BMA Concise Guide to Medicine & Drugs


Brand names Ciloxan, Ciproxin

Used in the following combined preparations None


Drug group Antibacterial drug

Overdose danger rating Medium

Dependence rating Low

Prescription needed Yes

Available as generic Yes


Ciprofloxacin, a quinolone antibacterial, is used to treat several types of bacteria resistant to other commonly used antibiotics. It is especially useful for chest, intestine, and urinary tract infections. When taken by mouth, ciprofloxacin is well absorbed by the body and works quickly and effectively. In more severe systemic bacterial infections, however, it may be necessary to administer the drug by injection.

The most common side effect of ciprofloxacin is gastrointestinal disturbance. Occasionally it may cause tendon inflammation and damage (see advice for levofloxacin).


Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, liquid, injection.

Frequency and timing of doses 2 x daily with plenty of fluids.

Adult dosage range 500mg–1.5g daily (tablets); 400mg–1.2g daily (injection).

Onset of effect The drug begins to work within a few hours, although full beneficial effect may not be felt for several days.

Duration of action About 12 hours.

Diet advice Do not become dehydrated. Avoid dairy products; they may reduce the drug’s absorption.

Storage Keep in original container at room temperature out of the reach of children. The injection must be protected from light.

Missed dose Take as soon as you remember, and take your next dose as usual.

Stopping the drug Take the full course. Even if you feel better the original infection may still be present, and symptoms may recur if treatment is stopped too soon.

Exceeding the dose An occasional unintentional extra dose is unlikely to cause problems. Large overdoses may cause kidney problems, mental disturbance and seizures. Notify your doctor.


Most side effects are rare, except when very high doses are given. Nausea, vomiting, abdominal pain, diarrhoea, rash, and itching are the most common adverse effects. Others include dizziness, headache, sleep disturbances, sensitivity to light, jaundice, and confusion. Consult your doctor if you develop a rash or itching, sensitivity to light, jaundice, or confusion, or if any of the other symptoms are severe. If you have seizures or develop painful joints or tendons, stop taking the drug and contact your doctor immediately. With joint or tendon pain, you should also rest the affected limbs until the symptoms subside.


General note Many drugs interact with ciprofloxacin, including anticoagulants, oral antidiabetics, phenytoin, theophylline/aminophylline, non-steroidal anti-inflammatory drugs, tricyclic antidepressants, clarithromycin, erythromycin, antipsychotics, and tinzanidine. Do not take any over-the-counter or prescription medications without consulting your doctor or pharmacist.

Oral iron preparations and antacids containing magnesium or aluminium hydroxide interfere with absorption of ciprofloxacin. Do not take antacids within 2 hours of taking ciprofloxacin tablets.


Be sure to tell your doctor if:

· You have long-term liver or kidney problems.

· You have had epileptic seizures.

· You have glucose-6-phosphate dehydrogenase (G6PD) deficiency.

· You have myasthenia gravis.

· You are taking other medicines.

Pregnancy Safety in pregnancy not established. Discuss with your doctor.

Breast-feeding The drug passes into the breast milk and may affect the baby adversely. Discuss with your doctor.

Infants and children Not usually recommended.

Over 60 Reduced dose may be necessary.

Driving and hazardous work Avoid such activities until you have learned how ciprofloxacin affects you because the drug can cause dizziness and confusion.

Alcohol Avoid. Alcohol may increase the sedative effects of this drug.

Sunlight and sunbeds Avoid direct exposure to sunlight or sunlamps; increased risk of a photosensitivity reaction.


Ciprofloxacin is not usually prescribed for long-term use.