Pronapen 40lac

Also used in preventing Secondary bacterial Infection

Use cautiously in animals allergic to penicillin-like
drugs.

Administration of the long-acting benzathine form of procaine penicillin increases the risk of residues in food-producing animals.

Penicillins are usually bactericidal against susceptible bacteria and act by inhibiting mucopeptide synthesis in the cell wall resulting in a defective barrier and an osmotically unstable spheroplast. The exact mechanism for this effect has not been definitively determined, but beta-lactam antibiotics have been shown to bind to several enzymes (carboxypeptidases, transpeptidases, endopeptidases) within the bacterial cytoplasmic membrane that are involved with cell wall synthesis. The different affinities that various beta-lactam antibiotics have for these enzymes (also known as penicillin-binding proteins; PBPs) help explain the differences in spectrums of activity the drugs have that are not explained by the influence of beta-lactamases. Like other beta-lactam antibiotics, penicillins are generally considered more effective against actively growing bacteria. Penicillins are considered time dependent antibiotics as efficacy depends on the length of time that plasma (or tissue) concentrations exceed the MIC of pathogens.

AMINOGLYCOSIDES: In vitro studies have demonstrated that penicillins can have synergistic or additive activity against certain bacteria when used with aminoglycosides or cephalosporins.
BACTERIOSTATIC ANTIBIOTICS (e.g., chloramphenicol, erythromycin, tetracyclines): Use with penicillins is generally not recommended, particularly in acute infections where the organism is proliferating rapidly as penicillins tend to perform better on actively growing bacteria.
METHOTREXATE: Penicillins may decrease renal elimination of MTX

PROBENECID: Competitively blocks the tubular secretion of most penicillins, thereby increasing serum levels and serum half-lives.

Procaine penicillin has a high safety margin and is usually well tolerated. Allergic
reactions are possible. Diarrhea is common with oral doses, but oral forms are rarely used. Pain and tissue reactions may occur with IM or SQ injections.
Formulations of procaine penicillin contain varying amounts of free procaine
(depending on the formulation). Free procaine in the formulation may elicit a
central nervous system (CNS) reaction after injection in some horses.

 Avoid injection volumes greater than 30 mL per site.