Keflin Side Effects

Generic Name: cephalothin

Note: This page contains information about the side effects of cephalothin. Some of the dosage forms included on this document may not apply to the brand name Keflin.

Not all side effects for Keflin may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Applies to cephalothin: injectable powder for injection, intravenous solution


Hypersensitivity reactions occur in up to 15% of patients with a history of penicillin allergy. Manifestations may include urticarial or maculopapular rash, bronchospasm, and drug fever. Anaphylaxis, including severe hypotension and cardiac arrest, is reported.

Rare cases of renal insufficiency associated with cephalothin may be hypersensitivity-mediated since fever, eosinophilia, and rash are often also present.

A case of occupational contact dermatitis due to cephalosporin allergy has been reported in a nurse who prepared cephalosporin solutions for administration to patients. The dermatitis resolved after the nurse stopped preparing the solutions.


Predisposing risk factors for nephrotoxicity include preexisting renal insufficiency, concomitant use of other potentially nephrotoxic drugs, and dehydration. Renal biopsy results in patients with suspected cephalothin-induced renal insufficiency have shown tubulo-interstitial nephritis. The mechanism may be hypersensitivity-mediated.

Renal side effects including renal insufficiency is rarely reported during therapy with most cephalosporins. Nephrotoxicity appears to be slightly more likely during cephalothin therapy, however. Risk factors include concomitant aminoglycoside therapy, preexisting renal insufficiency, elevated serum aminoglycoside levels, and high dose cephalothin therapy. Cephalothin may worsen renal function in patients with renal insufficiency. Frequent monitoring of the serum creatinine, maintenance of intravascular volume, and avoidance of potentially nephrotoxic agents during cephalothin therapy is recommended.


Hematologic side effects include thrombocytopenia, hemolytic anemia, and rare cases of pancytopenia.

One case of reversible aplastic anemia associated with cephalothin has been reported.


Gastrointestinal side effects are unusual. Rare cases of pseudomembranous colitis associated with cephalothin (the active ingredient contained in Keflin) are reported.


Hepatic side effects are rare. Increases in serum transaminases associated with cephalothin (the active ingredient contained in Keflin) are reported.

Nervous system

In rare cases of suspected cephalothin-associated confusion, cerebrospinal fluid has been sterile, but has, in rare cases shown high levels of drug.

Nervous system side effects are rare, and include reports of delirium and confusion.


The incidence of phlebitis may be reduced by frequent intravenous site care and the addition of heparin 500 units and hydrocortisone 10 mg to each liter of intravenous cephalothin (the active ingredient contained in Keflin)

Intravenous site phlebitis has been reported in up to 55% of patients.

Women may experience an increased incidence of vaginal yeast infections while receiving cephalothin.

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