serum concentrations of valproic acid, potentially leading to loss of seizure control.
Monitor valproic acid levels closely. Consider increasing valproic acid dose or switching to an alternative antiepileptic drug if clinically indicated. Monitor for seizure recurrence.
6 additional low-confidence interactions hidden — those rows lack a documented mechanism or management plan in our sources.
Related guidelines
Ask House about Aztreonam
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Sources: KD Tripathi 7e, Goodman & Gilman 14e, Harrison 22e, Katzung·Verified: 2026-05-20 · House clinical team·Cockpit curated: 2026-05-20