Drugs used to help stop individual attacks are called abortive agents or acute treatments. The pain of CH builds up so quickly and to such an excruciating peak that most drugs that are designed to be 'swallowed' do not work quickly enough. Medications taken by mouth have to be absorbed by the gut before they start to work, too long for a CH patient to have to endure the pain.
The most effective abortive agents are those that are either administered through the lungs or nose, or by means of injection: either beneath the skin, through the muscle, or into a vein.
The most successful abortive treatment of a cluster attack is a self-administered injection, just beneath the skin, of a drug called sumatriptan (Imigran/Imitrex). It tends to work very quickly amongst a high proportion of sufferers. In CH, unlike in migraine, injecting sumatriptan beneath the skin can be done twice a day, amongst most sufferers, without the risk of the pain reoccurring after the drug has worn off (a rebound headache).
However, sumatriptan is relatively expensive, and accordingly, many GPs and neurologists are sometimes reluctant to prescribe sufferers with this drug. It is generally felt that given the extreme nature of CH, and the excruciating pain involved, that it is unethical for this drug not to be used because of its high cost. Further, since subcutaneous sumatriptan [injections] and nasal sprays are the first line abortive for cluster headache, listed in the BNF - British National Formulary - [GPs prescribing bible of NHS licensed medications], the treatment should not be withheld on grounds of cost.
Sumatriptan can also be inhaled through the nose using a nasal spray, but it is much less effective than injecting beneath the skin. There is no definitive evidence that sumatriptan works for CH in tablet form. 100mg tablets taken three times daily do not prevent an attack and should not therefore be used as a preventative measure. Zolmitriptan taken in 5mg tablet form does help the pain in some sufferers of ECH but not in CCH. However, the effectiveness is modest and is not as effective or as fast acting as oxygen therapy (see below) or sumatriptan injected beneath the skin.
Breathing in pure oxygen at a rate of between 7 to 15 litres per minute is relatively fast acting in providing pain relief amongst most sufferers. It should be inhaled continuously for 15-20 minutes using a non-breathing mask i.e., one without holes. The masks are provided by your oxygen supplier. As soon as you know an attack is starting turn the oxygen on to 15 litres per minute and then after a few minutes turn it down to around 6 to 8 litres per minute, sufficient to keep the little reservoir bag inflated. Stay on the oxygen for a good five to ten minutes after the attack has gone. In England and Wales GPs can prescribe oxygen; in Scotland and Northern Ireland you need to see a consultant or respiratory nurse before oxygen can be prescribed. A new form of oxygen, ultra-high flow oxygen is proving very effective and is gradually being rolled out across the oxygen regions in England and Wales.
Lignocaine in liquid form can be given as either nose drops or nasal spray, deep in the nostril on the painful side. This can bring mild to moderate relief in some sufferers though only a few experience complete pain relief. This drug, therefore, is very rarely useful on its own but can be helpful when taken with other preventative and abortive drugs.
Recently trialled hand-held electronic device which emits a pulse when applied to the vagal nerve in the neck.
Analgesics are drugs that are used to relieve pain in normal circumstances. These include opiates - derived from the opium poppy, such as morphine etc. - and other non-steroidal anti-inflammatory drugs such as aspirin, ibuprofen, and indomethacin. None of these are effective as an abortive drug in CH attacks.