First Generation Cephalosporins

Microbiology:
In vitro tests demonstrate that the cephalosporins are bactericidal because of their inhibition of cell-wall synthesis. Cefadroxil has been shown to be active against the following organisms both in vitro and in clinical infections:

• Beta-hemolytic streptococci
• Staphylococci, including penicillinase-producing strains
• Streptococcus (Diplococcus)pneumoniae
• Escherichia coli
• Proteus mirabilis
• Klebsiella species
• Moraxella (Branhamella)catarrhalis

Note: Most strains of Enterococcus faecalis (formerly Streptococcus faecalis) and Enterococcus faecium (formerly Streptococcus faecium) are resistant to cefadroxil monohydrate. It is not active against most strains of Enterobacter species, Morganella morganii (formerly Proteus morganii), and P. vulgaris. It has no activity against Pseudomonas species and Acinetobacter calcoaceticus (formerly Mima and Herellea species).

INDICATIONS AND USAGE:
Cefadroxil monohydrate is indicated for the treatment of patients with infection caused by susceptible strains of the designated organisms in the following diseases:
Urinary tract infections caused by E. coli, P. mirabilis, and Klebsiella species.

Skin and skin structure infections caused by staphylococci and/or streptococci.

Pharyngitis and/or tonsillitis caused by Streptococcus pyogenes (Group A beta-hemolytic streptococci).

Note: Only penicillin by the intramuscular route of administration has been shown to be effective in the prophylaxis of rheumatic fever. Cefadroxil monohydrate is generally effective in the eradication of streptococci from the oropharynx. However, data establishing the efficacy of cefadroxil monohydrate for the prophylaxis of subsequent rheumatic fever are not available.

Note: Culture and susceptibility tests should be initiated prior to and during therapy. Renal function studies should be performed when indicated.

DOSAGE AND ADMINISTRATION:
Cefadroxil is acid-stable and may be administered orally without regard to meals. Administration with food may be helpful in diminishing potential gastrointestinal complaints occasionally associated with oral cephalosporin therapy.

Adults
Urinary Tract Infections: For uncomplicated lower urinary tract infections (i.e., cystitis) the usual dosage is 1 or 2 g per day in a single (q.d.) or divided doses (b.i.d.).

For all other urinary tract infections the usual dosage is 2 g per day in divided doses (b.i.d.).

Skin and Skin Structure Infections: For skin and skin structure infections the usual dosage is 1 g per day in single (q.d.) or divided doses (b.i.d.).

Pharyngitis and Tonsillitis: Treatment of group A beta-hemolytic streptococcal pharyngitis and tonsillitis-1 g per day in single (q.d.) or divided doses (b.i.d.) for 10 days.

Children

DAILY DOSAGE OF CEFADROXIL FOR ORAL SUSPENSION
Child's Weight
lbs	kg	250 mg/5 mL	500 mg/5 mL
10	4.5	1/2 tsp
20	9.1	1 tsp
30	13.6	1 1/2 tsp
40	18.2	2 tsp	1 tsp
50	22.7	2 1/2 tsp	1 1/4 tsp
60	27.3	3 tsp	1 1/2 tsp
70 & above	31.8+	---	2 tsp

For urinary tract infections, the recommended daily dosage for children is 30 mg/kg/day in divided doses every 12 hours. For pharyngitis, tonsillitis, and impetigo, the recommended daily dosage for children is 30 mg/kg/day in a single dose or in equally divided doses every 12 hours. For other skin and skin structure infections, the recommended daily dosage is 30 mg/kg/day in equally divided doses every 12 hours. In the treatment of beta-hemolytic streptococcal infections, a therapeutic dosage of Cefadroxil should be administered for at least 10 days.

Renal Dosing:
In patients with renal impairment, the dosage of cefadroxil monohydrate should be adjusted according to creatinine clearance rates to prevent drug accumulation. The following schedule is suggested. In adults, the initial dose is 1000 mg of cefadroxil monohydrate and the maintenance dose (based on the creatinine clearance rate [mL/min/1.73 m2]) is 500 mg at the time intervals listed below.

Creatinine Clearances	Dosage Interval
0-10 mL/min	36 hours
10-25 mL/min	24 hours
25-50 mL/min	12 hours

Patients with creatinine clearance rates over 50 mL/min may be treated as if they were patients having normal renal function.

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Microbiology:
In vitro tests demonstrate that the bactericidal action of cephalosporins results from inhibition of cell wall synthesis. Cefazolin has been shown to be active against most strains of the following microorganisms, both in vitro and in clinical infections as described in INDICATIONS AND USAGE.

