What are the side effects of Ciprofloxacin (ciprofloxacin)?

Ciprofloxacin Side Effects

Ciprofloxacin carries serious, potentially disabling side effects that require immediate discontinuation if warning signs develop, including tendon rupture, peripheral neuropathy, CNS effects, cardiac arrhythmias, and severe allergic reactions. 1

Most Serious Side Effects Requiring Immediate Action

Tendinopathy and Tendon Rupture

• Tendon rupture is the most critical musculoskeletal risk, most frequently affecting the Achilles tendon and potentially requiring surgical repair 1
• Risk is markedly elevated in patients over 60 years, those taking corticosteroids, and transplant recipients (kidney, heart, or lung) 1
• Tendon rupture can occur during treatment or up to several months after completion of therapy 1
• Stop ciprofloxacin immediately at the first sign of tendon pain, swelling, or inflammation and advise complete rest 1

Peripheral Neuropathy

• Permanent nerve damage can occur in the arms, hands, legs, or feet 1
• Warning symptoms include pain, burning, tingling, numbness, or weakness in extremities 1
• Discontinue ciprofloxacin immediately if any peripheral neuropathy symptoms develop to prevent irreversible damage 1

Central Nervous System Effects

• CNS reactions may occur after the first dose and include seizures, increased intracranial pressure, and toxic psychosis 1
• Additional CNS effects: dizziness, confusion, tremors, hallucinations, depression, suicidal thoughts, anxiety, paranoia, and nightmares 1
• Stop ciprofloxacin immediately if any CNS symptoms develop 1
• Use extreme caution in patients with known seizure disorders or conditions that lower seizure threshold 1

Cardiac Effects (QT Prolongation)

• Ciprofloxacin causes QT interval prolongation leading to potentially fatal torsades de pointes 1
• Highest risk in elderly patients, those with family history of QT prolongation, hypokalemia, or concurrent antiarrhythmic use 1
• Discontinue if patient develops irregular heartbeat or faints 1

Severe Allergic Reactions

• Anaphylaxis can occur after a single dose 1
• Manifestations include hives, throat tightness, swelling of lips/tongue/face, difficulty breathing or swallowing, and cardiovascular collapse 1
• Stop ciprofloxacin immediately at first sign of skin rash, as this may herald a severe hypersensitivity reaction 1

Common Side Effects

Gastrointestinal Effects

• Most frequent adverse effects: nausea, vomiting, diarrhea, and abdominal discomfort occurring in 2-8% of patients 2
• Overall gastrointestinal side effects reported in 4.9-5% of patients 3, 4

Hepatotoxicity

• Stop ciprofloxacin immediately if yellowing of skin or eyes or dark urine develops, indicating potential liver injury 1
• Transient elevations in liver enzymes may occur but are usually reversible 2

Clostridioides difficile Colitis

• Pseudomembranous colitis can develop during treatment or up to 2 months after completion 1
• Contact provider immediately for watery diarrhea, persistent diarrhea, bloody stools, or fever with abdominal cramping 1

Metabolic Effects

• Hypoglycemia can occur, particularly when combined with oral antidiabetic agents like glyburide 1
• Metabolic-nutritional effects reported in 4.4-4.6% of patients 3, 4

Photosensitivity

• Severe sunburn, blisters, or skin swelling can occur with sun exposure 1
• Avoid sunlamps and tanning beds; use sunscreen and protective clothing if sun exposure is unavoidable 1

Pediatric Considerations

• Arthropathy occurs in 9.3% of children versus 6.0% in controls 5
• Joint problems are more common in children under 18 years 1
• Permanent cartilage lesions have been documented in immature animals 1

Critical Drug Interactions

CYP1A2 Inhibition

• Ciprofloxacin inhibits CYP1A2 enzyme pathway, leading to dangerous interactions with clozapine, theophylline, methylxanthines, and tizanidine 5, 6, 1
• Serious and fatal reactions have occurred with concurrent theophylline use, including cardiac arrest, seizures, status epilepticus, and respiratory failure 1
• Monitor theophylline levels closely if concomitant use is unavoidable 1

Overall Safety Profile

• Total incidence of adverse reactions ranges from 9.3-13.4% depending on dosage and population 3, 2
• Most reactions (94%) are mild to moderate in severity 3
• Treatment discontinuation due to side effects occurs in only 1.5% of patients 3
• Severe reactions occur in 0.6% of treated patients 3

Monitoring Recommendations

• Medical organizations recommend vigilant monitoring and prompt discontinuation if concerning symptoms develop 6
• The key principle is immediate cessation at the first sign of serious adverse effects rather than attempting to manage through symptoms 1