Charak Samhita
रसायनविधिभ्रंशाज्जायेरन् व्याधयो यदि। यथास्वमौषधं तेषां कार्यं मुक्त्वा रसायनम् ॥२९॥
If during the treatment some complications arise due to faulty methods, better treatment is planned after discontinuing the initial course of Rasayana therapy.
english translation
rasAyanavidhibhraMzAjjAyeran vyAdhayo yadi। yathAsvamauSadhaM teSAM kAryaM muktvA rasAyanam ॥29॥
hk transliteration by Sanscript