What are the side effects of Cipro (ciprofloxacin)?

Ciprofloxacin Side Effects

Ciprofloxacin carries serious risks including tendon rupture, peripheral nerve damage, CNS effects, and cardiac arrhythmias that can be disabling and potentially permanent, with the FDA warning these should limit its use to situations where no safer alternatives exist. 1

Most Serious Side Effects (Boxed Warnings)

Tendon Complications

• Tendinitis and tendon rupture can occur in all ages, most frequently affecting the Achilles tendon and potentially requiring surgical repair. 1
• Risk factors include age over 60 years, concurrent corticosteroid use, kidney/heart/lung transplants, renal failure, and previous tendon disorders like rheumatoid arthritis. 2, 1
• Tendon rupture can occur during treatment or up to several months after completion of therapy. 1
• Discontinue ciprofloxacin immediately if tendon pain, swelling, or inflammation develops. 2, 1

Peripheral Neuropathy

• Permanent nerve damage to arms, hands, legs, or feet can occur, presenting as pain, burning, tingling, numbness, or weakness. 1
• Stop ciprofloxacin immediately if symptoms of peripheral neuropathy develop to prevent permanent damage. 1

Central Nervous System Effects

• Seizures, increased intracranial pressure, and toxic psychosis have been reported. 1
• CNS effects may occur after the first dose and include dizziness, confusion, tremors, hallucinations, depression, anxiety, paranoia, and rarely suicidal thoughts. 1
• Avoid use in patients with known CNS disorders that predispose to seizures or lower seizure threshold. 1

Cardiac Effects

• QT interval prolongation can lead to fatal dysrhythmias (torsade de pointes). 2, 1
• Higher risk in elderly patients, those with family history of prolonged QT, low potassium levels, or concurrent use of antiarrhythmic medications. 1

Common Side Effects

Gastrointestinal (Most Frequent)

• Nausea occurs in 0.5-1.8% of patients and represents the most common side effect. 2
• Other GI effects include diarrhea, vomiting, and abdominal discomfort, affecting 2-8% of patients. 3, 4

Other Common Effects

• Headache and dizziness affect 1-4% of patients. 1, 4
• Skin rash or pruritus occurs in approximately 1% of patients. 1, 4
• Vaginal yeast infections in women. 1

Serious but Less Common Side Effects

Severe Allergic Reactions

• Anaphylactic reactions can occur after the first dose, requiring immediate emergency treatment with epinephrine. 1
• Manifestations include hives, difficulty breathing/swallowing, facial swelling, throat tightness, and rapid heartbeat. 1
• Severe skin reactions including Stevens-Johnson syndrome and toxic epidermal necrolysis have been reported. 1

Hepatotoxicity

• Yellowing of skin or eyes (jaundice) and dark urine indicate potential liver damage requiring immediate discontinuation. 1
• Acute hepatic necrosis or failure has been reported rarely. 1

Clostridioides difficile Colitis

• Pseudomembranous colitis can occur during treatment or up to 2+ months after completion. 1
• Contact provider immediately for watery diarrhea, persistent diarrhea, bloody stools, stomach cramps, or fever. 1

Blood Sugar Changes

• Hypoglycemia can occur, particularly when combined with oral diabetes medications like glyburide. 1

Special Population Concerns

Pediatric Patients

• Arthropathy occurs in 9.3% of pediatric patients (ages 1-17) compared to 6.0% in controls. 2
• Joint problems can develop during or after treatment. 1
• Use only for specific indicated infections where benefits outweigh risks. 2, 1

Pregnancy and Lactation

• Safety has not been established in pregnant or lactating women; avoid use unless benefits clearly outweigh risks. 1
• Teratogenic effects have been documented. 2

Critical Drug Interactions

CYP1A2 Inhibition

• Ciprofloxacin inhibits CYP1A2 enzyme, causing dangerous elevations of theophylline, tizanidine, clozapine, and other substrates. 2, 1
• Serious and fatal reactions with theophylline include cardiac arrest, seizures, status epilepticus, and respiratory failure. 1

Absorption Interference

• Multivalent cations (magnesium, aluminum, iron, calcium) in antacids, supplements, and dairy products drastically reduce ciprofloxacin absorption. 2
• Take ciprofloxacin at least 1-2 hours before or 4 hours after products containing these cations. 2

Photosensitivity

• Skin becomes sensitive to sunlight, sunlamps, and tanning beds, potentially causing severe sunburn, blisters, or skin swelling. 1
• Use sunscreen, wear protective clothing, and limit sun exposure during treatment. 1

Overall Safety Profile

• In clinical trials of 9,473 patients, total side effect incidence was 9.3-10.2%, with 94% being mild to moderate. 3, 5
• Treatment discontinuation due to side effects occurred in only 1.5% of patients, mostly for GI reactions. 3
• Severe reactions occurred in 0.6% of patients. 3