罂粟碱（英语：Papaverine）是一种鸦片生物碱解痉药，主要用于治疗内脏痉挛、血管痉挛（特别是涉及到心脏与大脑的血管）并间或用于勃起功能障碍。尽管它存在于罂粟之中，罂粟碱在结构与药理学作用上都与镇痛（吗啡相关）鸦片生物碱（鸦片类药物）有区别。

Papaverine /pəˈpævəriːn/ (Latin papaver, "poppy") is an opium alkaloid antispasmodic drug, used primarily in the treatment of visceral spasm, vasospasm (especially those involving the heart and the brain), and occasionally in the treatment of erectile dysfunction. While it is found in the opium poppy, papaverine differs in both structure and pharmacological action from the analgesic (morphine-related) opium alkaloids (opiates).