Case Presentation:

A 62–year–old male with a history of hypertension and dyslipidemia presented to the emergency room with distal extremity paresthesia and proximal muscle weakness. Ten days prior, he noticed dysuria and tried over–the–counter phenazopyridine without relief. He was seen by his physician, who prescribed ciprofloxacin for urinary tract infection. On day 1 of ciprofloxacin, he experienced numbness and tingling in his distal extremities. On day 3, he noticed problems with depth perception and discontinued ciprofloxacin. He reported progressive weakness and inability to arise from a supine position. Prior to this, the patient was healthy and denied recent respiratory or diarrheal illness. Neurologic examination revealed areflexia, 2/5 proximal muscle strength, 4/5 distal muscle strength, diminished sensation to light touch bilaterally in the distal extremities with position and vibration senses intact. Two days later, he exhibited diminished sensation, proprioception, and vibration to his mid leg. Pain and temperature senses remained intact. Electromyography revealed prolonged distal motor latencies and prolonged distal ulnar sensory latency suggesting a demyelinating component compatible with significant polyneuropathy. Tests for HIV, VZV, HSV, Mycoplasma pneumonia, Cryptococcus, and Enterovirus were negative. TSH and vitamin B12 were within normal limits. CSF analysis didn’t reveal an albumino–cytologic dissociation; however, the diagnosis of Guillain–Barré Syndrome (GBS) was consistent with his presentation of quadriparesis, areflexia, and distal sensory loss. IVIG therapy was initiated, and the patient regained most of his strength, but experienced mild paresthesia and mild ataxia 2 months post hospitalization.

Discussion:

Fluoroquinolones are associated with adverse CNS effects such as nausea, vomiting, and headache in 0.9–4.4% of patients. Symptoms are generally mild and reversible upon treatment cessation. Severe adverse drug events (ADEs) such as phototoxicity, cardiotoxicity, and seizures are rare. Peripheral nervous system (PNS) disturbances include paresthesia, numbness, pain, and muscle weakness, but symptoms usually resolve within 2 weeks after treatment cessation. However, in ADE cases examined by survey (N= 45), PNS symptoms associated with fluoroquinolones lasted more than 3 months in 71% of cases and more than 1 year in 58%. One case report of GBS during ofloxacin treatment for a UTI was found. No publications regarding phenazopyridine use and peripheral neuropathy could be found. While a causal relationship cannot be established, the close temporal association between ciprofloxacin therapy and GBS onset in a healthy patient highlights a rare, but serious ADE potentially associated with ciprofloxacin. New–onset peripheral neuropathy in patients taking fluoroquinolones should be critically examined.

Conclusions:

The purpose of reporting this case is to increase awareness of ADEs associated with fluoroquinolone use and provide an up–to–date literature review.