What is Medication-Overuse Headache?
Medication-overuse headache (MOH) is a common disorder that causes a lot of discomfort and distress. It can transform occasional headaches into chronic ones. This condition has many names, including analgesic rebound headache, drug-induced headache, or medication-misuse headache. It occurs when people suffering from frequent primary headaches like migraines or tension-type headaches, take too much medication. This overuse can unintentionally increase the intensity and frequency of their headaches, creating a harmful cycle of more medicine use and more frequent headaches.
This can turn the treatment (the medication) into the actual cause of their problem (MOH). It’s also worth noting that even individuals who are susceptible to headaches and take painkillers for other medical conditions can also develop MOH.
Doctors first recognized MOH back in the 1930s. They noticed that headaches would last longer when patients overused a medicine called ergotamine. In the 1970s and 1980s, they saw a link between MOH and other painkillers such as barbiturates, codeine, and mixed analgesics. They also observed that patients’ headache frequency dropped when they stopped taking these drugs. For a while, it was known as transformed migraine.
In 1988, the disorder was first defined in the International Classification of Headache Disorders (ICHD) as a “headache caused by the chronic use or exposure to a substance”. The term MOH was officially used in the second edition of ICHD (2004), with different subtypes based on the specific medicine that was overused, such as ergotamines, triptans, opioids, etc.
What Causes Medication-Overuse Headache?
Medication overuse headache is a type of secondary or chronic headache described in the most recent ICHD-3 (2018) medical manual. It occurs due to overuse of medications for treating a previous existing headache. The specific type of this headache depends on the medication that was overused. The general criteria for diagnosing this condition are: a person has headaches on 15 or more days per month, they’ve been overusing one or more headache medications for longer than three months, and the symptoms can’t be better explained by another medical condition. If more than one medication is being overused, each should be coded during diagnosis. The headache usually mirrors the original headache problem. Typically, this type of headache stops when the person discontinues the medication. For diagnosis, both the original and the medication overuse headache are identified.
As you might guess, the biggest risk factor for a medication overuse headache is chronic overuse of headache medication. Risk levels are different for each type of medication, from lowest to highest, they are: migraine medications called triptans or ergotamine, single painkillers like NSAIDs or acetaminophen, and combination painkillers containing opioids or barbiturates. It’s been observed that these combination painkillers, especially those with opioids or barbiturates, can double the risk of medication overuse headaches. Some studies suggest that NSAIDs, a type of painkiller, may help protect against these headaches for people who get a headache ten or fewer days a month.
Risk Factors and Frequency for Medication-Overuse Headache
Medication overuse headache (MOH) affects around 0.5 to 2.6% of the general population. However, the actual number is hard to determine due to differing diagnostic standards. There are higher instances of it in certain countries like Russia (7.6%) and Iran (4.6%) because it’s more common for medication to be misused there. In specialized headache centers, MOH is more prevalent in patients with chronic headaches, occurring in 11 to 70% of cases, which is considerably more than the general population. About 80% of people with MOH have migraine, but others have tension-type or post-traumatic headaches.
This condition usually affects people between 30 to 50 years of age, and is more common in females than males by a ratio of 3 or 4 to 1. Surprisingly, between 21 and 52% of children and 35% of adults over 64 years of age meet the criteria for MOH. This condition is more common in first-generation migrants in Europe and can be influenced by various factors, including socio-economic conditions, genetic predisposition, and cultural factors. As this problem occurs worldwide, it’s believed to be connected to economic, psychological and physical disabilities.
- Major risk factors for MOH include:
- Demographics such as being under 50 years of age, being female, and having a low educational level.
- Self-reported complaints like chronic musculoskeletal and gastrointestinal complaints, and anxiety or depression.
- Lifestyle factors such as smoking, physical inactivity, metabolic syndrome, and high daily caffeine intake.
- Usage of certain medications like tranquilizers, aspirin, ibuprofen, and opioids.
Of all people with MOH, those who misuse opioids and triptans are more likely to exhibit behavior akin to dependency. Research has found that MOH may share common neurobiological pathways with substance use disorders. It’s believed that there may be a biological predisposition to MOH. Migraines are the most common type of headache associated with MOH, with about 80% of patients with MOH also having migraines. People with more frequent headaches are also at a higher risk for MOH. There’s debate on whether taking more medication due to frequent headaches leads to MOH, or if these high-frequency patients are simply more susceptible to it. A family history of MOH or substance abuse (drugs or alcohol) triples the risk of developing MOH.
