What should you know about lithium and cluster headaches?

Cluster headaches cause repeated bouts of severe pain, often around one eye, with symptoms such as tearing, a blocked or runny nostril and restlessness. Lithium can be used as a preventive medicine in selected cases, especially when attacks follow a prolonged pattern. It is not a quick painkiller for an attack and does not suit everyone. The dose must be individualised because the safe range is narrow and the body clears lithium through the kidneys.

Take lithium at the same times each day and do not alter or stop it suddenly without medical advice. Keep fluid and salt intake reasonably steady, and ask for advice during vomiting, diarrhoea, heavy sweating or an illness that makes drinking difficult. Tell every clinician and pharmacist that you take lithium before starting another medicine. Monitoring may include blood lithium levels, kidney function and thyroid checks, with extra review after dose changes or illness.

Seek urgent help for severe shaking, worsening weakness, confusion, unsteady walking, slurred speech, repeated vomiting, extreme drowsiness or new vision changes, as these can signal lithium toxicity. Emergency care is needed for a sudden explosive headache, new weakness, fainting, seizure or a headache unlike your usual attacks. Do not take an extra dose to end a cluster attack unless your clinician has specifically instructed you.

Ask whether lithium is appropriate for your attack pattern, which acute treatment to use, when blood tests are due and which medicines or supplements can interact. Discuss pregnancy plans, kidney or thyroid conditions and a written plan for illness or missed doses.