ANTIBACTERIAL ACTIVITY Wide spectrum of activity vs aerobic bacteria. Wide spectrum of activity vs aerobic bacteria. Newer 3 rd and 4 th generation FQ’s have very good activity against gram-positive organisms. Newer 3 rd and 4 th generation FQ’s have very good activity against gram-positive organisms. Inactive against most anaerobic bacteria. Inactive against most anaerobic bacteria.

MECHANISM In gram - bacteria, DNA gyrase is the primary target. In gram - bacteria, DNA gyrase is the primary target. In gram + bacteria, topoisomerase IV is the primary target (newer quinolones). In gram + bacteria, topoisomerase IV is the primary target (newer quinolones).

PHARMACOKINETICS Rapidly absorbed from the GI tract. Rapidly absorbed from the GI tract. Widely distributed in body tissues (except CNS). Widely distributed in body tissues (except CNS). Excreted via the kidney both unchanged and as metabolites. Excreted via the kidney both unchanged and as metabolites.

PHARMACOKINETICS Newer FQ’s have longer serum half-lives than ciprofloxacin allowing for once daily dosing. Newer FQ’s have longer serum half-lives than ciprofloxacin allowing for once daily dosing.

THERAPEUTIC USES

Strept. pneumoniae

THERAPEUTIC USES Gastrointestinal infections. Gastrointestinal infections.

CONTRAINDICATIONS Children less than 18 years old and pregnant or nursing women. Children less than 18 years old and pregnant or nursing women.

DRUG INTERACTIONS Quinolones + divalent and trivalent cations Quinolones + divalent and trivalent cations IMPAIRED ABSORPTION OF QUINOLONES

Mechanism of action Therapeutic uses Adverse Effects Ciprofloxacin- Inhibits DNA Gyrase predominantly UTI’s, Bone, joint and soft tissue infections GI, CNS, Photosensitivity Gatifloxacin-Inhibits Topoisomerase IV predominantly Community acquired pneumonia GI, CNS + Phototoxicity and EKG COMPARISON OF 2 ND GEN.VS 3 TH AND 4 TH GEN. FQ’S

MECHANISM OF ACTION Bactericidal. Bactericidal. Inhibit DNA gyrase (topoisomerase II). Inhibit DNA gyrase (topoisomerase II). Inhibition of topoisomerase IV (newer FQ’s). Inhibition of topoisomerase IV (newer FQ’s).

MECHANISM DNA gyrase is the primary target. It is responsible for the continuous introduction of negative supercoils into DNA. This is an ATP-dependent enzyme requiring that both strands of the DNA be cut to permit passage of a segment of DNA thru a break, which is then resealed. DNA gyrase is the primary target. It is responsible for the continuous introduction of negative supercoils into DNA. This is an ATP-dependent enzyme requiring that both strands of the DNA be cut to permit passage of a segment of DNA thru a break, which is then resealed.

ADVERSE EFFECTS GI effects are common (mild nausea, upper GI discomfort). GI effects are common (mild nausea, upper GI discomfort).

ADVERSE EFFECTS CNS effects such as headache, restlessness, and dizziness. High doses may produce convulsions. CNS effects such as headache, restlessness, and dizziness. High doses may produce convulsions.

ADVERSE EFFECTS Hypersensitivity reactions---rashes including photosensitivity reactions. Hypersensitivity reactions---rashes including photosensitivity reactions.

ADVERSE EFFECTS Prolongation of the QT interval with possible serious arrhythmias. Prolongation of the QT interval with possible serious arrhythmias. Hypoglycemia and hyperglycemia. Hypoglycemia and hyperglycemia.

His/Purk. Ventricle P R Q S T Prolong QT Interval