Many patients with MOH also suffer from mood disorders such as anxiety and depression. About 40% of MOH patients meet the criteria for depression, and up to 58% have anxiety. However, it’s unclear whether these psychiatric conditions are contributing factors to MOH or its consequences. People with tension headaches have been found to have the highest incidence of associated psychiatric conditions. Patients with MOH are also more likely to have issues with drug dependency, and obsessive-compulsive disorder (OCD).
Medicines that can cause MOH, arranged from highest to lowest incidence, include:
- Opioids, butalbital-containing combination analgesics, and acetaminophen-aspirin-caffeine combinations.
- Triptans.
- Non-steroidal anti-inflammatory drugs (NSAIDs).
- Calcitonin gene-related peptide antagonists.
Signs and Symptoms of Medication-Overuse Headache
For a diagnosis of Medication Overuse Headache (MOH) to be considered, there are specific criteria that need to be met. It’s important to examine a patient’s full medical history, especially their history of headaches, medication use, and substance abuse. A patient must be experiencing regular headaches (15 or more days per month) that are linked to a pre-existing headache disorder like a migraine or tension-type headache. Additionally, they should have been using medication to relieve headaches regularly (10 to 15 days per month, depending on the medication) for over three months. Usually, these patients have a history of headaches that often get more intense and frequent over time.
The most common type of headaches that lead to MOH are:
- Migraines (65% of cases)
- Tension headaches (27% of cases)
- Mixed or other types of headaches (8% of cases)
This transition from periodic to MOH is usually gradual, with patients noticing that their headaches become stronger and occur more frequently. Also, it’s essential to keep in mind that headache characteristics can change over time. Most people with MOH (90%) use different types of medication to find relief. Frequent morning headaches and neck pain may happen due to withdrawal from the medication overnight or poor sleep quality.
MOH can cause central sensitization, which can make the skin more sensitive and spread the area of the headache. Along with the headache, the person might experience symptoms like a runny nose, tearing, nausea, vomiting, and diarrhea. In most cases, a physical examination will show no neurologic deficits. It’s crucial to get a thorough history and physical examination, noting details like the type and frequency of headaches and medication use, to rule out any other secondary headache syndromes that might need a different treatment plan.
Testing for Medication-Overuse Headache
The diagnosis of medication-overuse headaches (MOH) is primarily based on how often they occur, rather than how severe they feel. There is no need for additional laboratory tests, radiographic scans or other tests unless there are special concerns raised from the patient’s medical history or physical examination.
The International Classification of Headache Disorders -3rd edition (ICHD-3) provides specific criteria for diagnosing MOH. This includes: having headaches on more than half the days in a month, overuse of medication for relieving headaches for over three months, and ensuring that no other diagnosis better explains the situation.
Overuse of medication means regularly taking certain type of drugs more than a specific number of days per month. For instance, drugs such as ergotamines, triptans, opioids, and combination painkillers should be taken 10 or more days per month for more than three months. On the other hand, taking medications like paracetamol, ASA, and Nonsteroidal anti-inflammatory drugs (NSAIDs) for 15 or more days per month for over three months is also considered as overuse. If you’re combining different classes of drugs, again it’s the frequency of use – taken for 10 or more days in a month for over three months – that matters.
Treatment Options for Medication-Overuse Headache
The approach to manage medication overuse headache (MOH) includes educating patients, ensuring proper prophylaxis, halting the overuse of painkillers, and maintaining follow-up appointments to avert a recurrence.
Prevention is key for MOH, a condition regarded as preventable. Therefore, it’s crucial to enlighten patients about how to properly take medication and the dangers of not only side effects, but also the probability of developing chronic headaches from taking excessive medicine. Studies have shown that patient education is beneficial in reducing instances of MOH. In one study, 75% of patients discontinued overusing medication. It’s been established that a tiny fraction (8%) of patients are aware that overuse of all types of headache medicine, even those available over-the-counter, can result in MOH.
Specific techniques can be used to help patients ease off the overused medication hence minimizing MOH.
One method is to replace the overused medicine with a different treatment for symptom relief: Stop the overused medication, start or boost preventive treatment, and use a different symptomatic medication for up to 2 days per week. This is particularly useful for patients more likely to experience drug toxicity from overused medication than withdrawal symptoms. This approach has also been supported by positive outcomes from clinical trials.
Another approach is to continue using the overused medication while starting initial therapy. This is good for patients resistant to stopping the medication and are not at risk of toxicity.
