What Is An Analgesic Rebound Headache?

A group of patients with daily or near-daily headaches can’t function effectively or practise their routine daily life without taking analgesics (painkillers) regularly and seeking medical advice as they hope to be prescribed more potent analgesics. This is identified as an analgesic rebound headache or medication overuse headache (MOH) due to misuse of medications in treating their symptoms. These patients experience increasingly frequent headaches with time, which become unresponsive to both abortive and prophylactic medication.^1,2

Several questions arise here. Are these patients overtly seeking drugs? Is it really that without their daily use of medications, a headache would be an obstacle to functioning and practising their daily life? Or does the medication itself control the headache? What are the therapeutic plans and optimal options for this type of chronic headache?³

Classification of chronic headache

According to the International Headache Society (IHS), the common types of diagnosed chronic primary headache disorders are migraine, tension-type, and cluster headaches. 

Chronic migraine is diagnosed by certain episodic headache criteria occurring more than 15 days per month for at least 3 months without any evidence of medication overuse. However, tension-type continues for more than 3 months without evidence of medication overuse.⁵

If the specialist suspects medication overuse, the medication should be withdrawn for at least 2 months to confirm the diagnosis of chronic migraine or tension-type headache.⁶ A patient could have both chronic migraine and tension-type, but IHS considers this type of chronic headache uncommon and of rare occurrence. Moreover, IHS updates mentioned that the diagnostic criteria depend on the patient's history in differentiating chronic migraine and chronic tension-type headaches.

Cluster headache is defined by cluster attacks for more than 1 year in the absence of a remission phase for a period longer than one month. Medication overuse is not a factor that triggers cluster headaches. ³

Interestingly, the analgesic rebound headache plays an important role in the transformation of an episodic headache into a chronic headache disorder. 

Clinical features

Clinically, analgesic rebound headache could be of unclear distinctive features as it appears as a transformed tension headache or migraine thus it becomes hard to distinguish between these types and rebound headaches.^1,4

However, several clinical features are useful to differentiate the occurrence of rebound headaches in patients with primary headache disorders. The clinical characteristics are the following:^2,7

• Headaches occur in patients with a primary headache disorder, which means they occur without a clear underlying cause, systemic disease, or trauma.
• Patients use excessive quantities of medication frequently
• Headaches are daily or nearly daily
• Light activities, exercise, or efforts can trigger a headache. Thus, there is a low threshold for head pain.
• The headache itself varies in terms of location, severity, and type from time to time.
• Headaches are linked to nausea, other gastrointestinal symptoms, fatigue, anxiety, memory problems, difficulties in concentration, and depression.
• Patients who are consuming excessive quantities of ergot derivatives may experience tachycardia, low pulse, hypertension, cold extremities, and depression.
• Predictable early morning headaches between 2:00 am to 5:00 am are recurrent, particularly in patients who use high quantities of analgesic, caffeine, sedative, or ergotamine combinations.
• Barbiturate-containing analgesics, such as butalbital with caffeine and acetaminophen or with caffeine and aspirin, result in rebound headaches accompanied by awakening due to rapid eye movement (REM) suppression.
• Discontinuation of the medications results in spontaneous improvement of headache.
• Observation of withdrawal symptoms once the medication is taken off suddenly
• Prophylactic medications are relatively low efficacy, and patients consume excessive quantities of immediate relief medication.

Differential diagnosis

Diagnosis of rebound headache could be confusing due to some common clinical features of the underlying primary headache types. Thus it is of high significance to obtain an accurate and targeted medical history, including certain questions about over-the-counter medications. Moreover, any changes in the rhythmicity of a previously stable headache should be taken seriously, not every change in a pattern of a stable headache means medication overuse. In these cases, the patient needs a careful reevaluation.¹

Testing

There is no specific test for analgesic rebound headache. Testing is used mainly to determine if there are any occult pathologic mechanisms or other disorders that mimic migraines or tension-type headaches.⁷ Patients who experience a recent onset of chronic frequent headaches are first thought to have rebound headaches. This can be confusing and tricky; however, these patients should undergo magnetic resonance imaging (MRI) to rule out cervical spine symptoms or any other pathology. Moreover, MRI should be considered in migraine or tension-type headache patients who have a complaint of recent changes in headache symptoms.¹

Laboratory tests conducted in case of analgesic rebound headache are in question. Screening laboratory tests include blood tests like: 

• Complete blood count
• Automated blood chemistry
• Erythrocyte sedimentation rate

Complications and pitfalls

Patients who overuse medications, including opioids, butalbital, and ergotamines develop chronic dependence and an increase in tolerance (physical dependence) due to prolonged abuse of these drugs. This results in negative consequences that can be life-threatening if abrupt cessation occurs. Thus, the physical dependence on these medications should be treated carefully, it can’t be done just in one step, most of the patients require an inpatient tapering plan, decreasing the dose of the medication gradually,  in a monitored and well-controlled setting.

