ATI PHARMACOLOGY REMEDIATION 2019 / 2020 / 2021 Reliable Guide 1. Feverfew ∙ Can block platelet aggregation. ∙ Can block a factor that causes migraines. ∙ Can decrease the number and severity of migraine headaches (does not treat an existing migraine Adverse effects and precautions ∙ Mild GI manifestations ∙ Post feverfew syndrome can occur when abruptly discontinued, causing agitation, tiredness, inability to sleep, headache, and joint discomfort. ∙ Allergic reacti...