There are various sampling methods. The one chosen will depend on a number of factors (such as time, money etc.). 1. Random Sampling Everyone in the entire target population has an equal chance of being selected. This is similar to the national lottery.
Various types of medications have been evaluated for migraine prophylaxis, including beta blockers, antidepressants, anticonvulsants, nonsteroidal anti-inflammatory drugs (NSAIDs), angiotensin blockade agents, and calcium channel blockers.
Unlike triptans and pain relievers, preventive medications are usually taken every day to prevent the onset of a migraine. Two groups of medications approved for this purpose, that are often used to treat other medical conditions, have been found to be beneficial for some migraine sufferers as well. These medications are antidepressants and anticonvulsants.