Levothyroxine Sodium Side Effects: For the last year and a half I have taken Levothyroxine Sodium 50 http://www.medications.com/effect/view/40101 For the last year and a half I have taken Levothyroxine Sodium 50mg, now increased to 75 mg. I have gained a great deal of weight and developed arthritis in both knees. Some days my knees hurt so bad I can hardly get out of bed. Since my medication was incr Hi there. I presume you have been diagnosed with undedractive thy Sun, 31 May 2009 05:54:14 -0400 http://www.medications.com/effect/view/40101?item=20237 Hi there. I presume you have been diagnosed with undedractive thyroid and unfortunately if you are in the UK there is no other treatment available under the NHS. If you visit www.tpa-uk.org.uk you will find a wealth of information to help you and a forum f http://www.medications.com/effect/view/40101?item=20237