**6.1.3.1 Allergic reactions**

Penicillin allergy can be diagnosed by taking a skin test. Acute allergic reactions can be such delayed reactions as anaphylaxis, angioneurotic edema and urticarial; and also be fever, eosinophilia, hemolytic anemia, serum disease, urticarial and maculopapular rash. The presence of rash is not indication to cease drug use (Eroğlu, 2002).

#### **6.1.3.2 Dose-related effects**

High doses can cause CNS toxicity, hypopotassemia and coagulation impairments (Apak, 1996; Eroğlu, 2002).

#### **6.1.4 Cephalosporins**

Their mechanisms of action resemble to penicillin. They are grouped in four generations. As the generation increases the activity against gram (-) also increases. The ones aside from cefuroxime and third-generation are not able to penetrate CNS. They cannot be used in bacterial meningitis treatment. Cephalosporins are commonly used because of their clinical utilities in the treatment of common infections (Rang et al, 1998; Zeph, 2002).

While maculopapular rash, drug-related fever and positive Coomb's test are the major side effects such reactions and anaphylaxis as urticarial and serum diseases are rarely seen (Rang et al, 1998; Zeph, 2002).

Cephalosporins cause allergic reactions in patients allergic to Penicillin. With the use of cephalosporin side effects are observed in 10% of the patients allergic to Penicillin (Puchner & Zacharisen, 2002).

#### **6.1.4.1 First-generation cephalosporins**

They are active against gram (+) cocci including staphylococcus aureus, and such gram (-) organisms as *E. coli* and *Klebsiella*. They are inactive against enterococci and H. influenzae. First-class cephalosporins cannot cross the blood-brain barrier and so are not effective in the treatment of central nervous system infections (Apak, 1996; Behrman & Kliegman, 2001; Dökmeci, 2000; Eroğlu, 2002).
