Gabapax ointment (used for nerve pain) and Flexabenz ointment (used for muscle pain) should only be used together if your doctor advises it. If you are told to use both, apply a thin layer of one and let it fully absorb before applying the other. Another option is to use them at different times of the day to avoid skin irritation or interactions. It is always best to check with your doctor before combining topical medications. They can guide you on the safest and most effective way to use them, whether that means alternating between the two or sticking with just one based on your symptoms.