At a glance
- Coverage is about likely bacterial activity, not symptom matching.
- Resistance can mean a medicine no longer works against a bacterium.
- A laboratory result may help, but requires clinical interpretation.
- A conceptual chart is not a prescribing tool.
Coverage is not a promise
A medicine may have activity against a bacterial group in general, while a particular strain is resistant. It also needs to reach the infection site in an effective way. Clinicians interpret the whole picture, sometimes with laboratory tests.
Online “coverage charts” omit many important considerations and can easily be misapplied to a real illness.
A conceptual coverage chart
| Concept | What it tells you | What it cannot tell you |
|---|---|---|
| Spectrum | The general range of bacteria a drug may act against | Whether a particular infection will respond |
| Susceptibility testing | How a sampled bacterium responds in a laboratory | What treatment is safe for an individual by itself |
| Clinical assessment | Combines symptoms, tests and medical history | Cannot be replaced by a generic online table |
This chart intentionally names no drug-to-bacterium combinations. It cannot guide self-treatment.
What broad and narrow add to the picture
Broad spectrum refers to activity across a wider range of bacteria, while narrow spectrum is more focused. Neither tells you which infection you have, whether you need an antibiotic or which medicine you should take.
The useful patient question
If you have been prescribed an antibiotic, it is reasonable to ask the clinician what they are treating and when you should seek further advice. Do not use a coverage table to change or share a prescription.
Sources
Original referencesThese sources informed this overview. Their organisations do not endorse or review this website.
This page is for general education only. It does not replace advice from a doctor, pharmacist or other qualified healthcare professional. Read our medical disclaimer.