Who should not take cipro (ciprofloxacin)?

Who Should Not Take Ciprofloxacin

Do not take ciprofloxacin if you have a history of severe allergic reactions to fluoroquinolone antibiotics, are currently taking tizanidine, or have experienced tendon disorders related to fluoroquinolone use. 1

Absolute Contraindications

Allergy and Drug Interactions

• Severe hypersensitivity: Patients with prior severe allergic reactions to any fluoroquinolone antibiotic should never receive ciprofloxacin 1
• Concurrent tizanidine use: Ciprofloxacin is absolutely contraindicated with tizanidine (Zanaflex) due to serious, life-threatening drug interactions 1

Relative Contraindications and High-Risk Populations

Elderly Patients (≥65 years)

• The American Geriatrics Society Beers Criteria identifies ciprofloxacin as potentially inappropriate in older adults due to substantially increased risks of tendinitis, tendon rupture, CNS disorders, and dangerous drug interactions 2
• Elderly patients face heightened bleeding risk when ciprofloxacin is combined with warfarin, a common anticoagulant in this population 2
• Risk of theophylline toxicity increases significantly in elderly patients taking both medications 2
• Ciprofloxacin should be avoided when safer alternatives exist; reserve for multidrug-resistant infections with no other options 2

Pediatric Patients (<18 years)

• Ciprofloxacin should not be used as first-line therapy in children under 18 years due to increased risk of musculoskeletal problems including bone, joint, and tendon pain or swelling 1
• Use is restricted to specific serious infections only: complicated urinary tract infections and post-exposure anthrax prophylaxis 1
• The risks versus benefits must be carefully weighed, as fluoroquinolones can cause adverse effects on developing cartilage 3
• When anthrax exposure is confirmed and the strain is penicillin-susceptible, switch to amoxicillin to complete therapy 3

Pregnant and Breastfeeding Women

• Ciprofloxacin is recommended for pregnant women only in life-threatening situations such as anthrax exposure, where disease severity outweighs potential teratogenic risk 3
• The actual teratogenic risk remains unknown due to limited human data 3
• For confirmed penicillin-susceptible anthrax, treatment should be switched to amoxicillin 3
• Ciprofloxacin passes into breast milk; discuss with your provider whether to discontinue breastfeeding or avoid the medication 1

High-Risk Medical Conditions

Musculoskeletal Disorders

• History of tendon problems: Patients with prior tendinitis or tendon disorders should avoid ciprofloxacin 1
• Rheumatoid arthritis or joint disease: These patients face increased risk of tendon complications 1
• Concurrent corticosteroid use: Oral or injectable steroids significantly increase tendon injury risk when combined with ciprofloxacin 1

Neurological Conditions

• Central nervous system disorders: Patients with epilepsy or seizure history have increased risk of CNS effects 1
• Peripheral neuropathy: Those with existing nerve problems should avoid ciprofloxacin due to risk of permanent nerve damage 1
• Concurrent NSAID use increases risk of CNS effects and seizures 1

Cardiac Conditions

• QT prolongation: Patients with personal or family history of irregular heartbeat, especially QT prolongation, should not receive ciprofloxacin 1
• Concurrent antiarrhythmic medications: Combining ciprofloxacin with drugs controlling heart rate or rhythm increases cardiac risk 1

Renal Impairment

• While not an absolute contraindication, patients with kidney dysfunction require dose adjustment 1
• Discuss kidney function with your provider before starting ciprofloxacin 1

Critical Drug Interactions Requiring Avoidance

Beyond tizanidine, exercise extreme caution or avoid ciprofloxacin with:

• Warfarin: Increased bleeding risk 1
• Theophylline: Risk of theophylline toxicity 1
• Glyburide: Altered blood glucose control 1
• Medications increasing serum potassium: Risk of hyperkalemia 2

Common Pitfalls to Avoid

• Do not assume ciprofloxacin is safe in children just because it's occasionally used; it requires specific serious indications 1
• Do not overlook drug interactions with common supplements containing calcium, magnesium, aluminum, iron, or zinc—these must be separated by 2-6 hours 1
• Do not continue ciprofloxacin if tendon pain, swelling, or inflammation develops; stop immediately and contact your provider 1
• Do not use ciprofloxacin for viral infections like common cold or flu—it is ineffective against viruses 1