CEFADROXIL

By | 2010-07-08

For general information on the cephalosporins including adverse effects, contraindications, over-dosage, drug interactions, and monitoring parameters, refer to the monograph: Cephalosporins, General Information.

Chemistry

A semisynthetic cephalosporin antibiotic, cefadroxil occurs as a white to yellowish-white, crystalline powder that is soluble in water and slightly soluble in alcohol. The commercially available product is available as the monohydrate.

Storage – Stability – Compatibility

Cefadroxil tablets, capsules and powder for oral suspension should be stored at room temperature (15-30°C) in tight containers. After reconstitution, the oral suspension is stable for 14 days when kept refrigerated (2-8°C).

Pharmacology/Spectrum of Activity

A first generation cephalosporin, cefadroxil exhibits activity against the bacteria usually covered by this class. Refer to the monograph: Cephalosporins, General Information for additional information.

Cefadroxil: Uses – Indications

Cefadroxil is approved for oral therapy in treating susceptible infections of the skin, soft tissue, and genitourinary tract in dogs. It has also been used clinically in cats.

Pharmacokinetics (specific)

Cefadroxil is reportedly well absorbed after oral administration to dogs without regard to feeding state. After an oral dose of 22 mg/kg, peak serum levels of approximately 18.6 micrograms/ml occur within 1-2 hours of dosing. Only about 20% of the drug is bound to canine plasma proteins. The drug is excreted into the urine and has a half-life of about 2 hours. Over 50% of a dose can be recovered unchanged in the urine within 24 hours of dosing.

In cats, the serum half-life has been reported as approximately 3 hours.

Oral absorption of cefadroxil in adult horses after oral suspension was administered was characterized as poor and erratic. In a study done in foals, oral bioavailability ranged from 36-99.8% (mean=58.2%); mean elimination half-life was 3.75 hours after oral dosing.

Cefadroxil: Doses

Doses for dogs:

For susceptible infections:

a) 22 mg/kg PO bid. Treat skin and soft tissue infections for at least 3 days, and GU infections for at least 7 days. Treat for at least 48 hours after animal is afebrile and asymptomatic. Reevaluate therapy if no response after 3 days of treatment. Maximum therapy is 30 days. (Package Insert; Cefa-Tabs® — Fort-Dodge).

b) 11-33 mg/kg PO q8h

c) 20 mg/kg PO bid (q12h)

d) 22 mg/kg PO q8-12h; administer with food if GI upset occurs

Doses for cats:

For susceptible infections:

a) 11-33 mg/kg PO q8h

b) 22 mg/kg PO q8-12h; administer with food if GI upset occurs

c) 10 mg/kg PO q12h

d) 20 mg/kg PO ql2-24h

Dosage Forms – Preparations – FDA Approval Status – Withholding Times

Veterinary-Approved Products:

Cefadroxil Oral Tablets 50 mg, 100 mg, 200 mg, 1 gram; Cefa-Tabs® (Fort-Dodge); (Rx) Approved for use in dogs and cats

Cefadroxil Powder for Oral Suspension 50 mg/ml in 15 ml and 50 ml bts;Cefa-Drops ® (Fort-Dodge) (Rx)

Human-Approved Products:

Cefadroxil Oral Tablets 1 gram; Duri-Cef® (Mead-Johnson); (Rx) generic (Rx)

Cefadroxil Oral Capsules 500 mg; Duri-Cef® (Mead-Johnson); generic (Rx)

Cefadroxil Oral Suspension 125 mg/5 ml, 250 mg/5 ml, 500 mg/5 ml; Duri-Cef® (Mead-Johnson); generic (Rx)