Answer
Usually not. Both are NSAIDs, and combining them increases the risk of gastrointestinal bleeding, kidney injury and other adverse effects unless specifically supervised.
Sources for this answer
- Mefenamic Acid 500 mg Tablets — Current selected SmPCemc · Summary of Product Characteristics
- Mefenamic Acid 50 mg/5 ml Suspension — Current selected SmPCemc · Summary of Product Characteristics
- Mefenamic Acid 250mg Capsules — Current selected SmPC