Abu Wa'il narrated: A man among us fell ill, and 'sakar' was prescribed for him. So we came to Sayyiduna Abdullah (may Allah be pleased with him) and asked him, and he said: "Allah, the Mighty and Majestic, has not placed your cure in what He has made unlawful for you."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9681