Preventive medicines are used to avoid severe or
chronic headaches, such as migraines or cluster headaches. They are not usually
used to treat headaches after they begin.
Preventive medicines relax blood vessels. Some
headaches may be caused by narrowing or tightening of blood vessels.
Examples of preventive medicines are
beta-blockers, calcium channel blockers, antidepressants, and
anticonvulsants.
In order for these medicines to work, you will need to
take them daily even when you do not have a headache. You may have to take them
daily for only a few months.