Cluster headaches are considered to cause the worst pain imaginable. We have a variety of medications – both acute and preventive – that help relieve the pain of cluster headaches. For some, none of these treatments work and we do need additional medications. Ketamine could be one such drug.
Ketamine has been in use for over 50 years. Its main indication is intravenous anesthesia. Recently, the FDA approved ketamine nasal spray for depression. It is also being widely used intravenously and by mouth for depression, chronic pain, and migraine headaches. A group of researchers at the Danish Headache Center in Glostrup, Denmark tested the efficacy of ketamine nasal spray for the acute treatment of cluster headaches.
Anja Petersen and her colleagues selected 20 cluster patients whose attacks did not respond sufficiently well to sumatriptan or oxygen – the two most effective acute therapies for cluster headaches. Patients treated a single cluster attack with 15 mg of intranasal ketamine. They could repeat this dose every 6 minutes, for up to 5 times. Four patients took another medication after 15 minutes. Of the 16 remaining ones, 11 had a drop in pain severity by an average of four points, to four or lower on a one to 10 scale. Half of the patients preferred ketamine to oxygen and/or sumatriptan injection. No patient had any serious side effects from ketamine during the trial.
Ketamine nasal spray that is approved for depression is a more potent version of ketamine called esketamine (Spravato). It is a patented and branded product and it is very expensive. Ketamine itself, however, is a cheap drug. A compounding pharmacy can prepare a nasal spray for as little as $60 for a month supply. Most insurers do not cover compounded drugs, so you’d have to pay for it.
