Am J Geriatr Psychiatry 11:470-471, August 2003
© 2003 American Association for Geriatric Psychiatry

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Letter

Gatifloxacin Precipitation of Psychosis in Alzheimer Disease
Roy R. Reeves, D.O., Ph.D.


SIR: Gatifloxacin is an 8-methoxy-fluoroquinolone antibiotic that was approved for use in the United States in December 1999. It is a well-tolerated agent, with activity against a wide range of gram-positive and -negative and atypical organisms.1 Described here is a patient with Alzheimer disease (AD) who developed significant psychotic symptoms associated with treatment with gatifloxacin.

The patient is an 86-year-old man with AD that had begun with memory problems at about age 81. A complete work-up did not reveal any other etiology of the dementia. Medical history was significant for hypertension and Type II diabetes, well controlled with enalapril and glyburide. He was able to live at home with assistance from his wife and had shown no signs of psychosis.

He developed bacterial bronchitis, and treatment with gatifloxacin 400 mg daily was begun. On the third day of treatment, he was noted to be agitated and complained of seeing strange people in his house. After 6 days, the bronchitis had resolved, but he was more agitated and talking about people trying to kill him. Gatifloxacin was discontinued, and risperidone 0.25 mg qd was prescribed. The psychotic symptoms worsened, and he had to be hospitalized after threatening his wife and starting to carry a gun and hatchet to protect himself. MRI of the brain revealed generalized atrophy. Chest x-ray, urinalysis, CBC, and chemistry survey were unremarkable except for mild elevation of the BUN (24 mg/dL) and creatinine (1.3 mg/dL). Risperidone was gradually increased to 0.5 mg bid, resulting in noticeable decrease of paranoia over several days. He was able to return home, and, after a month, the dosage was tapered to 0.25 mg qd. After another month, the medication was discontinued. He has not had a recurrence of hallucinations or delusions in the subsequent several months.

It is likely that the precipitation of the patient's psychotic symptoms occurred as a result of the initiation of gatifloxacin treatment because of the close temporal relationship of the events. Although fluoroquinolones are considered to be safe and well tolerated, adverse effects involving disturbances of the CNS occur at an overall frequency of 1%–2%.2 The most common symptoms are headache, drowsiness, and dizziness; other, less common, effects are restlessness, insomnia and sleep disorders, agitation, and vision changes. Seizures have occurred rarely, usually in patients with predisposing factors. Hallucinations and psychosis have been reported with ciprofloxacin treatment,3 and ofloxacin has been rarely associated with acute psychosis.4

CNS-adverse effects of gatifloxacin are typically mild, including dizziness (3%), headache (3%), and abnormal dreams, insomnia, tremor, and vertigo in less than 3% of patients.2 However, an 87-year-old woman with AD developed generalized seizures and myoclonus while receiving gatifloxacin for a urinary tract infection.5 AD and similar neurological disorders may be predisposing factors, rendering patients with these disorders more vulnerable to CNS-adverse effects of gatifloxacin and other fluoroquinolones. Elimination of gatifloxacin is primarily renal excretion of the unchanged drug, and impaired renal function (possibly of some significance in this case) may pose an additional risk in elderly patients.


FOOTNOTES

Chief of Psychiatry

G.V. (Sonny) Montgomery VA Medical Center (116A)

1500 E. Woodrow Wilson Drive

Professor of Psychiatry and Neurology

University of Mississippi School of Medicine

Jackson, MS 39216

e-mail: roy.reeves@med.va.gov

REFERENCES


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