Fortaz Dosage

Generic name: CEFTAZIDIME 100mg in 1mL
Dosage form: injection, powder, for solution
Drug class: Third generation cephalosporins

Medically reviewed by Drugs.com. Last updated on Jul 18, 2023.

Dosage

The usual adult dosage is 1 gram administered intravenously or intramuscularly every 8 to 12 hours. The dosage and route should be determined by the susceptibility of the causative organisms, the severity of infection, and the condition and renal function of the patient.

The guidelines for dosage of FORTAZ® are listed in Table 3. The following dosage schedule is recommended.

Table 3. Recommended Dosage Schedule
* Although clinical improvement has been shown, bacteriologic cures cannot be expected in patients with chronic respiratory disease and cystic fibrosis. † The higher dose should be reserved for immunocompromised pediatric patients or pediatric patients with cystic fibrosis or meningitis.
	Dose	Frequency
Adults
Usual recommended dosage	1 gram intravenous or intramuscular	every 8 to 12 hours
Uncomplicated urinary tract infections	250 mg intravenous or intramuscular	every 12 hours
Bone and joint infections	2 grams intravenous	every 12 hours
Complicated urinary tract infections	500 mg intravenous or intramuscular	every 8 to 12 hours
Uncomplicated pneumonia; mild skin and skin-structure infections	500 mg to 1 gram intravenous or intramuscular	every 8 hours
Serious gynecologic and intra-abdominal infections	2 grams intravenous	every 8 hours
Meningitis	2 grams intravenous	every 8 hours
Very severe life-threatening infections, especially in immunocompromised patients	2 grams intravenous	every 8 hours
Lung infections caused by Pseudomonas spp. in patients with cystic fibrosis with normal renal function*	30 to 50 mg/kg intravenous to a maximum of 6 grams per day	every 8 hours
Neonates (0-4 weeks)	30 mg/kg intravenous	every 12 hours
Infants and children (1 month-12 years)	30 to 50 mg/kg intravenous to a maximum of 6 grams per day†	every 8 hours

Impaired Hepatic Function

No adjustment in dosage is required for patients with hepatic dysfunction.

Impaired Renal Function

Ceftazidime is excreted by the kidneys, almost exclusively by glomerular filtration. Therefore, in patients with impaired renal function (glomerular filtration rate [GFR] <50 mL/min), it is recommended that the dosage of ceftazidime be reduced to compensate for its slower excretion. In patients with suspected renal insufficiency, an initial loading dose of 1 gram of FORTAZ® may be given. An estimate of GFR should be made to determine the appropriate maintenance dosage. The recommended dosage is presented in Table 4.

Table 4. Recommended Maintenance Dosages of FORTAZ® in Renal Insufficiency
NOTE: IF THE DOSE RECOMMENDED IN Table 3 ABOVE IS LOWER THAN THAT RECOMMENDED FOR PATIENTS WITH RENAL INSUFFICIENCY AS OUTLINED IN Table 4, THE LOWER DOSE SHOULD BE USED.
Creatinine Clearance (mL/min)	Recommended Unit Dose of FORTAZ®	Frequency of Dosing
50-31	1 gram	every 12 hours
30-16	1 gram	every 24 hours
15-6	500 mg	every 24 hours
less than 5	500 mg	every 48 hours

When only serum creatinine is available, the following formula (Cockcroft's equation)1 may be used to estimate creatinine clearance. The serum creatinine should represent a steady state of renal function:

Males: Creatinine clearance (mL/min) =

Weight (kg) x (140 - age)

72 x serum creatinine (mg/dL)

Females: 0.85 x male value

In patients with severe infections who would normally receive 6 grams of FORTAZ daily were it not for renal insufficiency, the unit dose given in the table above may be increased by 50% or the dosing frequency may be increased appropriately. Further dosing should be determined by therapeutic monitoring, severity of the infection, and susceptibility of the causative organism.

In pediatric patients as for adults, the creatinine clearance should be adjusted for body surface area or lean body mass, and the dosing frequency should be reduced in cases of renal insufficiency.

In patients undergoing hemodialysis, a loading dose of 1 gram is recommended, followed by 1 gram after each hemodialysis period.

FORTAZ can also be used in patients undergoing intraperitoneal dialysis and continuous ambulatory peritoneal dialysis. In such patients, a loading dose of 1 gram of FORTAZ may be given, followed by 500 mg every 24 hours. In addition to IV use, FORTAZ can be incorporated in the dialysis fluid at a concentration of 250 mg for 2 L of dialysis fluid.

Note: Generally FORTAZ should be continued for 2 days after the signs and symptoms of infection have disappeared, but in complicated infections longer therapy may be required.

Administration

FORTAZ may be given intravenously or by deep IM injection into a large muscle mass such as the upper outer quadrant of the gluteus maximus or lateral part of the thigh. Intra-arterial administration should be avoided (see PRECAUTIONS).

Intramuscular Administration

For IM administration, FORTAZ should be constituted with one of the following diluents: Sterile Water for Injection, Bacteriostatic Water for Injection, or 0.5% or 1% Lidocaine Hydrochloride Injection. Refer to Table 5.

Intravenous Administration

The IV route is preferable for patients with bacterial septicemia, bacterial meningitis, peritonitis, or other severe or life-threatening infections, or for patients who may be poor risks because of lowered resistance resulting from such debilitating conditions as malnutrition, trauma, surgery, diabetes, heart failure, or malignancy, particularly if shock is present or pending.

For direct intermittent IV administration, constitute FORTAZas directed in Table 5 with Sterile Water for Injection. Slowly inject directly into the vein over a period of 3 to 5 minutes or give through the tubing of an administration set while the patient is also receiving one of the compatible IV fluids (see COMPATIBILITY AND STABILITY).

For IV infusion, constitute the 500-mg, 1-gram, or 2-gram vial and add an appropriate quantity of the resulting solution to an IV container with one of the compatible IV fluids listed under the COMPATIBILITY AND STABILITY section.

Intermittent IV infusion with a Y-type administration set can be accomplished with compatible solutions. However, during infusion of a solution containing ceftazidime, it is desirable to discontinue the other solution.

Table 5. Preparation of Solutions of FORTAZ
* To obtain a dose of 500 mg, withdraw 5 mL from the vial following reconstitution. † To obtain a dose of 1 g, withdraw 10 mL from the vial following reconstitution. ‡ To obtain a dose of 2 g, withdraw 11.5 mL from the vial following reconstitution.
Size	Amount of Diluent to be Added (mL)	Approximate Available Volume (mL)	Approximate Ceftazidime Concentration (mg/mL)
Intramuscular
500-mg vial	1.5	1.8	280
1-gram vial	3	3.6	280
Intravenous
500-mg vial	5.3	5.7*	100
1-gram vial	10	10.8†	100
2-gram vial	10	11.5‡	170

All vials of FORTAZ as supplied are under reduced pressure. When FORTAZ is dissolved, carbon dioxide is released and a positive pressure develops. For ease of use please follow the recommended techniques of constitution described on the detachable Instructions for Constitution section of this insert.

Solutions of FORTAZ, like those of most beta-lactam antibacterial drugs, should not be added to solutions of aminoglycoside antibacterial drugs because of potential interaction.

However, if concurrent therapy with FORTAZ and an aminoglycoside is indicated, each of these antibacterial drugs can be administered separately to the same patient.