Aseptic meningitis is meningitis with negative bacterial cultures. Overall, viral infections are the most common etiology, however medications can also cause this illness.
Well known causes of aseptic meningitis include: antimicrobials (particularly sulfamethoxazole/trimethoprim), NSAIDS, antivirals (valacyclovir), and antiepileptics.
Recently an abstract was published that suggests that patients on levetiracetam have a higher risk of developing aseptic meningitis than those on topiramate and gabapentin. Lamotrigine has also been implicated, but appears to have a lower risk than levetiracetam, topiramate and gabapentin.
Teigland C, Chen P, Parente A, Bhattacharjee R. FDA Black Box Warning on Risk of Aseptic Meningitis with Use of Antiepileptic Drug Lamotrigine: Comparative Risk of Alternative Medications. Abstract, American Epilepsy Society. 2013
http://www.aesnet.org/go/publications/aes-abstracts/abstract-search/mode/display/st/parente/sy/2013/sb/Authors/id/1751398