[13] People treated initially with parenteral benzylpenicillin may continue treatment with phenoxymethylpenicillin by mouth once a satisfactory response has been obtained.

[13] Phenoxymethylpenicillin is usually well tolerated but may occasionally cause transient nausea, vomiting, epigastric distress, diarrhea, constipation, acidic smell to urine and black hairy tongue.

It exerts a bactericidal action against penicillin-sensitive microorganisms during the stage of active multiplication.

[14] The Austrian pharmaceutical company, Biochemie, was founded in Kundl in July 1946 at the site of a derelict brewery, at the suggestion of a French officer, Michel Rambaud (a chemist), who was able to obtain a small amount of Penicillium start culture from France.

Phenoxyethanol was fermented to phenoxyacetic acid[16] in the tanks, which was then incorporated into penicillin via biosynthesis.

Importantly, Brandl realised that phenoxymethylpenicillin is not destroyed by stomach acid and can therefore be given by mouth.

Phenoxymethyl penicillin was originally discovered by Eli Lilly in 1948 as part of their efforts to study penicillin precursors, but was not further exploited, and there is no evidence that Lilly understood the significance of their discovery at the time.