Benzylpenicillin Sodium for Injection

[Veterinary Drug name]                      Rx

Generic name: Benzylpenicillin Potassium For Injection

Product Name:

Benzylpenicillin Potassium for Injection

Chinese Pinyin :Zhusheyong Qingmeisujia

[Main ingredients] Potassium penicillin

[Character] This product is a white crystalline powder.

Penicillin is a bactericidal antibiotic with strong antibacterial activity. Its antibacterial mechanism is mainly to inhibit the synthesis of bacterial cell wall mucopeptides. The sensitive bacteria in the growth phase have vigorous division and the cell wall is in the biosynthetic stage. Under the action of penicillin, the synthesis of mucopeptide is blocked and the cell wall cannot be formed, which leads to cell membrane rupture and death under osmotic pressure. Non-growth and reproduction period of bacteria, at this time do not need to synthesize the cell wall, penicillin does not have a bactericidal effect, should not be penicillin this kind of "reproductive period fungicide" and inhibit the growth and reproduction of bacteria "rapid antibacterial agents" (such as florfenicol, tetracycline, erythromycin, etc.) combined. The latter makes the bacteria in a state of growth inhibition, resulting in penicillin can not play a role.

Penicillin is a narrow-spectrum antibiotic, which is mainly effective against a variety of Gram-positive bacteria and a few Gram-negative bacteria. The main sensitive bacteria are Staphylococcus, Streptococcus, swine erysipilibacterium, Corynebacterium, Clostridium tetani, Actinomyces, Bacillus anthracis, Spirochetes and so on. They were not susceptible to mycobacteria, Mycoplasma, Chlamydia, Rickettsia, nocardia, fungi and viruses.

Pharmacokinetics Penicillin potassium salt was absorbed rapidly after intramuscular injection, and the peak plasma concentration was reached in 15-30 minutes. The plasma concentration of penicillin potassium salt maintained above 0.5μg/ml for 6 to 7 hours after intramuscular injection. Penicillin is widely distributed in all tissues of the body and can enter the fetal circulation, with higher concentrations in the kidney, liver, lung, muscle, small intestine and spleen. Low levels in bone, saliva and milk. It is difficult to enter the cerebrospinal fluid, and its concentration in normal cerebrospinal fluid is only 1%-3% of the blood concentration, and its concentration in cerebrospinal fluid can reach 5%-30% of the blood concentration during inflammation. The concentration of penicillin in breast milk can be 5%-20% of the blood concentration. "When penicillin is injected into the milk, it is largely absorbed in the first few hours, but the antimicrobial concentration in the milk can be maintained for a considerable time." It has been reported that 100 000 units of aqueous penicillin solution injected into the milk retains 4.26 units /ml in milk up to 24 hours.

Penicillin is metabolized to a small extent in the liver and excreted mostly in its original form. Under normal renal function, 50%-75% of penicillin is excreted from the kidney, 90% of which is secreted through the renal tubules. Because of rapid excretion, it is eliminated quickly in the body. The plasma protein binding rate of penicillin is about 50%. The half-life is short with little variation among species, ranging from 0.5 to 1.2 hours for all domestic animals. The apparent volume of distribution is also small, generally 0.2 to 0.3L/kg, with higher plasma concentrations and lower tissue concentrations.

[Drug interactions] (1) The combination of penicillin and aminoglycosides can increase the concentration of aminoglycosides in the bacteria, showing a synergistic effect.

(2) Fast acting antibacterial agents such as macrolides, tetracyclines and amide alcohols interfere with the bactericidal activity of penicillin and should not be used in combination.

(3) Heavy metal ions (especially copper, zinc, mercury), alcohols, acids, iodine, oxidants, reducing agents, hydroxyl compounds, acidic glucose injection or tetracycline hydrochloride injection can destroy the activity of penicillin, and it is prohibited to be used in combination.

(4) Amines and penicillin can form insoluble salts, which can delay the absorption of penicillin, such as procaine penicillin.

(5) Potassium penicillin aqueous solution and some drug solutions (such as chlorpromazine hydrochloride, lincomycin hydrochloride, norepinephrine tartrate, oxytetracycline hydrochloride, tetracycline hydrochloride, B vitamins and vitamin C) should not be mixed, otherwise it can produce turbidity, flocculence or precipitation.

[Action and use] β-lactam antibiotics. It is mainly used for Gram-positive bacteria infection, and also for actinomycetes and Leptospira infections.

[Usage and dosage] in terms of potassium penicillin. Intramuscular injection: one dose, per lkg body weight, horse, cattle 10,000 ~ 20,000 units; 20,000 ~ 30,000 units for sheep, pigs, foals and calves; Poultry 50,000 units; And 30,000 to 40,000 units for dogs and cats. 2 to 3 times a day for 2 to 3 days.

Before use, add an appropriate amount of sterilized water for injection to dissolve.

[Adverse reactions] (1) Mainly allergic reactions, most of the domestic animals can occur, but the incidence is low. The local reactions were edema and pain at the injection site, and the systemic reactions were urticaria and rash. In severe cases, it could cause shock or death.

(2) In some animals, penicillin can induce superinfection of the gastrointestinal tract.

[Precautions] (1) Poultry that has laid eggs for human consumption should not be used during the laying period.

(2) Potassium penicillin is easily soluble in water, the aqueous solution is unstable, and easily hydrolyzed. The hydrolysis rate accelerates with the increase of temperature, so the injection should be prepared before clinical use. When necessary, it should be placed in the refrigerator (2-8 ° C), which can be stored for 7 days, and can only be stored for 24 hours at room temperature.

(3) The interaction and incompatibility with other drugs should be understood so as not to affect the efficacy of penicillin.

(4) Hyperkalemia may occur with large dose injection. It will have adverse consequences on animals with renal insufficiency or cardiac insufficiency, and the adverse effect of potassium ion on the heart is more serious.

(5) In the treatment of tetanus, it should be combined with tetanus antitoxin.

[off-drug period] 0 days for cattle, sheep, pigs and poultry; The milking period is 72 hours.

[Specification] According to C₁₆H₁₇KN₂O₄S (1)0.25g(400,000 units)(2)0.5g(800,000 units)(3)0.625g

(1 million units)(4)1.0g(1.6 million units)(5)2.5g(4 million units)

[ Storage ] Closed, stored in a cool, dark and dry place.