http://www.webmd.com/osteoarth...-may-rupture-tendons
This warning has been around since 2008, but I don't think most people know about it. Cipro can cause ruptured tendons. If you are allergic to Penicillin, like me, you may be prescribed Cipro.
The warning applies to drugs of the fluoroquinolone class, including Cipro, Cipro XR, Proquin XR, Levaquin, Floxin, Noroxin, Avelox, Factive, and marketed generics.
...the drugs can increase risk of tendinitis and tendon rupture in some patients.
spontaneous ruptures occur in about one in 100,000 people. The agency says taking the drugs appears to triple or quadruple the risk.
Most of the tendinitis and tendon ruptures affect the Achilles tendon, behind the ankle. But the agency has also received reports of tendinitis and ruptures in the shoulder and hand. Tendons connect muscle to bone.
Researchers don't know exactly what fluoroquinolones do that promotes tendon rupturing. Theories suggest the drug may impede collagen formation or interrupt blood supply in joints, Albrecht says.
She says patients taking the drugs should tell their doctors immediately if they experience soreness or inflammation in muscles or tendons and that they should not exercise affected joints.
Add this to the list of possible causes of pitching injuries.