Quinolones

Question 1

What is it indicated for?

Answer 1

Systemically administered quinolones are best reserved for severe bacterial infections in which other treatment options are limited

UTI
Severe gastroenteritis
Lower respiratory tract infections, including exacerbation of COPD and pneumonia

Question 2

What is the spectrum of activity?

Answer 2

Relatively broad spectrum of activity, particularly against gram-negative bacteria

Question 3

How do they work?

Answer 3

Quinolones kill bacteria (bactericidal effect) by inhibiting DNA synthesis.

Question 4

What side effects occur with these drugs?

Answer 4

GI upset
Immediate and delayed-type hypersensitivity reactions
C.difficile infections
Neurological- convulsions, peripheral neuropathy
Musculoskeletal (tendon damage and rupture)
Cardiovascular- QT interval prolongation, valvular reurgitation and aortic aneursym/dissection

Question 5

What are the warnings for these drugs?

Answer 5

Use in caution in pregnancy and in children and young adults who are growing, adults >60 years (risk of tendon damage), renal impairment and people with risk of neurological or cardiovascular morbidity

Question 6

What interactions occur with other drugs and this class?

Answer 6

Drugs containing divalent cations (calcium, iron, antacids) reduce absorption and efficacy of quinolones

Ciprofloxacin inhibits certain CYP enzymes increasing toxicity of some drugs notably theophylline

Co-prescription of NSAIDs increases the risk of seizures, prednisolone increases the risk of tendon rupture

Caution when used with drugs that prolong the QT interval

Question 7

What are the names of some drugs in this class?

Answer 7

ciprofloxacin, levofloxacin, ofloxacin, moxifloxacin