and third generation agents. In general, progression from first to third generation
reveals greater gram-negative spectrum, loss of efficacy against gram-positive
organisms, greater efficacy against resistant organisms, and increased costs.
a. Indications. These agents are most useful in:
(1) The treatment of serious gram-negative bacterial infections due to
susceptible organisms that do not respond to agents of first choice.
(2) The treatment of urinary tract or respiratory tract infections due to
(3) The treatment of infections with penicillinase-producing staphylococci.
In addition, a cephalosporin may be occasionally used as a substitute in known
penicillin-allergic clients. CAUTION: Some cross-hypersensitivity exists.
b. Usual Dosage.
(1) Cephalothin (Keflin). Cephalothin, a first generation agent, is for
parenteral use only; it may be given intravenously or by deep intramuscular injection.
The usual adult dose range is 500 mg to 1 gram every 4 to 6 hours. In life-threatening
infections, doses up to 2 grams every 4 hours may be required.
(2) Cephapirin (Cefadyl). Cephapirin, a first generation agent, is for
parenteral use only and has a spectrum of activity similar to cephalothin.
(3) Cephalexin (Keflex). Cephalexin, another first generation agent, is for
oral administration only; the usual adult dose is 250 mg qid, with a maximum of 4 grams
daily for more severe infections. The daily dose for children is 25 to 50 mg per kg of
body weight, divided into four doses.
(4) Cefoxitin (Mefoxin). Cefoxitin, a second generation agent, is for
parenteral use only. It has greater activity against gram negative organisms than first
(5) Cefaclor (Ceclor). Cefaclor is a second generation agent for oral use
only. It is employed primarily for otitis media and respiratory tract infections.
(6) Ceftriaxone (Rocephin). Ceftriaxone, a third generation cephalosporin,
is for parenteral use only. It is administered once daily either IM or IV.
c. Cautions and Warnings.
(1) All cephalosporins are contraindicated in clients who have shown
hypersensitivity to any one cephalosporin.