Astanga Hrudaya
न सिध्यत्यौषधं यस्य नास्ति तस्य चिकित्सितम् । भवेद्यस्यौषधेऽन्ने वा कल्प्यमाने विपर्ययः ॥ १२५ ॥
He, in whom the medicine which is well known, found effective many times and administered according to proper procedures still does not prove effective, there is no other treatment for him. Fatal signs based on sudden changes occurring in the medicines and foods for no obvious reasons: Either the medicine or food, prepared for a person, under going change into the opposite, in their colour, smell etc
english translation
na sidhyatyauSadhaM yasya nAsti tasya cikitsitam । bhavedyasyauSadhe'nne vA kalpyamAne viparyayaH ॥ 125 ॥
hk transliteration by Sanscript