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Penicillin

Group of antibiotics derived from Penicillium fungi / From Wikipedia, the free encyclopedia

Penicillins (P, PCN or PEN) are a group of antibiotics originally obtained from Penicillium moulds, principally P. chrysogenum and P. rubens. Most penicillins in clinical use are synthesised by P. chrysogenum using deep tank fermentation[1] and then purified.[2][3] A number of natural penicillins have been discovered, but only two purified compounds are in clinical use: penicillin G (intramuscular or intravenous use) and penicillin V (given by mouth). Penicillins were among the first medications to be effective against many bacterial infections caused by staphylococci and streptococci. They are members of the β-lactam antibiotics.[4] They are still widely used today for different bacterial infections, though many types of bacteria have developed resistance following extensive use.

Quick facts: Clinical data, AHFS/Drugs.com, Routes of admi...
Penicillin
Penicillin core structure, where "R" is the variable group
Clinical data
AHFS/Drugs.comMicromedex Detailed Consumer Information
Routes of
administration
Intravenous, intramuscular, by mouth
ATC code
Legal status
Legal status
  • In general: ℞ (Prescription only)
Pharmacokinetic data
MetabolismLiver
Elimination half-lifeBetween 0.5 and 56 hours
ExcretionKidneys
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About 10% of people report that they are allergic to penicillin; however, up to 90% of this group may not actually be allergic.[5] Serious allergies only occur in about 0.03%.[for whom?][5] Research highlights the importance of both doctors and patients discussing recorded penicillin allergies.[6][7] Those who are allergic to penicillin are most often given cephalosporin C (another β-lactam antibiotic) because there is only 10% crossover in allergy between the penicillins and cephalosporins.[4]

Penicillin was discovered in 1928 by Scottish scientist Alexander Fleming as a crude extract of P. rubens.[8] Fleming's student Cecil George Paine was the first to successfully use penicillin to treat eye infection (ophthalmia neonatorum) in 1930. The purified compound (penicillin F) was isolated in 1940 by a research team led by Howard Florey and Ernst Boris Chain at the University of Oxford. Fleming first used the purified penicillin to treat streptococcal meningitis in 1942.[9] For the discovery, Fleming shared the 1945 Nobel Prize in Physiology or Medicine with Florey and Chain.

Several semisynthetic penicillins are effective against a broader spectrum of bacteria: these include the antistaphylococcal penicillins, aminopenicillins and the antipseudomonal penicillins.