Primary headaches are the far larger group, and include tension, migraine, and cluster headaches. They can be treated in two ways – either with preventative treatment, or with rescue treatment once the pain starts. Prevention is of course far preferable, and can be achieved in most patients.
An initial and fundamentally important step in the management of headache is to differentiate those headaches that are the result of other, often serious, conditions ('secondary' headaches) from headaches that are not caused by an underlying disease process ('primary' headaches).
Although symptomatic treatment of pain is also necessary in secondary headaches, it is crucial to treat the underlying cause. In the case of a brain tumour, this may mean surgical excision or a shunt to reduce raised intracranial pressure; antibiotics for bacterial meningitis; and surgical drainage of an intracranial haemorrhage.
The Migraine Generator
In order to understand the treatment rationale for primary headaches, it is necessary to understand the pain-producing mechanism. Current theory recognises the presence of a centre in the brain from which the headaches are triggered. It is generally known as the “migraine generator”.
In headache sufferers, the migraine generator is thought to be more sensitive than in non-headache sufferers. Because of this it discharges more easily, resulting in headache or migraine. Incoming sensory messages from the structures making up the head and neck, terminate in the migraine generator. When there are sufficient incoming messages, the migraine generator fires, and causes a headache.
There are broadly two ways to prevent the headaches. One is to reduce the sensitivity of the migraine centre with medication, and the other is to reduce the number of incoming impulses reaching the migraine generator.
Drugs for headache are either prophylactic or symptomatic.
Prophylactic medications are taken daily and are directed towards preventing the headache from developing in the first place. They are not pain medications.
There are a wide variety of prophylactic medications. Tricyclic antidepressants like amitryptyline are frequently used, and can ease headache even in those patients not clinically depressed. Other medications include several of the anti-epileptic drugs and the calcium channel blockers. Beta-blockers, used to lower blood pressure in other patients, are effective in migraine.
Although prophylactic or preventative medications may sometimes be effective in certain headache or migraine sufferers, the results have generally not been encouraging. There is also the very real problem of side effects, which can be more unpleasant than the headaches.
A large percentage of people who have been prescribed preventive medications stop taking them, either because they are not effective, or because of the unpleasant side effects. For these reasons, prophylactic medication should be reserved for those patients who have not responded to other preventative treatment options.
Symptomatic, abortive or rescue medication
One of the main problems with taking painkillers for headaches is that it often leads to Medication Overuse Headache (MOH). MOH is a problem that occurs in headache sufferers who have to take painkillers on a regular basis – the headaches become more frequent and more severe! Because of this, the patient increases the dosage and takes the drugs more often, and a vicious circle is set up, making the headaches worse and worse.
This can happen with any of the painkillers, but is far more likely to occur when the medication contains more than one drug, and especially if it contains caffeine, ergotomine or codeine.
When the three are combined in one pill, there is an even greater likelihood of MOH developing. It is important that you examine the box or insert of the medications you use, and check what they contain. And remember – MOH can occur with prescription or over-the-counter headache medication.
If you suffer from headaches, the answer is not to rely on medication or painkillers. The correct way to deal with the problem is to have a proper diagnosis of the causes of the headache. If the causes can be successfully treated, the headaches no longer occur, and it is no longer necessary to rely on potentially harmful “rescue” medication.
If you have not been able to have the proper diagnosis and treatment yet, and are forced to use medication, then symptomatic or “abortive” medications are the pain medications that should be used. These are drugs are designed to stop the headache once it has started.
Once a headache has taken hold, any of a wide selection of abortive medications is used. These include simple analgesics like paracetamol and aspirin, anti-inflammatories and muscle relaxants.
Narcotic analgesics may be necessary for the most severe headaches, but they are best limited to once-off usage, and should not be prescribed longer-term, as they are habit-forming. Often a trial-and-error approach is necessary to match an individual patient with the most suitable medication.
Migraine is often associated with intense nausea, and an anti-emetic (a drug that treats nausea and vomiting) may bring a measure of relief.
Medications that act on the calibre of blood vessels have an important place in migraine therapy – the ergot drugs of old have largely been replaced by the newer “triptan” medications like sumatriptan, which has oral, subcutaneous and intranasal forms. Unusual primary headaches like cluster may respond to breathing oxygen.
It should be mentioned that all headache medications have side-effects, and so should be used judiciously.
Causes of headaches
Reviewed by Dr Elliot Shevel, BDS, Dip MFOS, MB, BCh, Maxillo-facial and Oral Surgeon and Medical Director, The Headache Clinic, Johannesburg and Cape Town, February 2015.
Previously reviewed by Dr Andrew Rose-Innes, MD, Department of Neurology, Yale University School of Medicine, New Haven