Compatibility and stability of tramadol and dexamethasone in solution and its use in terminally ill patients.
BACKGROUND
Delivery of drug admixtures by continuous subcutaneous infusion is common practice in palliative medicine, but analytical confirmation of their compatibility and stability is not always available.


OBJECTIVE
To study the compatibility and stability of tramadol hydrochloride and dexamethasone sodium phosphate combined in solution and to report on its use in terminally ill patients.


METHODS
Twelve different solutions containing tramadol hydrochloride (8.33-33.33 mg/mL) and dexamethasone sodium phosphate (0.33-3.33 mg/mL) were prepared in saline and stored in polypropylene syringes for 5 days (25 degrees C). Analysis was performed on days 1, 3 and 5 days with simultaneous determination by HPLC. pH was measured at 0 and 5 days. Clinical performance was assessed retrospectively in six terminal-ill oncology patients.


RESULTS
Maximum losses of 7% and 6% were observed for tramadol and dexamethasone. Pain was completely controlled in four patients. Local tolerance resulted in haematoma in three patients, which resolved by switching to a butterfly insertion site.


CONCLUSIONS
Tramadol hydrochloride (100-400 mg/day) and dexamethasone sodium phosphate (4-40 mg/day) are stable for at least 5 days when combined in saline and stored at 25 degrees C. These results are only valid for the type of syringes and the specific commercial preparations tested.
Negro
S
S
School of Pharmacy, University Complutense, Madrid, Spain. soneal@farm.ucm.es
Salama
A
A
Sánchez
Y
Y
Azuara
M L
ML
Barcia
E
E
D000368:Aged; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000737:chemistry* / Q000627:therapeutic use; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000737:chemistry* / Q000627:therapeutic use; D003907:Dexamethasone / Q000008:administration & dosage / Q000737:chemistry* / Q000627:therapeutic use; D004338:Drug Combinations; D004339:Drug Compounding; D004355:Drug Stability; D004356:Drug Storage; D006801:Humans; D007279:Injections, Subcutaneous; D009369:Neoplasms / Q000150:complications / Q000188:drug therapy; D010146:Pain / Q000188:drug therapy / Q000209:etiology; D010166:Palliative Care; D019999:Pharmaceutical Solutions; D012189:Retrospective Studies; D019452:Terminally Ill; D014147:Tramadol / Q000008:administration & dosage / Q000737:chemistry* / Q000627:therapeutic use
D000701:Analgesics, Opioid; D000893:Anti-Inflammatory Agents; D004338:Drug Combinations; D019999:Pharmaceutical Solutions; D014147:Tramadol; D003907:Dexamethasone