It is often advised that over-the-counter analgesics should be avoided since they are usually not very effective and can often cause rebound
headaches. Although, there are other analgesics that can be used if the
headaches are very severe such as barbiturates and opiates. These medications are not usually as effective for migraine headaches, and they can have high side-effect profiles and high-dependency profiles. Also, I am fairly sure that barbiturates can cause rebound headaches too.