Significant drug–drug interaction between warfarin and nafcillin

Nafcillin, a beta-lactam semisynthetic penicillin, is highly resistant to penicillinase and is similar to other penicillins except that it is primarily metabolized in the liver. It is believed that nafcillin causes CYP3A4 enzyme induction which decreases warfarin’s half-life. The onset of CYP3A4 induction by nafcillin occurs within the first 7 days, but maximal effects may take up to 2 weeks. Once nafcillin is discontinued, the effects persist for several weeks. A 79-year-old male with a history of atrial fibrillation and a 53-year-old male with a history of recurrent venous thromboembolism required significantly higher weekly warfarin doses during courses of nafcillin therapy. Both patients required a 2.5–3.5-fold increase from their baseline weekly warfarin dose to achieve therapeutic international normalized ratios (INRs) while on nafcillin. Traditional protocol-driven warfarin management can result in suboptimal anticoagulation in patients on warfarin and nafcillin.

DEVELOPMENT AND VALIDATION OF A HIGH PERFORMANCE LIQUID CHROMATOGRAPHY (HPLC) ANALYTICAL METHOD FOR DETERMINATION OF AMOXICILLIN IN CAPSULES

Amoxicillin, substance-related to semisynthetic penicillin, has been widely used to treat infections caused by various microorganisms, however reports of suitable methods for the quantitative determination and indicative of the stability of formulations containing this substance are rare. Due to lack of studies on the forced degradation of the substance and on the need to monitor the quality of this type of formulation was proposed and validated a method for the determination of amoxicillin content in capsules by high-performance liquid chromatography - HPLC for the quality control of amoxicillin capsules, allowing the provision of useful information about the characteristics of this type of formulation and its stability. The method was validated for parameters of linearity, specificity, accuracy, precision, and robustness

Kloning Gen pcbC dari Penicillium chrysogenum ke dalam Plasmid pPICZA untuk Pengembangan Produksi Penisilin G

Availability of drugs in Indonesia is still limited by the high prices of drugs due to on the imported raw materials that reaches 95%. Developing antibiotic raw materials can be achieved by increasing of penicillin G production, which is the raw material for the formation of semisynthetic penicillin derivatives through the production of 6-aminopenisillanic acid (6-APA). One of the important enzyme in the penicillin G biosynthesis is Isopenisilin N Synthase (IPNS) that encodes by pcbC gene on Penicillium chrysogenum. This study aimed to obtain a recombinant of pcbC gene fragments that is inserted into pPICZA plasmid. Amplification of pcbC gene used pcbC-F and pcbC-R primers. The pcbC gene fragment was inserted into pPICZA vector and then transformed into TOP 10 F’. The results showed that the recombinant of the pcbC gene fragment from P. chrysogenum has been obtained. Analysis of DNA sequences using the BLAST program showed that the pcbC gene fragment has high homology (99%) with the pcbC gene from P. chrysogenum Wisconsin 54-1255 and P. chrysogenum AS-P-78 which encodes IPNS Keywords: pcbC Gene, Penicillium chrysogenum, cloning, penicillin G

Erratum

Regarding the article on Pencillin in Pediatrics in Review. 1995;16:83-90 (March), a reader expressed concern about the answers to the first and second questions in the PIR Quiz. In the first question, the clinical picture presented was clearly meningococcemia, and aqueous penicillin G IV is the drug of choice. However, as Dr. Feigin states, "Given the choices in question #2, we would probably choose methicillin because the question suggests that Staphylococcus aureus may be the offending organism. Of the various semisynthetic penicillin derivatives listed, methicillin is the one with the lowest degree of protein binding (20%) and, thus, is least likely to displace bilirubin from albumin binding sites. Therefore, its use in the newborn period may be indicated."