>Gram-Positive Aerobes
Staphylococcus aureus (including ß-lactamase-producing strains)
Staphylococcus epidermidis
Streptococcus pyogenes, Streptococcus agalactiae, and other strains of streptococci
Streptococcus pneumoniae

Methicillin-resistant staphylococci are uniformly resistant to cefazolin, and many strains of enterococci are resistant.

>Gram-Negative Aerobes
Escherichia coli
Proteus mirabilis

Most strains of indole positive Proteus (Proteus vulgaris), Enterobacter spp., Morganella morganii, Providencia rettgeri, Serratia spp., and Pseudomonas spp. are resistant to cefazolin.
INDICATIONS AND USAGE:
Cefazolin Injection, USP is indicated in the treatment of the following infections due to susceptible organisms:

Respiratory Tract Infections:
Due to S. pneumoniae, S. aureus (including β-lactamase-producing strains), and S. pyogenes.

Injectable benzathine penicillin is considered to be the drug of choice in treatment and prevention of streptococcal infections, including the prophylaxis of rheumatic fever. Cefazolin is effective in the eradication of streptococci from the nasopharynx; however, data establishing the efficacy of cefazolin in the subsequent prevention of rheumatic fever are not available.

Urinary Tract Infections:
Due to E. coli, P. mirabilis.

Skin and Skin Structure Infections:
Due to S. aureus (including β-lactamase-producing strains), S. pyogenes, and other strains of streptococci.

Biliary Tract Infections:
Due to E. coli, various strains of streptococci, P. mirabilis, and S. aureus.

Bone and Joint Infections:
Due to S. aureus.

Genital Infections:
(i.e., prostatitis, epididymitis) due to E. coli, P. mirabilis.

Septicemia:
Due to S. pneumoniae, S. aureus (including β-lactamase-producing strains) P. mirabilis, E. coli.

Endocarditis:
Due to S. aureus (including β-lactamase-producing strains), and S. pyogenes.

Appropriate culture and susceptibility studies should be performed to determine susceptibility of the causative organism to cefazolin.

Perioperative Prophylaxis:
The prophylactic administration of cefazolin preoperatively, intraoperatively, and postoperatively may reduce the incidence of certain postoperative infections in patients undergoing surgical procedures which are classified as contaminated or potentially contaminated (e.g., vaginal hysterectomy, and cholecystectomy in high-risk patients such as those older than 70 years, with acute cholecystitis, obstructive jaundice, or common duct bile stones).

The perioperative use of cefazolin may also be effective in surgical patients in whom infection at the operative site would present a serious risk (e.g., during open-heart surgery and prosthetic arthroplasty).

The prophylactic administration of cefazolin should usually be discontinued within a 24-hour period after the surgical procedure. In surgery where the occurrence of infection may be particularly devastating (e.g., open-heart surgery and prosthetic arthroplasty), the prophylactic administration of cefazolin may be continued for 3 to 5 days following the completion of surgery.

If there are signs of infection, specimens for cultures should be obtained for the identification of the causative organism so that appropriate therapy may be instituted.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of cefazolin and other antibacterial drugs, cefazolin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

DOSAGE AND ADMINISTRATION:
Usual Adult Dosage:

Type of Infection	Dose	Frequency
Moderate to severe infections	500 mg to 1 gram	every 6 to 8 hrs.
Mild infections caused by susceptible gram-positive cocci	250 mg to 500 mg	every 8 hours
Acute, uncomplicated urinary tract infections	1 gram	every 12 hours
Pneumococcal pneumonia	500 mg	every 12 hours
Severe, life-threatening infections (e.g., endocarditis, septicemia)*	1 gram to 1.5 grams	every 6 hours

*In rare instances, doses of up to 12 grams of Cefazolin Injection per day have been used.

Perioperative Prophylactic Use
To prevent postoperative infection in contaminated or potentially contaminated surgery, recommended doses are:
1. 1 gram IV administered one-half hour to 1 hour prior to start of surgery.
2. For lengthy operative procedures (e.g., 2 hours or more), 500 mg to 1 gram IV during surgery (administration modified depending on the duration of the operative procedure).
3. 500 mg to 1 gram IV every 6 to 8 hours for 24 hours postoperatively.

It is important that (1) the preoperative dose be given just (1/2 to 1 hour) prior to start of surgery so that adequate antibiotic levels are present in the serum and tissues at the time of initial surgical incision; and (2) cefazolin be administered, if necessary, at appropriate intervals during surgery to provide sufficient levels of the antibiotic at the anticipated moments of greatest exposure to infective organisms.

In surgery where the occurrence of infection may be particularly devastating (e.g., open-heart surgery and prosthetic arthroplasty), the prophylactic administration of cefazolin may be continued for 3 to 5 days following the completion of surgery.

