Phenoxymethylpenicillin (Penicillin V)¶
Overview¶
| Field | Detail |
|---|---|
| Drug class | Natural penicillin / Phenoxypenicillin |
| Route | Oral |
| Forms | 250 mg, 500 mg tablets; 150 mg/5 mL, 250 mg/5 mL suspension |
| Storage | Room temp before; refrigerate suspension after mixing |
Preparation for Oral Challenge¶
Before you start
Ensure the patient has fasted if required. Use a calibrated oral syringe for all volumes. Check the concentration of the suspension (150 mg/5 mL or 250 mg/5 mL).
Reagents¶
- Phenoxymethylpenicillin Suspension (e.g., Cilicaine VK)
- Syringes: 1 mL, 3 mL, 5 mL, 10 mL oral syringes
- Measuring cup
Step-by-step Challenge Protocol¶
Option A: Using 150 mg/5 mL (30 mg/mL) Suspension:¶
| Step | Dose | Volume | Cumulative Dose |
|---|---|---|---|
| 1 | 30 mg | 1.0 mL | 30 mg |
| 2 | 60 mg | 2.0 mL | 90 mg |
| 3 | 120 mg | 4.0 mL | 210 mg |
| 4 | 300 mg | 10.0 mL | 510 mg |
Option B: Using 250 mg/5 mL (50 mg/mL) Suspension:¶
| Step | Dose | Volume | Cumulative Dose |
|---|---|---|---|
| 1 | 30 mg | 0.6 mL | 30 mg |
| 2 | 60 mg | 1.2 mL | 90 mg |
| 3 | 120 mg | 2.4 mL | 210 mg |
| 4 | 300 mg | 6.0 mL | 510 mg |
Challenge Protocol¶
Intervals: Observe for 30–60 minutes between each step. Final Observation: Monitor for 1–2 hours after the final dose.
Notes¶
- Phenoxymethylpenicillin is not routinely used for skin testing. If required, test with Benzylpenicillin, PPL and MD.
- Commonly used for treating mild-to-moderate infections including tonsillitis and pharyngitis.