pristinamycin

Pristinamycin is a streptogramin-class antibiotic produced by the actinomycete Streptomyces pristinaespiralis. It is used as a combination of two synergistic components, pristinamycin I (type A) and pristinamycin II (type B).

Both components bind to the 50S ribosomal subunit and inhibit protein synthesis. When used together, the two groups act synergistically to suppress bacterial growth, with the type A component enhancing the activity of the type B component.

Pristinamycin is primarily active against Gram-positive bacteria, including many staphylococci and streptococci, and some enterococci. It has limited activity against most Gram-negative organisms and is generally reserved for infections caused by susceptible strains or in patients intolerant to other therapies.

In some European countries, pristinamycin is prescribed for skin and soft-tissue infections, respiratory infections, and certain gynecological or intra-abdominal infections due to susceptible organisms. It is not widely available or approved in the United States.

Pristinamycin is typically given orally, with systemic activity when absorbed. Availability depends on national regulatory approvals and formulations.

Adverse effects are usually mild but can include gastrointestinal upset, rash, and hypersensitivity. Long-term or extensive use may be associated with hepatotoxicity in rare cases. Bacterial resistance can arise via ribosomal modifications or efflux, reducing efficacy; stewardship is advised to preserve activity.