Cefazolin is intended only for parenteral administration - intramuscularly and intravenously (either jet or drip). Doses are set individually, taking into account the severity of the course and localization of the infection, the sensitivity of the pathogen.
Preparation of solutions and application:
Intramuscularly. A solution for intravenous injections is prepared by dissolving the dry matter in a 0.5% solution of lidocaine or in 2-3 ml of water for injection.
For intravenous fluid administration, the powder is dissolved in 10 ml of sterile water for injection (at least 4 ml of solvent per 1 gram of dry matter).
In both cases, after adding the solvent, the vial must be vigorously shaken to completely dissolve the powder.
Doses up to 1 g of cefazolin can be administered as a slow intravenous infusion (in 3-5 minutes).If higher doses are used, infusion should be used (for a period longer than 20 and up to 30 minutes). For the preparation of the infusion solution, 100-150 ml of a 0.9% sodium chloride solution, 5% or 10% dextrose or dextrose solution with 0.9% sodium chloride solution, as well as a dextrose solution in Ringer's solution, 5% or a 10% solution of fructose in sterile water for injection, Ringer's injection solution and a 0.9% solution of sodium chloride, sodium bicarbonate. The drug is diluted in 50-100 ml of 5-10% dextrose solution, 0.9% sodium chloride solution, Ringer's solution, 5% sodium bicarbonate solution.
Use only freshly prepared and clear solutions. The possible yellowish color of the solution after dissolving the powder is not an indication of any change in the properties of the preparation or of differences in its therapeutic effectiveness.
Dosing instructions for adults:
| Type of infection | Dose | Frequency of administration |
| Infections of the lung course caused by sensitive Gram-positive cocci | 250-500 mg | Every 8 hours |
| Pneumococcal pneumonia | 0.5 g | In 12 hours |
| Acute uncomplicated urinary tract infections | 1 g | In 12 hours |
| Moderately heavy or heavy | 0.5-1 g | After 6-8 hours |
| Severe, life-threatening infections: endocarditis, septicemia | 1-1.5 g | In 6 hours |
Use in children with normal renal function:
Children from 1 month and older are prescribed - 25-50 mg / kg / day; the frequency of administration is 3-4 times a day. In severe infection, the dose can be increased to 100 mg / kg body weight.
Use in patients with impaired renal function:
Patients with impaired renal function require a change in the dosage regimen in accordance with the values of CC: with a CC of 55 ml / min or more, or with a plasma creatinine concentration of 1.5 mg% or less, a full dose can be administered; with SC 54-35 ml / min or a plasma creatinine concentration of 3-1.6 mg%, a full dose can be administered, but the intervals between injections should be increased to 8 hours; with SC 34-11 ml / min or creatinine concentration in plasma 4.5-3.1 mg% - 1/2 dose at intervals of 12 hours; with CC 10 ml / min or less, or with a plasma creatinine concentration of 4.6 mg% or more - 1/2 of the usual dose every 18-24 hours. All recommended doses are administered after the initial dose corresponding to the indication and severity of the infection.
Children who have a creatinine clearance of 70 to 40 ml / min / 1.73 m2, 60% of the average daily dose of cefazolin, divided into two injections, is administered.
Children who have a creatinine clearance of 40 to 20 ml / min / 1.73 m2, 25% of an average daily dose of cefazolin, divided into two injections, is administered. In the case of creatinine clearance, 10% of the average daily dose of cefazolin is given between 20 and 5 ml / min / 1.73 m at intervals of 24 hours. All recommended doses are administered after the initial dose corresponding to the severity of the infection.
Preoperative prophylaxis:
To prevent infections during surgical interventions, the dosage of cefazolin depends on the type and duration of the operation.
- 1 gram is administered intravenously or intramuscularly for 30 minutes - 1 hour before the beginning of the surgery (the dose is sufficient for minor surgical interventions of short duration);
- with prolonged surgical operations (more than 2 hours), in addition, from 0.5 g to 1 g intravenously or intramuscularly during the operation itself (depending on the duration, it can also be administered during a surgical operation at regular intervals);
- during the postoperative period after the initial dose, doses of 0.5 g to 1 g are administered intravenously or intramuscularly with an interval of 6-8 hours for 24 hours;
- if a potential infection can pose a threat to the patient (for example, after heart surgery or after extensive orthopedic operations, such as arthroplasty), it is recommended to continue the post-operative administration of cefazolin for a period of 3 to 5 days. It is important to comply with the above dates so that sufficient concentrations of antibiotic are already present in the serum and tissues of the patient during the surgical incision.