nafcillin

Absorption

Following intravenous administration of 500mg nafcillin, the mean plasma concentration was approximately 30 μg/mL. This value was reached after 5 minutes of injection .

Toxicity

Serious toxicity is unlikely following large doses of nafcillin. Acute ingestion of large doses of nafcillin may cause nausea, vomiting, diarrhea and abdominal pain. Acute oliguric renal failure and hematuria may occur following large doses. The oral LD50 in rats is >5000mg/kg and the intravenous LD50 in rats is >1000mg/kg .

Originator

Unipen,Wyeth,US,1964

The Uses of nafcillin

Antibacterial.

Indications

Indicated in the treatment of infections caused by penicillinase-producing staphylococci which have demonstrated susceptibility to the drug.

Background

A semi-synthetic antibiotic related to penicillin, Naficillin is a narrow-spectrum beta-lactam antibiotic drug. It is a beta-lactamase-resistant penicillin that is indicated for the treatment of Staphylococcal infections caused by strains that are resistant to other penicillins, except those caused by MRSA. It may be used as a first-line therapy in Methicillin-Sensitive Staphylococcus aureus infections .

Definition

ChEBI: Nafcillin is a penicillin in which the substituent at position 6 of the penam ring is a (2-ethoxy-1-naphthoyl)amino group. It has a role as an antibacterial drug. It is a penicillin and a penicillin allergen. It is a conjugate acid of a nafcillin(1-).

Manufacturing Process

A stirred suspension of 12.6 grams 6-aminopenicillanic acid in 130 ml dry alcohol-free chloroform was treated with 16 ml triethylamine and then with 13.8 grams of a solution of 2-ethoxy-1-naphthoyl chloride in 95 ml chloroform. After being washed successively with 58 ml each of 1 N and then 0.1 N hydrochloric acid the chloroform solution was extracted with N aqueous sodium bicarbonate (58 ml + 6 ml). The combined bicarbonate extracts were washed with 20 ml ether and then evaporated at low temperature and pressure to give the crude sodium salt of 2-ethoxy-1-naphthylpenicillin [also called sodium 6-(2-ethoxy-1-naphthamido)penicillinate] as a yellow powder (20.3 grams). This was dissolved in 20 ml water at 30°C and diluted with 180 ml n-butanol, also at 30°C, with stirring. Slow cooling to 0°C gave colorless needles of the product.

brand name

Nallpen (GlaxoSmithKline).

Therapeutic Function

Antibacterial

Pharmacokinetics

Nafcillin is a semisynthetic antibiotic substance derived from 6-amino-penicillanic acid. The drugs in this class are highly resistant to inactivation by staphylococcal penicillinase and are active against penicillinase-producing and non penicillinase-producing strains of Staphylococcus species.

Metabolism

Hepatic metabolism accounts for less than 30% of the biotransformation of most penicillins.