http://www.medications.com/effect/view/36953 I took Levaquin 750 for 10 days for a sinus infection. I took first 5 doses, went to see my doctor again 6 days later because I was still sick. She prescribed again 5 does of Levanquin 750. I am still coughing and I feel very tired. It did not help at all. Sat, 29 Nov 2008 14:32:07 -0500 http://www.medications.com/effect/view/36953?item=14902 Yes it is related to the levaquin. Stop Taking this drug!!! It has a black box warning and will damage your tendons. Levaquin is in a class of antibiotics called fluroquinolone, Levaquin has been linked to tendon damage and ruptures in the Achilles tendon http://www.medications.com/effect/view/36953?item=14902 Thu, 09 Apr 2009 22:37:19 -0400 http://www.medications.com/effect/view/36953?item=18752 it is a very bad drug and took me years to figure that I couldn't take the drug or any sulfer drugs for that matter. It started for me 6 years ago and took me until this year to figure out what happened. My tendon is badly damaged and my calves cramp also! http://www.medications.com/effect/view/36953?item=18752