Infectious Disease Compendium

Ciprofloxacin (Cipro®)


CrCl Formula

CrCl > 80: 250 - 750 mg q 12 h po or 200 - 400 mg q 12 h iv.

CrCl 80-50: 250- 750 mg q 12 h po or 200 - 400 mg q 12 h iv.

CrCl 50-10: 250 - 500 mg q 12 h po or 200 - 400 mg q 12-24 h iv

CrCl < 10: 250 - 500 mg q 18 h po or 200 - 400 mg q 18 - 24 h iv.

Hemodialysis: 250 - 500 mg q 24 h.

Peritoneal dialysis: 250 - 500 mg q 24 h.

Obesity dosing

Important side effects

Like all quinolones, it can affect the QT interval.

All variety of neuropsychiatric side effects; not recommended for children, adolescents, and pregnant or lactating women due to arthropathy.

Achilles tendon rupture.

Diplopia (PubMed).

Maybe retinal detachment (PubMed). Or not (PubMed). Probably for rhegmatogenous retinal detachment (PubMed).

Arrhythmias: "Gatifloxacin use was associated with the highest rate (RR = 7.38; 95% CI, 2.30-23.70); moxifloxacin and ciprofloxacin were also associated with elevated rates of serious arrhythmia (RR = 3.30; 95% CI, 1.47-7.37 and RR = 2.15; 95% CI, 1.34-3.46, respectively)" (PubMed). Not so much with levofloxacin.

It can double the risk of acute kidney injury (PubMed).

Increases risk of AAA rupture, but not in every study (PubMed).

It can worsen myasthenia gravis.

Selects for C. difficile and MRSA.

Important drug interactions

Ca, Mg, Fe, and Sulcralfate will markedly inhibit po absorption. Antidiabetic agents, azlocillin, calcium, corticosteroids, cyclosporine, didanosine, duloxetine, dutasteride, fosphenytoin, indomethacin, iron, methotrexate, metoprolol, olanzapine, phenytoin, probenecid, propranolol, rifapentine, ropinirole, ropivacaine, sucralfate, teicoplanin, theophylline, tizanidine, warfarin, zinc.

Rants and Screeds

Its use is discouraged (FDA Warning). While a great antibiotic, it's many toxicities make it a second-line agent if you have other option.


Do not give it iv if the patient can take po. Excellent absorption.

Treatment of choice

The dread Pseudomonas. Not at bad as the Dread Pirate Roberts.

Use for

Almost anything gram-negative. GI decontamination, Anthrax - post-exposure prophylaxis and treatment, Arthritis, bone marrow transplantation - prophylaxis, Bronchitis, Cat scratch fever, Cellulitis, Chancroid, Cholangitis, Cholecystitis, Cholera, Conjunctivitis, Cystic fibrosis, Endocarditis, Enterobacter, Gonorrhea, Helicobacter pylori - triple therapy, infectious Diarrhea, Intraabdominal infections, Klebsiella infections, Mediterranean Spotted Fever, meningitis - multidrug-resistant, Mycobacterium non-tuberculous and tuberculosis, Meningococcus, Neutropenic fever, nongonococcal Urethritis, Osteomyelitis, Otitis externa, Otitis media - chronic, Peritonitis, Plague, Pneumonia, Proteus, Providencia, Pseudomonas, rhinoscleroma, Rickettsia infections, Salmonella carriers and infections, Serratia, Shigella Sinusitis, Staphylococcus aureus (but don't do it), Stenotrophomonas, Streptococcus pneumoniae (but don't do it), chronic bacterial Prostatitis, Tularemia, Typhoid fever, UTI, Yersinia enterocolitica infections.

Don't use for

Anything round and purple, say Streptococci or Staphylococcus.



Curious Cases

Relevant links to my Medscape blog

My Powers in Action

No other options? I think not.

Last Update: 09/16/20.