FLUOROQUINOLONES

Dose adjustment is not required for Trovafloxacin, Moxifloxacin, Pefloxacin and Nalidixic acid for patient with decreased creatinine clearence. Trovafloxacin will cause liver damage and increase in liver enzymes. So it is contraindicated in patients with active liver disease.

Ans. is ‘b’ i.e., DNA gyrase

o Fluoroquinolones (including ciprofloxacin) inhibit DNA gyrase and topoisomerase IV. For gram negative bacteria, the primary target is DNA gyrase, while topoisomerase IV is inhibited in gram positive bacteria.

Ans. is ‘d’ i.e., Sparfloxacin

o Highest incidence of phototoxicity is seen with lomefloxacin (most common) and sparfloxacin, followed by pefloxacin.

Ans. is ‘b’ i.e., Gatifloxacin

o Gatifloxacin has recently been banned in India, due to risk of severe hyperglycemia in elderly.

Note: Following FQs have been withdrawn from the market because of their rare but potentially fatal side effects (Goodman & Gilman 1 Pie 1119)

o Temafloxacin                             Immune hemolytic anemia                         o Grepafloxacin           Cardiotoxicity

o Trovafloxacin                         Hepatotoxicity                                            o Clinafloxacin             Phototoxicity

Ans. is ‘b’ i.e., Trovofloxacin

• Fluoroquinolones that are excreted primarily by non renal mechanism and for which adjustment is not needed in renal pathology include :

1. Nalidixic acid                      3. Trovafloxacin                  5. Moxifloxacin
2. Grepofloxacin                     4. Pefloxacin

• Fluroquinolones that are primarily excreted by renal mechanisms and for which dose adjustment is needed include:

1. Ciprofloxacin                      3. Gatifloxacin                              5. Lomefloxacilin                7. Ofloxacin

2. Cinafloxacin                       4. Levofloxacilin                            6. Norfloxacin

• Sparfloxacin has 50% renal and 50% faecal route of excretion and hence dose adjustment may be required in renal pathology.

Ans. is ‘d’ i.e., More active at acidic pH

Ciprofloxacin is the most potent first generation FQ.

Ciprofloxacin inhibit DNA gyrase and is contraindicated in pregnancy.

It is less active at acidic pH.

Ans. is ‘b’ i.e., It increases the toxicity of theophylline

Important interactions of FOs

o Plasma concentration of theophylline, caffine and warfarin are increased by ciprofloxacin, norfloxacin and pefloxacin.

o NSAIDSs enhance CNS toxicity of FQS.

o Antacids, sucralfate and iron salts reduce absorption of FQs.

Ans. is ‘c’ i.e., Nortloxacin