Renal Dosing: ------------------------
Cefazolin Injection may be used in patients with reduced renal function with the following dosage adjustments: Patients with a creatinine clearance of 55 mL/min. or greater or a serum creatinine of 1.5 mg % or less can be given full doses. Patients with creatinine clearance rates of 35 to 54 mL/min. or serum creatinine of 1.6 to 3.0 mg % can also be given full doses but dosage should be restricted to at least 8 hour intervals.

Patients with creatinine clearance rates of 11 to 34 mL/min. or serum creatinine of 3.1 to 4.5 mg % should be given one-half the usual dose every 12 hours.

Patients with creatinine clearance rates of 10 mL/min. or less or serum creatinine of 4.6 mg % or greater should be given ½ the usual dose every 18 to 24 hours.

All reduced dosage recommendations apply after an initial loading dose appropriate to the severity of the infection.

SOURCE:
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Microbiology:
Microbiology: In vitro tests demonstrate that the cephalosporins are bactericidal because of their inhibition of cell-wall synthesis. Cephradine is active against the following organisms in vitro:

Group A beta-hemolytic streptococci
Staphylococci, including coagulase-positive, coagulase-negative, and penicillinase-producing strains
Streptococcus pneumoniae (formerly Diplococcus pneumoniae)

Escherichia coli
Proteus mirabilis
Klebsiella species
Hemophilus influenzae

Cephradine is not active against most strains of Enterobacter species, P. morganii, and P. vulgaris. It has no activity against Pseudomonas or Herellea species. When tested by in vitro methods, staphylococci exhibit cross-resistance between cephradine and methicillin-type antibiotics.

Note-Most strains of enterococci (Streptococcus faecalis) are resistant to cephradine.
INDICATIONS AND USAGE:
Velosef (Cephradine) Capsules and Velosef for Oral Suspension are indicated in the treatment of the following infections when caused by susceptible strains of the designated microorganisms:

RESPIRATORY TRACT INFECTIONS (e.g., tonsillitis, pharyngitis, and lobar pneumonia) caused by group A beta-hemolytic streptococci and S. pneumoniae (formerly D. pneumonia).

(Penicillin is the usual drug of choice in the treatment and prevention of streptococcal infections, including the prophylaxis of rheumatic fever. Velosef is generally effective in the eradication of streptococci from the nasopharynx; substantial data establishing the efficacy of Velosef in the subsequent prevention of rheumatic fever are not available at present.)

OTITIS MEDIA caused by group A beta-hemolytic streptococci, S. pneumoniae (formerly D. pneumoniae), H. influenzae, and staphylococci.

SKIN AND SKIN STRUCTURE INFECTIONS caused by staphylococci (penicillin-susceptible and penicillin-resistant) and beta-hemolytic streptococci.

URINARY TRACT INFECTIONS, including prostatitis, caused by E. coli, P. mirabilis, Klebsiella species, and enterococci (S. faecalis). The high concentrations of cephradine achievable in the urinary tract will be effective against many strains of enterococci for which disc susceptibility studies indicate relative resistance. It is to be noted that among beta-lactam antibiotics, ampicillin is the drug of choice for enterococcal urinary tract (S. faecalis) infection.

Note-Culture and susceptibility tests should be initiated prior to and during therapy.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Velosef and other antibacterial drugs, Velosef should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Following clinical improvement achieved with parenteral therapy, oral cephradine may be utilized for continuation of treatment of persistent or severe conditions where prolonged therapy is indicated.

DOSAGE AND ADMINISTRATION:
Velosef (Cephradine) may be given without regard to meals.

Adults: For respiratory tract infections (other than lobar pneumonia) and skin and skin structure infections, the usual dose is 250 mg every 6 hours or 500 mg every 12 hours.

For lobar pneumonia, the usual dose is 500 mg every 6 hours or 1 g every 12 hours.

For uncomplicated urinary tract infections, the usual dose is 500 mg every 12 hours. In more serious urinary tract infections, including prostatitis, 500 mg every 6 hours or 1 g every 12 hours may be administered.

Larger doses (up to 1 g every 6 hours) may be given for severe or chronic infections.

Children: No adequate information is available on the efficacy of b.i.d. regimens in children under nine months of age. The usual dose in children over nine months of age is 25 to 50 mg/kg/day administered in equally divided doses every 6 or 12 hours. For otitis media due to H. influenzae, doses are from 75 to 100 mg/kg/day administered in equally divided doses every 6 or 12 hours, but should not exceed 4 g per day. Dosage for children should not exceed dosage recommended for adults.

