Penisilliinit

Penisilliinit is the Finnish term for penicillin antibiotics, a group of beta-lactam medicines derived from Penicillium fungi. They are among the oldest and most widely used antibiotics for treating bacterial infections.

Penicillins act by inhibiting bacterial cell wall synthesis. They bind to penicillin-binding proteins, preventing cross-linking of peptidoglycan, and are typically bactericidal against susceptible organisms.

Classification includes narrow-spectrum agents such as penicillin G and penicillin V; broader agents like amoxicillin and ampicillin; and extended-spectrum or anti-pseudomonal penicillins such as piperacillin. Many penicillins are combined with beta-lactamase inhibitors to counter bacterial resistance.

Penicillins can be administered orally, intramuscularly, or intravenously, depending on the compound. They are largely excreted by the kidneys, and dose adjustments may be required in kidney impairment.

Common clinical uses include treatment of streptococcal infections, certain meningitis caused by susceptible organisms, some dental and skin infections, and syphilis. They are also used for prophylaxis in rheumatic fever and in some dental procedures.

Adverse effects include allergic reactions and hypersensitivity, rash, and gastrointestinal upset. Clostridioides difficile infection can occur with broad-spectrum use. Resistance arises through beta-lactamase enzymes and alterations of penicillin-binding proteins.

History: penicillin was discovered by Alexander Fleming in 1928 after mold contamination of a bacterial culture; it was later isolated and developed by Howard Florey and Ernst Boris Chain, leading to widespread clinical use in the 1940s.