Hi friend, Thanks for your query. Forecox contains three drugs, of which, Isoniazid can cause tingling, burning, numbness or shock-like sensations in the limbs. However, none of the drugs cause severe joint pains. If you have burning sensation in the limbs, then, Folic Acid (one of the Vitamin B) has to be taken in low doses. But, if the problem is confined to pain, you need to get yourself evaluated for a possible co-existing medical condition. If you find my response helpful and informative, do not forget an “excellent” (5-star rating) to my answer, to ENCOURAGE ALL doctors- engaged in social service- to render sound advice to the FREE queries. Take care Dr. Rakesh Karanwal