All patients, regardless of age and weight: Larger doses (up to 1 g q.i.d.) may be given for severe or chronic infections.

As with antibiotic therapy in general, treatment should be continued for a minimum of 48 to 72 hours after the patient becomes asymptomatic or evidence of bacterial eradication has been obtained. In infections caused by group A beta-hemolytic streptococci, a minimum of 10 days of treatment is recommended to guard against the risk of rheumatic fever or glomerulonephritis. In the treatment of chronic urinary tract infection, frequent bacteriologic and clinical appraisal is necessary during therapy and may be necessary for several months afterwards. Persistent infections may require treatment for several weeks. Prolonged intensive therapy is recommended for prostatitis. Doses smaller than those indicated are not recommended.

Renal Dosing:
Not on Dialysis: The following initial dosage schedule is suggested as a guideline based on creatinine clearance. Further modification in the dosage schedule may be required because of individual variations in absorption.

Creatine Clearance	Dose	Time Interval
> 20 mL/min	500 mg	6 hours
5-20 mL/min	250 mg	6 hours
< 50 mL/min	250 mg	12 hours

On Chronic, Intermittent Hemodialysis:
250 mg Start
250 mg at 12 hours
250 mg 36-48 hours (after start)

Children may require dosage modification proportional to their weight and severity of infection.

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Microbiology:
In vitro tests demonstrate that the cephalosporins are bactericidal because of their inhibition of cell-wall synthesis. Cephalexin has been shown to be active against most strains of the following microorganisms both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section.

>Aerobes, Gram-positive:
Staphylococcus aureus (including penicillinase-producing strains)
Streptococcus pneumoniae (penicillin-susceptible strains)
Streptococcus pyogenes

>Aerobes, Gram-negative:
Escherichia coli
Haemophilus influenzae
Klebsiella pneumoniae
Moraxella (Branhamella) catarrhalis
Proteus mirabilis

Note- Methicillin-resistant staphylococci and most strains of enterococci (Enterococcus faecalis [formerly Streptococcus faecalis]) are resistant to cephalosporins, including cephalexin. It is not active against most strains of Enterobacter spp., Morganella morganii, and Proteus vulgaris. It has no activity against Pseudomonas spp. or Acinetobacter calcoaceticus. Penicillin-resistant Streptococcus pneumoniae is usually cross-resistant to beta-lactam antibiotics.

INDICATIONS AND USAGE:
Keflex is indicated for the treatment of the following infections when caused by susceptible strains of the designated microorganisms:

Respiratory tract infections caused by Streptococcus pneumoniae and Streptococcus pyogenes (Penicillin is the usual drug of choice in the treatment and prevention of streptococcal infections, including the prophylaxis of rheumatic fever. Keflex is generally effective in the eradication of streptococci from the nasopharynx; however, substantial data establishing the efficacy of Keflex in the subsequent prevention of rheumatic fever are not available at present.)

Otitis media due to Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Streptococcus pyogenes, and Moraxella catarrhalis

Skin and skin structure infections caused by Staphylococcus aureus and/or Streptococcus pyogenes

Bone infections caused by Staphylococcus aureus and/or Proteus mirabilis

Genitourinary tract infections, including acute prostatitis, caused by Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae

Note- Culture and susceptibility tests should be initiated prior to and during therapy. Renal function studies should be performed when indicated.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Keflex and other antibacterial drugs, Keflex should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

DOSAGE AND ADMINISTRATION:
Keflex is administered orally.

Adults-- The adult dosage ranges from 1 to 4 g daily in divided doses. The 333 mg and 750 mg strengths should be administered such that the daily dose is within 1 to 4 grams per day. The usual adult dose is 250 mg every 6 hours. For the following infections, a dosage of 500 mg may be administered every 12 hours: streptococcal pharyngitis, skin and skin structure infections, and uncomplicated cystitis in patients over 15 years of age. Cystitis therapy should be continued for 7 to 14 days. For more severe infections or those caused by less susceptible organisms, larger doses may be needed. If daily doses of Keflex greater than 4 g are required, parenteral cephalosporins, in appropriate doses, should be considered.

Pediatric Patients-- The usual recommended daily dosage for pediatric patients is 25 to 50 mg/kg in divided doses. For streptococcal pharyngitis in patients over 1 year of age and for skin and skin structure infections, the total daily dose may be divided and administered every 12 hours.

In severe infections, the dosage may be doubled.

In the therapy of otitis media, clinical studies have shown that a dosage of 75 to 100 mg/kg/day in 4 divided doses is required.

In the treatment of β-hemolytic streptococcal infections, a therapeutic dosage of Keflex should be administered for at least 10 days.

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