Patients with severe or frequent headaches, who are more likely to get headaches when halting the overused medication and starting symptomatic and preventive therapy, are advised to receive bridge therapy (temporary medication) to manage their withdrawal symptoms and for comfort during this period.
One other strategy is to halt the overused medication before starting preventive therapy: Stop the overused medication for two months prior to starting preventive medication. However, patients may not tolerate this approach therefore, it is generally not recommended.
Another method is to tailor the treatment based on ceasing the specific offending drug. This includes stopping drugs other than opioids, barbiturates, or benzodiazepines and starting or optimizing preventive therapy. Patients can switch from the overused drug to a substitute medication from a different class, but the use of acute medication should be limited to no more than two days per week.
For patients who continue to experience headaches, bridge therapy with a long-acting NSAID (non-steroidal anti-inflammatory drug) or steroid can be added. Discontinuation of opioids, barbiturates, or benzodiazepines can also gradually be done over 2-4 weeks if high dosages have been taken. However, if lower dosages have been ingested, they can be abruptly withdrawn.
What else can Medication-Overuse Headache be?
When a doctor is trying to diagnose a Medication Overuse Headache (MOH), they would consider ruling out other types of chronic headaches. These can be primary headaches, which are not a symptom of another condition, or secondary, which are caused by another health issue. The list includes:
- Migraine
- Tension-type headache
- Cluster headache
- Short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT)
- Hypnic (or sleep) headache
- Nummular (or coin-shaped) headache
- Chronic paroxysmal hemicrania (a severe type of headache occurring mostly in women)
The doctor should also ask the patient if they’ve had any head trauma in the past. If the patient’s past incidents or the physical exam raise any red flags, the doctor may need to run some diagnostic tests to rule out more serious medical or neurological issues. These conditions could include:
- Veinous sinus thrombosis (a blood clot in the brain)
- Subdural hematoma (bleeding between the brain and its outermost protective layer)
- Carbon monoxide poisoning
- Brain tumors
- Hydrocephalus (a buildup of fluid in the brain)
- Idiopathic intracranial hypertension (increased pressure in the brain without a known cause)
Understanding these possibilities help the physicians make an accurate diagnosis.
What to expect with Medication-Overuse Headache
Continually taking too much medication for sudden headaches can lead to chronic headaches and a lower quality of life. The secret to treating Medicine-Overuse Headaches (MOH) is motivating the patient to change their behavior. Studies have shown that more than half of MOH patients can achieve a reduction of at least 50% in their headache frequency if they stop overusing their drugs. Furthermore, 50 to 70% of patients are successful in abstaining from excessive drug use after a year. If a patient can maintain this withdrawal for a year, it generally indicates a good long-term success rate.
However, it’s important to note that there’s a relapse rate of 40 to 50% after six years. Successful drug withdrawal often leads to a better response in preventative treatments, even if there’s little to no improvement in headache frequency. There are several known triggers for relapse, including tension headaches, long-term regular drug intake, a high frequency of acute treatments, lack of improvement after two months of withdrawal, smoking, and alcohol use, and a return to overused drugs.
Patients who overuse ‘Triptan’, a type of drug used for treating migraines, have shown a lower relapse rate, while those using multiple drug therapies have a higher relapse rate. Furthermore, drugs containing codeine, poor sleep quality reported by patients, and high levels of body pain are likely indicators of poor outcomes after a year.
The addition of behavioral therapy to the treatment plan can greatly reduce relapse rates for MOH. In one study, if behavioral therapy was added to the treatment plan, only 12.5% of patients had a relapse of headache after 3 years, compared to 42% of patients who didn’t receive behavioral therapy.
Possible Complications When Diagnosed with Medication-Overuse Headache
Some side effects can happen from taking the medication, including becoming dependent on it and experiencing harmful effects from taking too much. Additionally, using non-steroidal anti-inflammatory drugs (NSAIDs) can lead to bleeding in your upper digestive tract.
- Medication dependence
- Toxicity from the medication
- Bleeding in the upper digestive tract from NSAID use
Preventing Medication-Overuse Headache
People suffering from MOH, or Medication Overuse Headache, can benefit greatly if other health issues they may have, such as mood disorders, obesity, lack of activity or smoking, are also addressed. Ongoing support, including education, check-ups, and behavioral therapy, can also help. One goal should be to increase awareness about MOH among the general public. For instance, a 2014 study showed that 77% of undergraduate students did not know about MOH. After learning about it, 83% of these students believed there should be warnings about MOH on medicine bottles. Additionally, 80% said that they’d take fewer painkillers upon gaining knowledge about MOH.
