The reason is that the US FDA incorrectly assumed that the potency of penicillin V is the same mole-for-mole as penicillin G. In fact, penicillin V is less potent than penicillin G, and the current penicillin V unit reflects that fact. First international unit of penicillin V (1959). One unit of penicillin V was defined as 0.590 micrograms of a reference standard held at Mill Hill in London. This unit is now obsolete.A similar standard was also established for penicillin K.

Types
Natural penicillins
Penicillin G (benzylpenicillin) was first produced from a penicillium fungus that occurs in nature. The strain of fungus used today for the manufacture of penicillin G was created by genetic engineering to improve the yield in the manufacturing process. None of the other natural penicillins (F, K, N, X, O, U1 or U6) are currently in clinical use. Semi-synthetic penicillin
Penicillin V (phenoxymethylpenicillin) is produced by adding the precursor phenoxyacetic acid to the medium in which a genetically modified strain of the penicillium fungus is being cultured. Antibiotics created from 6-APA
There are three major groups of other semi-synthetic antibiotics related to the penicillins. They are synthesised by adding various side-chains to the precursor 6-APA, which is isolated from penicillin G. These are the antistaphylococcal antibiotics, broad-spectrum antibiotics, and antipseudomonal antibiotics. Antistaphylococcal antibiotics
Cloxacillin (by mouth or by injection)
Dicloxacillin (by mouth or by injection)
Flucloxacillin (by mouth or by injection)
Methicillin (injection only)
Nafcillin (injection only)
Oxacillin (by mouth or by injection)Antistaphylococcal antibiotics are so-called because they are resistant to being broken down by staphylococcal penicillinase.
Actinic granuloma is a cutaneous condition characterized histologically by a dermal infiltrate of macrophages. : 706 Actinic granuloma is an asymptomatic granulomatous reaction that affects sun-exposed skin, most commonly on the face, neck, and scalp. It is characterized by annular or polycyclic lesions that slowly expand centrifugally and have an erythematous elevated edge and a hypopigmented, atrophic center. Advise to reduce exposure to the sun and to use sunscreen. Treatment with topical halometasone cream, pimecrolimus cream. See also
Annular elastolytic giant cell granuloma
Skin lesion
List of cutaneous conditions

References


== External links ==