Amoxicillin interacts with a defined set of drug classes, and is contraindicated in penicillin allergy and infectious mononucleosis. Screening for these before the first dose prevents almost all serious events.
Interaction classes to screen
| Class | Concern | Action |
|---|---|---|
| Metabolic inhibitors | Raised plasma levels and exaggerated effect | Reduce dose or space administration |
| Metabolic inducers | Reduced exposure and treatment failure | Review response and adjust |
| Same-target agents | Additive pharmacology | Avoid duplicate therapy |
| Agents affecting the same organ system | diarrhoea, rash, candidiasis | Monitor and document |
Key takeaways
- Screen every new prescription against the patient's full medicine list.
- Common reactions, diarrhoea, rash, candidiasis, are amplified by interacting drugs.
- Document the interaction check in the dispensing record.
- Re-screen whenever another long-term medicine is added.
Monitoring in practice
Most interaction risk is manageable with a scheduled review after the onset window of symptom improvement in 48–72 hours and one further check at steady state. Patients on multiple chronic medicines benefit from an annual structured medication review.
Amoxicillin at a glance
| Attribute | Detail |
|---|---|
| Drug class | aminopenicillin antibiotic |
| Common brand | Amoxil |
| Licensed use | respiratory, ENT, dental and urinary infections |
| Available strengths | 250 mg, 500 mg, 875 mg, suspensions |
| Dosage form | capsule / tablet / suspension |
| Typical onset | symptom improvement in 48–72 hours |
| Duration / dosing interval | 8–12 hour dosing interval |
| Storage | below 25 °C; reconstituted suspension refrigerated |
