Can Hydralazine cause knee pain and weakness be due to Hydralazine? I take 10 mg of Hydralazine 3 times a day. After about 3 to 4 hours taking it, there is no pain. If I accidently miss dose, there is no pain. My doctor doesn't think this is due to hydralazine. He says I have arthritis. But when I Was taking Amlodipine, my angle swelled with severe pain. My doctor didn't think it was due to Amlodipine. Only after he did a lot of tests, he agreed it was Amlodipine and changed me to Hydralazine. What should I do? What are the other side effects that people experience with hydralazine?