4

Golden oldies - the penicillins retain a place in therapy 50 years after their discovery

The peak of gonococcal resistance to penicillins was reached in 1983 and now appears to be declining, while most pneumococci remain penicillin-sensiti ve. Pneumococcal, meningococcal, Streptococcus pyogenes and Treponema pal/idum infections remain targets for benzylpenicillin [penicillin G] treatment, as do leptospirosis and Lyme borreliosis. The aminopenicillins can be used in the treatment of middle ear, sinus, lower respiratory tract and systemic infections caused by meningococci, pneumococci, Haemophilus injluenzae, some Gram-negative enteric bacilli and Salmonella spp.

Penicillinase-resistant agents, such as methicillin, have become ' ... the mainstay of . ant;staphylococcal treatment • •. ' , although some Staphylococcus aureus strains are resistant. Another approach to the problem of penicillinase-producing strains has involved the use of enzyme inhibitors such as clavulanic acid, which extend the spectra of activity of the penicillins.

Antipseudomonal penicillins have now been developed, including carbenicillin and ticarcillin, and these agents can be used in the empirical treatment of febrile neutropenic patients, although an aminoglycoside is usually required concomitantly to provide cover against Pseudomonas aeruginosa. Ureidopenicillins, active against many Gram-positive and Gram­negative bacteria also usually require coadministration of an aminoglycoside when administered to febrile neutropenic patients.

Knowledge of the relationship between anti­infective structure and bacterial sensitivity/ resistance mechanisms, coupled with adequate clinical testing, has kept the penicillins in the clinical picture. Finch R. The penicillins today. Use is now well defined by clinical trials. British Medical Journal 300: 1289.1290. 19 May 1990 ""

_ 9 J"" 1990 INPHARMAIJ) ISSN 0156·1703/90/0609-0001/0$01.00/0 ~ Adi! I"ter"ational Ltd