MedeliX
Start asking

Penicillin v

Fenopen · ATC code J01CE02

Also known as: Phenoxymethylpenicillin, Fenoksimetilpenisilin, Penicillin V Potassium

Key facts
Active substance
Penicillin v
ATC code
J01CE02
Authorisation
authorised nationally; no central EU authorisation
Information as of
2026-10-29

Key facts

Penicillin V (phenoxymethylpenicillin) is, per the US prescribing information, an acid-stable oral penicillin for mild to moderately severe infections caused by penicillin-sensitive organisms.

What it is used for

  • Mild to moderately severe infections due to penicillin G-sensitive organisms, e.g. streptococcal upper respiratory tract infections, scarlet fever, mild erysipelas.
  • Pneumococcal respiratory tract infections, mild staphylococcal skin and soft tissue infections, fusospirochetosis (Vincent's infection).
  • Prevention of recurrence after rheumatic fever and/or chorea, and endocarditis prophylaxis in certain heart conditions.
  • Severe pneumonia, empyema, bacteremia, pericarditis, meningitis and arthritis should not be treated with it during the acute stage.

Dosing

  • Adults and children 12 years and over, streptococcal infections: 125 to 250 mg every 6 to 8 hours for 10 days (a 10-day minimum is needed to eliminate the organism).
  • Pneumococcal infections (including otitis media): 250 to 500 mg every 6 hours until the patient has been afebrile for at least 2 days.
  • Staphylococcal skin infections and fusospirochetosis: 250 to 500 mg every 6 to 8 hours.
  • Prevention of rheumatic fever recurrence: 125 mg to 250 mg twice daily on a continuing basis.
  • Endocarditis prophylaxis: see the full text for the regimen.

Contraindications

  • A previous hypersensitivity reaction to any penicillin.

Important warnings

  • Serious and occasionally fatal anaphylactic reactions, more likely with a history of penicillin hypersensitivity or sensitivity to multiple allergens; possible with oral use too.
  • Clostridium difficile-associated diarrhea, even two or more months after treatment.
  • Use with caution in people with significant allergies and/or asthma.
  • The oral route should not be relied on in severe illness, nausea, vomiting or disturbed gastrointestinal function.
  • Prolonged use may promote overgrowth of nonsusceptible organisms, including fungi.

Side effects

  • Most common: nausea, vomiting, epigastric distress, diarrhea and black hairy tongue.
  • Hypersensitivity: skin eruptions up to exfoliative dermatitis, urticaria, serum-sickness-like reactions, laryngeal edema, anaphylaxis; fever and eosinophilia may be the only reaction.
  • Infrequent, usually with high-dose parenteral penicillin: hemolytic anemia, leukopenia, thrombocytopenia, neuropathy, nephropathy.

Summary of the official product information, written with AI on 2026-10-29. Every number was checked automatically against the original text. Not reviewed by a physician – the full official text is authoritative.

Full official text →

Common questions – ask Medelix

For patients

Patient information (US)

This product has no separate US patient information.

Authorisation and brand names by country

Medicines with exactly this active-substance composition, as listed in the national registers – alphabetical and without ranking. Whether a product is currently available is not shown here.

Turkey

  • FenopenBİLİM İLAÇ SAN. VE TİC. A.Ş. · 2 register entries

Source: TİTCK – Ruhsatlı Beşeri Tıbbi Ürünler Listesi, as of 2026-10-16

Medelix receives no money from pharmaceutical companies. Brand names are listed alphabetically and without ranking.

Related calculators

Another question about this substance?

Medelix answers clinical questions from guidelines, studies and product information – every claim with its source.

Sources

  1. U.S. Food and Drug Administration. Penicillin V Potassium (NorthStar Rx LLC) – Prescribing Information, 2022-10-28. DailyMed (NLM), 2026-10-29. https://dailymed.nlm.nih.gov/dailymed/lookup.cfm?setid=ec25ce45-c0b2-45fa-9211-77f283aad4bd
  2. TİTCK – Ruhsatlı Beşeri Tıbbi Ürünler Listesi, 2026-10-16. https://www.titck.gov.tr/dinamikmodul/85

Editorial: Medelix editorial team · last updated 2026-10-29 · How these pages are made · Report an error

Source: U.S. Food and Drug Administration (FDA), prescribing information, via DailyMed (NLM); public domain. Not advertising, not a treatment recommendation. For questions about your own treatment, ask your doctor or pharmacist.