Welcome to Just Answer. Simvastatin is the generic for Zocor which can cause muscle problems. This is a breakdown in muscle fiber with accompanying pain. It can happen from trauma, alcohol, as a result of blood clots, or overuse of some drugs including statins like simvastatin. Usually the pain improves when the drug is withdrawn and the muscle begins to heal.
If your doctor is not looking for the source of the pain, that would be the first step. Especially since the pain has not improved in 5 weeks, that makes it less likely that the drug was the cause in the first place. You should be checked for blood clots, and for proper blood flow in the extremities. Here is the contact office for Dr. Reddy's, including their North American generics division.
Dr. Reddy's Laboratories Inc.
3600 Arco Corporate Drive, Suite 310 Charlotte, NC 28273
Tel: +1(NNN) NNN-NNNN
I definitely agree that you need a second opinion since your first doctor has not provided more information, or run any tests to see what is going on with your leg pain.
I also read Dr. Mark's answer (neurosurg) and agree with all he had to say. Typically statins begin to cause trouble after several months' use and the pain will begin to recede when the drug is withdrawn. My colleagues and I have prescribed statins thousands of times and have never seen anyone have such a reaction after just one dose. There is no mention in the medical literature of such an occurrence.
The important thing is that you get treatment, regardless of what the source of the problem is or was. While we can all speculate (including Dr. Reddy's labs), the only way to determine the cause is testing. My advice would be to set up an appointment with another doctor on Tuesday.