Cipro (Ciprofloxacin): Uses, Dosage & Safety Information

What is Cipro?

Ciprofloxacin is a prescription fluoroquinolone antibacterial supplied as tablets and as an oral suspension. It treats skin, bone, abdominal and urinary infections, typhoid fever, and post-exposure anthrax and plague. Cipro remains an approved Bayer brand alongside generics.² It is listed under antibiotics on iMedix.

Its indication list is unusually wide, and includes two that most antibiotics never carry: post-exposure inhalational anthrax and plague, in adults and children. Those sit alongside ordinary infections of skin, bone, abdomen and urinary tract.

Breadth is not the same as first choice. Because the boxed warning describes reactions that may not reverse, the label restricts several indications to patients who have no alternative treatment options.

How to Take Cipro

How much and for how long

Adult doses are usually 250 mg to 750 mg every 12 hours, set by the infection: for example 500 mg to 750 mg for 7 to 14 days in skin infections, 4 to 8 weeks in bone and joint infections, 250 mg every 12 hours for 3 days in uncomplicated cystitis, and 500 mg every 12 hours for 60 days after anthrax exposure. Children are dosed by weight only for the indications labelled for them.¹

Separate it from antacids, iron, zinc, calcium and dairy by several hours. These bind ciprofloxacin in the gut and can reduce absorption enough to make treatment fail.

Drink enough fluid. Adequate hydration reduces the risk of crystals forming in the urine.

Stop and call at the first tendon pain — typically Achilles, but any tendon — and rest that limb. The same applies to new numbness, tingling, burning, confusion or agitation.

Avoid strong sun. Ciprofloxacin can cause exaggerated sunburn reactions.

What Are the Side Effects of Cipro?

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What is Cipro Used For?

Ciprofloxacin is indicated in adults, and in children where specified, for infections caused by designated susceptible bacteria.

• Skin and skin structure infections
• Bone and joint infections
• Complicated intra-abdominal infections
• Infectious diarrhoea
• Typhoid fever — enteric fever
• Uncomplicated cervical and urethral gonorrhoea
• Inhalational anthrax, post-exposure, in adults and children
• Plague, in adults and children

Where the label pulls back. For acute sinusitis, acute exacerbation of chronic bronchitis and uncomplicated urinary tract infection, ciprofloxacin is reserved for patients who have no alternative treatment options, because the risk of disabling reactions outweighs the benefit in conditions that often resolve on their own.

The anthrax and plague indications exist for a different reason: few oral antibacterials work against those organisms, and the calculus of risk changes completely when the alternative is an untreated lethal infection.

Cipro remains an approved Bayer brand, with one tablet application listed as discontinued and others active, and generic ciprofloxacin widely marketed.²

The concern with this drug is not availability but positioning. It is convenient, oral, broad and familiar, which makes it easy to reach for in exactly the conditions where its label says to hold back. The boxed warning describes harm that can be permanent, and the reserved indications exist to keep that risk out of infections that would settle on their own.

Critical Warnings for Cipro Use

The boxed warning is about reactions that may not reverse

Tendinitis and tendon rupture, peripheral neuropathy and central nervous system effects have occurred together in the same patients, and the label describes them as disabling and potentially irreversible. The instruction is not to reduce the dose but to discontinue ciprofloxacin immediately and avoid fluoroquinolones thereafter.

Tendon injury

Risk is increased in patients over 60, in those taking corticosteroids, and in kidney, heart or lung transplant recipients. Rupture has occurred during treatment and months after it ended, most often in the Achilles tendon.

Myasthenia gravis

Fluoroquinolones may exacerbate muscle weakness. The label directs avoiding ciprofloxacin in patients with a known history of the condition.

Aortic aneurysm and dissection

Reported with fluoroquinolone use. The drug is used in patients with a known aneurysm or risk factors only when no alternative is available.

Reserved indications

For acute sinusitis, acute exacerbation of chronic bronchitis and uncomplicated urinary tract infection, ciprofloxacin is reserved for patients with no alternative treatment options. These conditions frequently resolve without antibacterials, and the label weighs that against a warning about permanent harm.

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Quinolone hypersensitivity

Contraindicated in a history of hypersensitivity to ciprofloxacin, any other quinolone or any product component.¹

Tizanidine

Contraindicated with tizanidine because of potentiated low blood pressure and sedation.¹

See Interactions.

Dosage

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What Does Cipro Interact With?

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Evidence scope

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What has been reported to the FDA

As of the FAERS data cut of 30 July 2026, the FDA Adverse Event Reporting System held 21,849 reports naming Cipro, of which 14,461 were classed as serious — 66% of the total.³

Who was this medicine studied in?

The licensed indications cover adults from 18 years, with specific paediatric indications for anthrax post-exposure, plague and complicated urinary tract infection.¹ The anthrax and plague indications rest partly on animal efficacy data, since human trials in those infections are not feasible.²⁵

Who this is and is not appropriate for

It is not appropriate for anyone hypersensitive to any quinolone, nor for anyone taking tizanidine. It is avoided in myasthenia gravis, and used with particular caution over 60, on corticosteroids, or with an existing aortic aneurysm.¹

It suits serious infection where the organism and the site justify a fluoroquinolone — bone and joint infection, complicated intra-abdominal infection, typhoid, anthrax exposure. It does not suit a sinus infection that would clear on its own.

Where to report and verify

References

1. FDA Prescribing Information, Cipro (ciprofloxacin hydrochloride) tablets and oral suspension (Bayer, NDA 019537, NDA 020780) — Boxed Warning, Indications and Usage 1, Dosage and Administration 2, Dosage Forms and Strengths 3, Contraindications 4, Warnings and Precautions 5, Adverse Reactions 6, Drug Interactions 7, Use in Specific Populations 8, Overdosage 10
   Label effective 2026-03-02 · Accessed 2026-09-28
   Used for: indications, dosing and renal table, contraindications, boxed and other warnings, interactions.
   dailymed.nlm.nih.gov — DailyMed
2. Drugs@FDA — NDA 019537 (Cipro tablets) and NDA 020780 (Cipro oral suspension)
   Records · Accessed 2026-09-28
   Used for: brand status and marketing.
   accessdata.fda.gov — Drugs@FDA
3. openFDA — FDA Adverse Event Reporting System, drug event query for Cipro
   Data cut 2026-07-30 · Accessed 2026-09-28
   Used for: report totals, serious counts and most reported terms.
   open.fda.gov — openFDA
4. FDA Orange Book — ciprofloxacin
   Current edition · Accessed 2026-09-28
   Used for: reference-standard and generic availability.
   accessdata.fda.gov — Orange Book
5. FDA — Drug Trials Snapshots programme scope
   Programme current · Accessed 2026-09-28
   Used for: confirmation that Snapshots cover novel drugs approved from 2015.
   fda.gov — Drug Trials Snapshots

Review cycle. Clinical review completed 28 September 2026. Next review due by 28 September 2027, or earlier if the labelling is revised.

Disclaimer: The information on this site is provided for informational purposes only and is not medical advice. It does not replace professional medical consultation, diagnosis, or treatment. Do not self-medicate based on the information presented on this site. Always consult with a doctor or other qualified healthcare professional before making any decisions about your health.