Patterns of medication consumption in patients with analgesic rebound

Many patients develop a fear of pain and headache attack recurrence, which drives them to consume more analgesics. Prescription and nonprescription medications are used simultaneously. The reasons for daily medication intake given by patients were analysed as follows:

• Analgesic consumption under medical supervision when needed
• Failure to cope with the pain
• Fear of pain if a drug is not taken
• Developing pain recurrence soon after medication intake
• The belief there is no other cure
• Ability of the patient to function well during the work after analgesic consumption
• To overcome stress anxiety and reduce tension
• Sleeping aid

It should be noted that some patients gave a combination of reasons for daily medication consumption. Behavioural aspects are important as relief of pain causes changes in the mood produced by stimulants or barbiturates containing medications, resulting in excessive consumption of immediate relief medications.²

Withdrawal symptoms on discontinuation

An increase in headache pain frequency with a decrease in analgesic efficacy develops over time. Withdrawal symptoms are very prominent including:

• Fatigue
• Insomnia
• Increased headache
• Diarrhoea 
• Occasional seizures, particularly in those who consume excessive amounts of butalbital-containing analgesics²

Treatment and management 

The first step in the treatment of analgesic rebound headache relies mainly on discontinuation of the overused or abused drugs, followed by the ability of the patient to complete this abstention for at least 3 months.⁸

The addition of prophylactic treatment in some patients who suffer from analgesic rebound headaches could be beneficial (e.g., propranolol in migraine), and it may reduce the incidence of headaches. 

Care and caution should be considered in patients who are on specific medications such as barbiturates and/or opioids, it is important to avoid abrupt discontinuation due to their serious side effects, including acute abstinence syndrome and seizures. In such cases, tapering the dose of this type of medication is necessary and should be monitored with caution as the patient may require hospitalisation in a specialised headache unit.

However, if outpatient treatment is being planned, the following points should be clearly explained to the patient:

• The headache and relevant symptoms will get worse before they get better
• Use of offending medications, even in low consumption, will result in continued analgesic rebound headaches.
• The patient shouldn’t self-refer and use over-the-counter medications.
• The overuse of opioids or combination medications containing butalbital or ergotamine can result in physical dependence. Thus, the discontinuation of such drugs should be followed up carefully by a physician due to their significant withdrawal symptoms.¹

Concomitant behavioural therapy

Behavioural intervention plans are essential to ensure the patient is making progress, it includes the following:

• Individual behavioural counselling
• Dietary instructions
• Family therapy
• Physical exercise
• Physical therapy by applying heat, massage, and other techniques to neck muscles may help partially in improving muscle strength and posture ²

Education

Adequate instruction about the nature of analgesic rebound headaches should be emphasised. The patient should be guided about the fact that this disorder is of neurochemical and physiologic mechanisms which produce the headache. They also have to be aware of the effect of anxiety, stress, and depression on the frequency of the headache. These behavioural factors make the headache more severe and hard to manage.²

Psychiatric referral

Analgesic rebound headaches are not a primary psychiatric disorder; however, it is important to consider its comorbidities. The consultation by a psychiatrist should be in combination with the major medical treatment that the neurologist prescribes. Thus, psychiatric treatment should be used only as an adjunct in the overall management.²

Summary

Analgesic rebound headache, also known as medication-overuse headache (MOH), is caused by excessive consumption of painkiller medications such as acetaminophen, NSAID, aspirin etc. The long-term use of these medications contributes to rebound headaches, and the intensity and frequency of headaches increase over time. Medication overuse of headaches has a significant role in the transformation of episodic headaches to chronic headache disorders such as migraine and tension-type. 

Medication overuse of headache can be a competitive clinical syndrome to treat and manage, it may be easier to prevent it rather than treat it.  Patients who are having chronic headaches associated with medication overuse should be advised to discontinue the potentially offending medication for at least 2 months. 

Patients who are on opioids or combination medications containing barbiturates must be followed up by a specialist and be under medical supervision, as these medications cause physical dependence and require a certain tapering therapeutic plan to avoid withdrawal symptoms. Moreover, providing an effective management plan in addition to the therapeutic one is essential, including psychological consultation, education, family support, and certain lifestyle changes.