Question: Brief Answer:
Most likely from flu

Detailed Answer:
Hello, I'm Dr. Branch, thanks for using 'Ask a Doctor'. Muscle aches, or myalgia, is very common with the flu, especially in the calf muscles, and so even though the muscle aches are there at the beginning, I would still suspect this is from the flu. Also, muscle aches are not a known side effect from Tamiflu.

Normally these aches should improve and completely resolve in the next few days. If they continue to worsen, or you are still having significant pain after several days, I would suggest seeing your doctor to make sure you are not having more serious muscle damage, which can rarely happen with viral illnesses like the flu.

I hope that helps, please let me know if you have any other questions about that, and I would be glad to discuss it with you further.

i was diagnosed with type B flu on thursday and have been taking tamiflu 2x a day since thursday. most of my symptoms are gone except a slight cough, but beginning saturday morning - both of my calves began to ache. they both feel as though they just had a XXXXXXX horse, very sore in the muscle. ibuprofen helps, and the pain is more prominent when flexing my feet.

is this common with the flu, and if so, when can i expect the ache to resolve? i have no other muscular pain. if not common with the flu, is this a side effect of tamiflu?