Penicillin V Oral Dose and Uses
Phenoxymethylpenicillin guidance for streptococcal pharyngitis, scarlet fever, and diphtheria completion therapy.
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Source reviewed
January 2024
Guide category
Oral drugs
Safety boundary
Prescription medicine information for clinician-guided use.
Kenza Health Hub presents this medicine page as structured health education. Check dose, route, interactions, pregnancy or breast-feeding considerations, and local protocol with a qualified clinician or pharmacist. Read our medical editorial policy.
Quick clinical summary
| Item | Summary |
|---|---|
| Drug | Phenoxymethylpenicillin, also called Penicillin V |
| Class | Penicillin antibacterial |
| Common forms | 250 mg tablet; 125 mg/5 ml oral suspension |
| Key uses | Streptococcal pharyngitis, scarlet fever, and diphtheria completion therapy |
| Treatment duration | 10 days for streptococcal pharyngitis or scarlet fever; 14 days for diphtheria in the source guidance |
| Major caution | Penicillin allergy and cephalosporin cross-sensitivity history |
| Monitoring | Allergic reaction, diarrhoea, nausea, renal impairment, and treatment response |
Clinical context from Kenza
The sections below add practical explanation around the source-derived monograph. They are educational context and do not replace local protocols or clinician review.
Phenoxymethylpenicillin and Penicillin V are the same medicine
The long name phenoxymethylpenicillin and the shorter name Penicillin V refer to the same oral penicillin medicine. Including both names helps readers match prescriptions, formularies, and guideline wording.
Why completing the course matters
The source guidance gives defined treatment durations for streptococcal pharyngitis, scarlet fever, and diphtheria. Stopping early can allow infection to persist or recur.
Allergy history comes first
Penicillin allergy can be serious. A history of immediate allergy, severe rash, breathing difficulty, swelling, or anaphylaxis should be reviewed before any penicillin is used.
Therapeutic action
Penicillin antibacterial.
Indications
- Streptococcal pharyngitis and scarlet fever.
- Alternative to first-line antibiotic treatment of diphtheria.
- Completion treatment following parenteral therapy with penicillin.
Forms and strengths
- 250 mg tablet (400,000 IU).
- Powder for oral suspension, 125 mg/5 ml (200,000 IU/5 ml), to be reconstituted with filtered water and administered using a measuring device.
Dose
Streptococcal pharyngitis, scarlet fever
- Child under 1 year and under 10 kg: 125 mg 2 times daily, corresponding to 5 ml 2 times daily.
- Child 1 to under 6 years and 10 to under 21 kg: 250 mg 2 times daily, corresponding to 10 ml 2 times daily.
- Child 6 to under 12 years and 21 to under 39 kg: 500 mg 2 times daily, corresponding to 20 ml 2 times daily or 2 tablets 2 times daily.
- Age 12 years and over and adult, 39 kg and over: 1 g 2 times daily, corresponding to 4 tablets 2 times daily.
Diphtheria
- Child under 40 kg: 10 to 15 mg/kg, maximum 500 mg, 4 times daily.
- Child 40 kg and over and adult: 500 mg 4 times daily.
Duration
- Streptococcal pharyngitis and scarlet fever: 10 days.
- Diphtheria: 14 days.
Contra-indications, adverse effects, precautions
- Do not administer to patients with allergy to penicillin.
- Administer with caution to patients with allergy to cephalosporin because cross-sensitivity may occur, or severe renal impairment where dose reduction may be needed.
- May cause diarrhoea, nausea, and allergic reactions that may be severe.
- Do not combine with methotrexate.
- Pregnancy: no contra-indication.
- Breast-feeding: no contra-indication.
- Take between meals.
Dose and duration
| Age | Weight | Daily dose | 125 mg/5 ml oral susp. | 250 mg tablet |
|---|---|---|---|---|
| < 1 year | < 10 kg | 125 mg x 2 | 5 ml x 2 | − |
| 1 to < 6 years | 10 to < 21 kg | 250 mg x 2 | 10 ml x 2 | − |
| 6 to < 12 years | 21 to < 39 kg | 500 mg x 2 | 20 ml x 2 | 2 tab x 2 |
| ≥ 12 years and adult | ≥ 39 kg | 1 g x 2 | − | 4 tab x 2 |
Frequently Asked Questions
Phenoxymethylpenicillin = Penicillin V oral dose and administration questions
What is phenoxymethylpenicillin or Penicillin V used for?
This guide lists Penicillin V for streptococcal pharyngitis, scarlet fever, diphtheria alternative therapy, and completion treatment after parenteral penicillin.
What forms of Penicillin V oral are listed?
The listed forms are 250 mg tablets and 125 mg/5 ml powder for oral suspension after reconstitution.
Why does the page use both phenoxymethylpenicillin and Penicillin V?
Phenoxymethylpenicillin is also known as Penicillin V, so the page includes both names to help readers recognize the same medicine.
What precautions matter with Penicillin V?
The page should be used with clinician guidance, especially for allergy history, treatment indication, duration, and completion after injectable penicillin therapy.
Source
MSF Essential drugs practical guidelines (January 2026)
This page combines source-derived medicine reference sections with Kenza editorial context, while leaving out the Storage and Remarks sections from the source batch.
Additional medical references
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