Ampicillin

Evidence Level: L4

Predicted Indications: 10

Ampicillin
Ampicillin: From Bacterial Infections to Laryngitis

## Pharmacist Assessment Report

Ampicillin: From Bacterial Infections to Laryngitis

One-Sentence Summary

Ampicillin is a beta-lactam antibiotic originally used for urinary tract infection, otitis media, bacterial pneumonia, meningitis and other bacterial infections. The TxGNN model predicts it may be effective for laryngitis (score 99.97%), but no clinical trials are registered and the 20 publications retrieved are mostly about epiglottitis, laryngeal abscess and neck infections rather than laryngitis itself, so evidence is weak.

Quick Overview

Item	Content
Original Indication	Urinary tract infection, infectious otitis media, bacterial pneumonia, bacterial meningitis and other bacterial infections (the Singapore licence records contain no indication text, so this comes from the knowledge-graph indication list)
Predicted New Indication	Laryngitis
TxGNN Prediction Score	99.97%
Evidence Level	L4
Singapore Market Status	✓ Marketed
Number of Registrations	4
Recommended Decision	Hold

Why is This Prediction Reasonable?

Detailed mechanism-of-action data is not available in the data compiled for this report. Ampicillin is known to be a beta-lactam antibiotic that inhibits bacterial cell wall synthesis, and its efficacy in many bacterial respiratory and ear infections is established.

Bacterial infections of the larynx and supraglottis, such as epiglottitis caused by Haemophilus influenzae and deep neck abscess, are plausibly susceptible to this mechanism. That is the basis of the prediction.

There is an important caveat. Uncomplicated laryngitis is usually viral, and antibiotics do not help viral infections. The retrieved literature concerns bacterial supraglottic and neck infections, not laryngitis. The high TxGNN score is therefore not backed by direct clinical evidence for this indication.

Clinical Trial Evidence

Currently no related clinical trials registered.

Literature Evidence

The 20 retrieved publications are mostly case series, reviews and case reports. Those most relevant to ampicillin are listed below.

PMID	Year	Type	Journal	Key Findings
3977063	1985	Review	Anaesth Intensive Care	161 children with acute epiglottitis; airway management by intubation is the priority, with five deaths
3026014	1986	Review	Rev Infect Dis	Sulbactam/ampicillin for acute epiglottitis in children, as beta-lactamase-producing H. influenzae type b became more common
3322611	1987	Case series	Clin Otolaryngol	19 adult epiglottitis cases; bacteriology and therapeutic principles
6881564	1983	Case series	Anesth Analg	23 children with epiglottitis treated with ampicillin or chloramphenicol; duration of intubation reviewed
3290661	1988	Case series	Monatsschr Kinderheilkd	Ampicillin-resistant H. influenzae type b changed the treatment of epiglottitis
2603419	1989	Review	West J Med	9 adults with epiglottitis; intubation needed in 4
35923122	2023	Case report/Review	Ann Otol Rhinol Laryngol	Historical review and a modern case of spontaneous laryngeal abscess
25944348	2015	Cohort	Otolaryngol Head Neck Surg	Perioperative antibiotic choice and complications after laryngectomy
38145982	2024	Cohort	Eur Arch Otorhinolaryngol	Microbiology and antibiotic selection in neck abscesses in diabetic patients
39879424	2025	Guideline appraisal	CoDAS	Quality assessment of clinical guidelines for laryngitis and pharyngitis (AGREE II)

No randomized trial of ampicillin in laryngitis was found.

Singapore Market Information

Authorization Number	Product Name	Dosage Form	Approved Indication
SIN00680P	STANDACILLIN FOR INJECTION 0.5 g/vial	Powder for solution for injection	Not recorded
SIN01949P	UNASYN 3000 FOR INJECTION	Powder for solution for injection	Not recorded
SIN01948P	UNASYN 1500 FOR INJECTION	Powder for solution for injection	Not recorded
SIN01950P	UNASYN 750 FOR INJECTION	Powder for solution for injection	Not recorded

All four licences are valid single-ingredient registrations, and all are injectable.

Safety Considerations

Contraindications and warnings from knowledge-graph associations (not label text): Kidney disease and impaired renal function, hematologic disease, peptic ulcer disease, Clostridium difficile colitis, perinatal necrotizing enterocolitis, infectious mononucleosis, chronic Epstein-Barr virus infection syndrome, acute urate nephropathy and pyoureter.
Drug Interactions: 61 interactions were identified. The main ones are:
- Moderate: doxycycline, minocycline, tetracycline, kanamycin, balsalazide, lansoprazole, dexlansoprazole, picosulfuric acid.
- Minor: clarithromycin.
- Level not graded: pantoprazole, omeprazole, ranitidine, vancomycin, morphine, prednisone, prednisolone, hydrocortisone, potassium chloride, nystatin, lactulose.

For label warnings and contraindications, please refer to the package insert.

Conclusion and Next Steps

Decision: Hold

Rationale: Ampicillin has a plausible antibacterial link to bacterial supraglottic infections, but there are no registered trials, and the literature covers epiglottitis and neck abscess rather than laryngitis, which is usually viral. Ampicillin is also used less in epiglottitis now because of beta-lactamase-producing H. influenzae. The TxGNN score alone does not justify progressing.

To proceed, the following is needed:

Clear separation of bacterial supraglottic infections (e.g., epiglottitis) from viral laryngitis, to define whether a bacterial laryngitis subgroup exists
Current local susceptibility data for H. influenzae and other relevant pathogens in Singapore
Comparison against current first-line therapy, including ampicillin-sulbactam
Package insert warnings and contraindications from the HSA
Mechanism-of-action data from DrugBank
Approved indication text for the Singapore licences
Disclaimer

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