Phenoxymethylpenicillin

Phenoxymethylpenicillin

File:Penicillin-V-2D-skeletal.png
Systematic (IUPAC) name
(2S,5R,6R)-3,3-dimethyl-7-oxo-6- [(phenylacetyl)amino]- 4-thia-1-azabicyclo[3.2.0] heptane-2-carboxylic acid
Clinical data
[[Regulation of therapeutic goods |Template:Engvar data]]	US DailyMed: 2658
Pregnancy category	US: B (No risk in non-human studies)
Routes of administration	enteral
Legal status
Legal status	℞ (Prescription only)
Pharmacokinetic data
Bioavailability	60%
Protein binding	80%
Metabolism	hepatic
Biological half-life	30–60 min
Excretion	renal
Identifiers
CAS Number	87-08-01 , 132-98-9 (potassium), 147-48-8 (anhydrous calcium), 73368-74-8 (calcium dihydrate)
ATC code	J01CE02
PubChem	CID 6869
DrugBank	DB00417
Chemical data
Formula	C16H18N2O5S
Molar mass	350.39 g/mol[[]]

Phenoxymethylpenicillin, commonly known as penicillin V, is the orally active form of penicillin, an antibiotic. It is less active than benzylpenicillin, however, and is appropriate only in conditions where high tissue concentrations are not required. Phenoxymethylpenicillin exerts a bactericidal action against penicillin sensitive microorganisms during the stage of active multiplication. It acts through the inhibition of biosynthesis of cell-wall Peptidoglycan. It is not active against the Beta-lactamase-producing bacteria, which include many strains of staphylococci.

Phenoxymethylpenicillin has a range of antimicrobial activity similar to that of benzylpenicillin and a similar mode of action. It may be less active against some susceptible organisms, particularly Gram-negative bacteria. The mechanisms and patterns of resistance to phenoxymethylpenicillin are similar to those of benzylpenicillin.

It is used only for the treatment of mild to moderate infections, and not for chronic, severe, or deep-seated infections since absorption can be unpredictable. Therapy should be guided by bacteriological studies (including sensitivity tests) and by clinical response. Patients treated initially with parenteral benzylpenicillin may continue oral treatment with phenoxymethylpenicillin once a satisfactory clinical response has been obtained.

Indications

Specific indications for phenoxymethylpenicillin include:

• Infections caused by Streptococcus pyogenes
  • Tonsillitis
  • Pharyngitis
  • Skin infections
• Anthrax (mild uncomplicated infections)
• Lyme disease (early stage in pregnant women or young children)
• Pharyngitis or tonsillitis
• Rheumatic fever (primary and secondary prophylaxis)
• Streptococcal skin infections
• Spleen disorders (pneumococcal infection prophylaxis)
• Moderate-to-severe gingivitis (with metronidazole)
• Avulsion injuries of teeth (as an alternative to Tetracycline)

Penicillin V is the first choice in the treatment of odontogenic infections.

Adverse Effects and Precautions

Phenoxymethylpenicillin is usually well tolerated but may occasionally cause transient nausea, vomiting, epigastric distress, diarrhea, and black hairy tongue. A previous hypersensitivity reaction to any penicillin is a contraindication.

Compendial status

• British Pharmacopoeia

See also

• Drug allergy

da:Phenoxymethylpenicillin zh:青霉素V钾