The name varies. You'll see these headaches called "rebound headaches," "analgesic rebound headaches," "medication overuse headaches," and other terms. The newer term in use by specialists in the field of headache and Migraine disease treatment is "medication overuse headache" (MOH), and that's what I'll be using here because it truly does seem to be the most accurate.

Every person who has headaches or Migraine disease should be told about MOH by our doctors because knowing about it in advance could save us a great deal of pain. Unfortunately, we're not. If your doctor has prescribed any medication for you to take when you have headaches or Migraines such as triptans, ergotamines, pain medications, etc., or recommended that you take over-the-counter medications such as acetaminophen, etc., and has not told you about their potential to cause MOH, ask him or her about it. Find out what the potential for MOH is with the medications they're prescribing or recommending.

There have been nearly as many questions as answers about MOH for quite some time now, especially regarding which types or classes of medications can cause MOH. Those questions haven't been easy to answer because, for some time, there wasn't a clear enough consensus about which medications could induce MOH. Studies with empirical evidence were lacking, and conflicting opinions among experts easily left us to think one way one day and another way the next. While it's highly unlikely that everyone in any field will ever agree, today there's at least a fair consensus regarding the issues related to MOH. To help us avoid medication overuse headache and deal with it if it occurs, there are issues we need to explore:

1. What is MOH?
2. What medications cause it?
3. How can we avoid MOH?
4. How can we distinguish MOH from other headaches and Migraines?
5. How do we stop MOH?
6. Will taking pain medications for pain other than head pain cause MOH?

What is Medication Overuse Headache?
The best explanation of MOH comes from the The International Classification of Headache Disorders, 2nd Edition, from International Headache Society. For the sake of clarity and brevity, I'll paraphrase:

     Medication-overuse headache is an interaction between a medication used excessively and a susceptible patient...
     ... What is crucial is that treatment (resulting in MOH) occurs both frequently and regularly, i.e., on several days each week...
     ...the headache associated with medication overuse often has a peculiar pattern shifting, even within the same day, from having migraine-like characteristics to having those of tension-type headache (i.e., a new type of headache).
     The diagnosis of medication-overuse headache is clinically extremely important because patients rarely respond to preventative medications whilst overusing acute medications.

What medications can cause MOH?
This has long been one of the biggest questions about MOH. There is now sufficient research to address many of our questions. According to Goadsby, et al, "There is now substantial evidence that all drugs used for the treatment of headache may cause MOH in patients with primary headache disorders." When they say, "headache," they mean headache and Migraine both. So, just which medications can cause MOH?

• Triptans. A point of confusion has been whether triptans such as sumatriptan (Imitrex) could cause MOH. Studies have now been published demonstrating MOH resulting from sumatriptan (Imitrex) naratriptan (Amerge), zolmitriptan (Zomig), and rizatriptan (Maxalt). Because almotriptan (Axert), eletriptan (Relpax) and frovatriptan (Frova) were introduced much more recently, there are no studies proving or disproving their causing MOH.
• Ergotamines such as DHE, Migranal, Cafergot.
• Simple analgesics such as acetaminophen.
• Opioids such as Codeine and Diluadid.
• Combination medications such as:
  • Butalbital compounds containing aspirin or acetaminophen, butalbital, and caffeine.
  • Vicodin, which contains acetaminophen and hydrocodone.
  • Other compounds containing more than one medication.

How can we avoid MOH?
Medication overuse headache is avoided by not using medications for the relief of headache and/or Migraine more than two or three days a week. Although that statement may look simple, for the chronic sufferer, it's anything but a simple solution. For those who take triptans, doctors will sometimes recommend taking triptans two days a week and another type of medication another two days a week if absolutely necessary. Beyond that, there is no real answer for pain on additional days that week. The long-term answer is, of course, an effective preventive regiment that reduces the need for MOH-causing medications.

How can we distinguish MOH from other headaches and Migraines?
Differentiating between a tension-type headache, for example, and MOH can be difficult. There are, however, some very discernable differences between MOH and a Migraine attack. Migraine pain is worsened by activity; MOH tends not to be. MOH is also missing other Migraine symptoms such as nausea, vomiting, phonophobia, photophobia, hot flashes, chills, dizziness, and so on.

How do we stop MOH?
Immediately discontinuing the medication causing the MOH is the preferred plan of action. It's obviously the quickest, and it doesn't add more medications to an already confused body. According to Goadsby, et al, withdrawal symptoms usually last two to 10 days. Those symptoms may include: withdrawal headache, vomiting, arterial hypotension, tachycardia, sleep disturbances, restlessness, anxiety, nervousness. In some cases where the MOH is being caused by medications such as butalbital compounds that have been taken daily in large amounts, seizures can occur if the medication is abruptly withdrawn, so a tapered withdrawal or supervised detoxifications is necessary. The best approach is to ask your doctor for help and advice. When you take these medications for pain, you don't become addicted, but you may become dependent upon them. This is a medical issue. Don't be reluctant to discuss it with your doctor. Depending on the medication involved and the situation, some doctors may recommend hospitalization or prescribe medications to help you get out of the MOH cycle.

Will taking pain medications for pain other than head pain cause MOH?
I posed these two questions to Dr. Stewart Tepper of the New England Center for Headache: Does a Migraineur need to be careful about developing MOH from meds taken for pain other than head pain? Is this situation different for Migraineurs and non? His reply was:

Which comes first, chicken or egg? Increased medication use or increased headaches? To answer this question and so assist in establishing causality, we may require reports of patients with episodic migraine who use analgesics or anti-inflammatories for a purpose other than headache and who then developed CDH. Bahra et al reported on 105 patients in a rheumatology clinic who took regular and mixed analgesics and anti-inflammatories for arthritic pain and not for headache. Chronic daily headache was present in 8 (7.6%) of these patients, and all had a history of previous episodic migraine. Regular analgesic use preceded or coincided with onset of CDH in 7 of these 8 patients. No patient lacking a previous history of migraine developed CDH.
    Wilkinson et al studied 28 patients who underwent total colectomy for ulcerative colitis; patients with a previous history of CDH were excluded. Eight of the 28 patients used opioids at least 5 days per week. All patients with a previous history of migraine who overused opiates developed CDH, whereas no patient lacking a history of prior migraine who overused opiates did so. While it might be argued that the development of CDH was the cause of, not result of, analgesic overuse, these patients were taking opiates not because of increased headache, but rather to decrease the number of bowel movements. The authors concluded that frequent opiate use could produce CDH in susceptible individuals, and that patients with previous headache had a particular susceptibility to this outcome.
     These two small studies suggest that overuse of analgesics, in the absence of increased frequency of headache and for purposes other than the treatment of headache, can result in the precipitation of CDH.
     Further, Isler, in 1982,  studied 235 patients with CDH between1978-1981. He stated: “Withdrawal of attack drugs alone [i.e. without other rx] led to a marked reduction of frequency of headache, indicating that excessive intake of these drugs is much more a cause than a consequence of frequent and chronic migraine. This conclusion is supported by the observation of relapses of … chronic headache when further administration of analgesics was necessary for other ailments. Of the 87 patients who showed improvement [after detoxification] by a decreased frequency of attacks, 51 had one or more relapses into their former medication habit, always leading to a higher frequency of headache. Their relapses were induced by dental problems and their treatment by analgesics,... [and] by common respiratory infections and their treatment by analgesics."