Meftal (Mefenamic acid) only helps lower fever temporarily; it does not cure the underlying infection. I cannot recommend an antibiotic because antibiotics only treat bacterial infections, not viral ones. Misusing antibiotics can lead to harmful side effects and drug resistance. Since your fever is not responding to Meftal, you need a proper medical evaluation to find the root cause. Please consult a doctor immediately. They can perform necessary tests (like a blood test) to diagnose the infection and prescribe the correct, targeted treatment. For now, please stay well-hydrated, rest, and avoid self-medicating with antibiotics.