PT  - JOURNAL ARTICLE
AU  - Samy A Alsirafy
AU  - Saad H Alabdullateef
AU  - Ashraf M Elyamany
AU  - Amneh D Hassan
AU  - Mohammed Almashiakhi
TI  - Transdermal fentanyl to parenteral morphine route switch and drug rotation in refractory cancer cachexia
AID  - 10.1136/bmjspcare-2019-001935
DP  - 2019 Sep 06
TA  - BMJ Supportive & Palliative Care
PG  - bmjspcare-2019-001935
4099  - http://spcare.bmj.com/content/early/2019/09/05/bmjspcare-2019-001935.short
4100  - http://spcare.bmj.com/content/early/2019/09/05/bmjspcare-2019-001935.full
AB  - It is recommended not to use transdermal fentanyl (Fe) patches (TFP) in cancer cachexia but TFP may be the only available option for pain. Limited evidence suggests lower Fe absorption from TFP in cachexia. We describe a case of metastatic breast cancer with refractory cachexia. Her pain was uncontrolled on TFP and was route switched and drug rotated to intravenous morphine (M). We were conservative and did not use the 1:100 TFP to oral M conversion ratio. Assuming opioid needs were similar before and after switch/rotation, the suitable conversion ratio in this case was about 1:25. Absent clear guidelines on converting from TFP in cachexia, it is better to avoid TFP. When essential to use TFP in cachexia, caution should be taken when switching from TFP to avoid overdose.