Sodhi M, et al. – The purpose of this study was to quantify the risk of secondary pseudotumor cerebri syndrome (PTCS) with fluoroquinolones. With current users of fluoroquinolones, the study proposed an increase in the risk of PTCS. Patients who experienced symptoms of raised intracranial pressure including headaches, tinnitus, and double vision while taking fluoroquinolones had to seek medical attention although this adverse event was rare.

• The authors conducted a case-control study of people 15-60 years of age from the LifeLink Database (QuintilesIMS Parsippany, NJ).
• For this study, cases had the first ICD-9-CM code for benign intracranial hypertension (BIH) as well as having received a procedure code for an MRI or CT scan and a lumbar puncture within 15 days or 30 days of the BIH code.
• They selected 10 controls using density-based sampling for each case.
• Current users of fluoroquinolones received a prescription within 15 days or 30 days of the date of the diagnosis.
• Risk periods for 30 and 60 days were also examined for the sensitivity analysis.
• They computed adjusted rate ratios (RRs) from a conditional logistic regression model.

• There were 339 cases of PTCS and 3,390 corresponding controls from a cohort of 6,110,723 people.
• The adjusted RR for current users of fluoroquinolones for both the 15-day and 30-day definitions were 5.67 (95% confidence interval [CI] 2.72–11.83) and 4.15 (95% CI 2.29–7.50), respectively in the primary analysis.
• With RRs for 15 and 30 days of current use of 2.68 (0.89–8.11) and 3.64 (1.67–7.91), respectively, the risk with tetracycline antibiotics was also increased.