Ampicillin

證據等級: L5

預測適應症: 10 個

Ampicillin: From Bacterial Infections to Laryngitis

One-Sentence Summary

Ampicillin is a broad-spectrum aminopenicillin antibiotic with a long-established history of treating a wide range of bacterial infections, including respiratory, urinary tract, gastrointestinal, and skin infections. The TxGNN model predicts it may be effective for Laryngitis, with 1 clinical trial and 20 publications currently supporting this direction. The available evidence is largely indirect — largely drawn from related ENT infections and broad penicillin-class literature — and key safety data was not retrieved in this Evidence Pack, warranting a Hold decision pending data completion.

Quick Overview

Item	Content
Original Indication	Broad-spectrum bacterial infections (respiratory, urinary tract, meningitis, skin infections)
Predicted New Indication	Laryngitis
TxGNN Prediction Score	99.97%
Evidence Level	L3
Canada Market Status	Not Marketed (per current dataset)
Number of DINs	0
Recommended Decision	Hold

Why Is This Prediction Reasonable?

Detailed mechanism of action data was not retrieved from DrugBank in this Evidence Pack. Based on established pharmacological knowledge, Ampicillin is an aminopenicillin (broad-spectrum beta-lactam) that inhibits bacterial cell wall synthesis by irreversibly binding to penicillin-binding proteins (PBPs). This disrupts peptidoglycan cross-linking, leading to osmotic instability and bacterial cell death. Its spectrum covers key Gram-positive organisms (including Streptococcus pyogenes, Streptococcus pneumoniae) and select Gram-negative organisms (including Haemophilus influenzae) — all recognised pathogens in upper respiratory tract infections.

Laryngitis — inflammation of the larynx — is predominantly viral, but bacterial laryngitis does occur, most commonly caused by S. pneumoniae, H. influenzae, and Moraxella catarrhalis. Ampicillin’s in vitro and clinical activity against these organisms provides a mechanistic basis for the TxGNN model’s prediction. The drug has historically been included in empirical treatment regimens for acute upper respiratory infections, including pharyngitis, tonsillitis, and epiglottitis, which share overlapping pathogen profiles with bacterial laryngitis.

That said, the evidence retrieved in this pack is almost entirely indirect: the single registered clinical trial examined amoxicillin/clavulanate (not ampicillin alone) across a mixed paediatric respiratory cohort that included laryngitis as one of several indications, and the literature largely consists of case reports, case series, and observational studies describing laryngeal infections where beta-lactams were employed. No dedicated RCT evaluating ampicillin specifically for laryngitis was identified.

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT01406275	N/A	Completed	363	Post-marketing surveillance of CLAVAMOX® (amoxicillin/clavulanate) in Japanese paediatric patients; covered multiple indications including laryngitis, pharyngitis, tonsillitis, skin infections, and urinary tract infections — not specific to ampicillin alone or to laryngitis as a primary endpoint

Literature Evidence

PMID	Year	Type	Journal	Key Findings
39879424	2025	Guideline Review	CoDAS	AGREE II quality assessment of clinical guidelines for laryngitis and pharyngitis management; highlights current evidence base and gaps
35923122	2023	Case Report + Review	Ann Otol Rhinol Laryngol	Historical and modern review of spontaneous laryngeal abscess; antibiotics (including beta-lactams) remain the cornerstone treatment; modern cases associated with immunosuppression and diabetes
34986973	2023	Case Report	Auris Nasus Larynx	COVID-19 presenting as acute epiglottitis with necrotic laryngeal lesions; illustrates the need for antibiotic cover in severe laryngeal infections
38145982	2024	Observational	Eur Arch Otorhinolaryngol	Microbiological analysis and antibiotic selection in neck abscesses among diabetic patients; supports broad-spectrum penicillin-class antibiotics in deep ENT infections
30579693	2019	Case Report	Auris Nasus Larynx	Post-transplant laryngeal actinomycosis in a 14-year-old; treated with prolonged penicillin course — demonstrates beta-lactam efficacy in laryngeal infections
24930374	2014	Case Report	J Voice	Laryngeal actinomycosis in a 74-year-old immunocompromised patient; penicillin (beta-lactam class) resolved infection after laryngeal biopsy-guided diagnosis
12402494	2002	Case Series	Acta Otorrinolaringol Esp	Two cases of paraglottic laryngeal abscess — a rare, life-threatening condition requiring urgent diagnosis and antibiotic therapy
7487676	1995	Animal Study	Auris Nasus Larynx	Ampicillin ± ibuprofen in experimental acute otitis media (chinchilla model); demonstrates ampicillin’s antibacterial efficacy in upper respiratory tract bacterial infections
41536375	2025	Case Report	Cureus	Croup differential diagnosis in a 3-year-old; case highlights when bacterial aetiology should be reconsidered and antibiotic therapy escalated
1712371	1991	Case Series	J Clin Gastroenterol	Short-term antibiotic treatment in Whipple’s disease; one patient treated with ampicillin 2 g/day with clinical response — documents ampicillin’s clinical use

Canada Market Information

No approved products (DINs) for Ampicillin were found in the Health Canada regulatory dataset included in this Evidence Pack.

Note: The absence of DINs in this dataset may reflect a data retrieval gap rather than a true absence from the Canadian market. Ampicillin and its prodrug forms (e.g., pivampicillin, bacampicillin) have been widely used internationally. A direct search of the Health Canada Drug Product Database (DPD) is recommended to confirm current market status.

Safety Considerations

Key warnings, contraindications, and drug interaction data were not retrieved in this Evidence Pack. Before proceeding with any clinical evaluation:

Please refer to the ampicillin product monograph and Health Canada package insert for complete safety information. Clinically important considerations include: hypersensitivity reactions and cross-reactivity in penicillin-allergic patients (including risk of anaphylaxis), antibiotic-associated diarrhoea and Clostridioides difficile infection, ampicillin-associated maculopapular rash in patients with infectious mononucleosis (EBV), and interactions with oral anticoagulants and probenecid.

Conclusion and Next Steps

Decision: Hold

Rationale: This Evidence Pack is missing critical safety data (warnings, contraindications, drug interactions), and the Canada regulatory data shows no DINs currently on record — both represent blocking gaps that prevent a complete first-stage safety screening. While ampicillin’s mechanistic rationale for bacterial laryngitis is sound and its broad antimicrobial use is well established, the evidence in this pack is entirely indirect with no dedicated trial specifically evaluating ampicillin for laryngitis, and no comparative efficacy data in this indication.

To proceed, the following is needed:

Retrieve the Health Canada product monograph / package insert for ampicillin to complete safety pre-screening (warnings, contraindications, DDI)
Confirm Canadian market availability via direct Health Canada DPD query
Determine whether any dedicated clinical trials for aminopenicillins (ampicillin or amoxicillin) in bacterial laryngitis have been conducted or are ongoing
Clarify target clinical context: bacterial vs. viral laryngitis, acute vs. chronic, severity spectrum, and intended patient population (paediatric vs. adult)
Review current Canadian antibiotic resistance surveillance data for common laryngitis pathogens (particularly Streptococcus pyogenes and H. influenzae) to confirm that ampicillin retains adequate in vitro activity in the Canadian context
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.