Levaquin Side Effects: Did Levaquin mixed with Asthma medicines kill my 32 year old daug http://www.medications.com/effect/view/37250 Did Levaquin mixed with Asthma medicines kill my 32 year old daughter. I believe she died of Cardio Arrhythmia. It is very possible. One of the listed side effects of Levaquin Wed, 17 Dec 2008 11:49:42 -0500 http://www.medications.com/effect/view/37250?item=15326 It is very possible. One of the listed side effects of Levaquin is fatal arrhythnia called Long Q-T syndrome. You should look into this. I'm so sorry for your loss. http://www.medications.com/effect/view/37250?item=15326