Urinary Alkalinization : Indication & Protocol

• Urine alkalinization is a treatment regimen that increases poison elimination by the administration of intravenous sodium bicarbonate to produce urine with a pH 7.5.
• Urine alkalinization is also indicated in various intoxications such as with salicylates and phenobarbital, as well as during methotrexate treatment and exposure to uranyl compounds, in which the toxic substance is more soluble in relatively alkaline urine.
• It may be used for renal protection in cases of rhabdomyolysis, crush injuries, and tumor lysis syndrome , although this indication is becoming secondary to good hydration over the last years, excluding the first hours after injury.

Indication	Protocol	Reference
Urinary alkalinization	Oral : 14mEq (4g) , then 12-24mEq evert 4 hours ; dose shoyld be itrated up to desired urine pH; doses up to 16g/day  (200mEq) in patient less 60 years and g/day in >60 years	Lexicomp
	Parenteral: 50 to 150 mEq sodium bicarbonate diluted in 1 L of D5W to be intravenously infused at a rate of 1 to 1.5 L/hour. Oral: 325 to 2000 mg orally 1 to 4 times a day. One gram provides 11.9 mEq (mmoL) each of sodium and bicarbonate. If the increase in urinary pH is inadequate, increasing the sodium bicarbonate in solution to 100 to 150 mEq/L may result in further alkalinization of the urine.	Drug.com
Elimination of poisons  (herbicides, chlorproparmide, salicylate, diflunisal, fluoride, methotrexate, barbiturates, sulphonamides)	IV bolus 1-2mEq/kg of 8.4% sodium bicarbonate, followed by continuous infusion of sodium bicarbonate. Continuous infusion is mixed by placing 150mEq of sodium bicarbonate into 1L of 5% dextrose	Uptodate
Methotrexate elimination	IV D5W with 100 to 150 mEq of sodium bicarbonate per liter, administered by continuous infusion at 125 to 150 mL/hour Alternative 50 mL of D5W containing sodium bicarbonate 1 mEq/kg can be infused IV over 30 minutes every four or six hours. Oral sodium bicarbonate can also be given starting with two x 650 mg tablets, and increased up to five tablets every two to four hours.	Uptodate

Possible Complications

• Severe alkalemia – shift of blood pH towards alkalinity
• Hypokalemia
• Hypocalcemia
• Coronary / cerebral vasoconstriction

Reference :

1.  Lexicomp
2.  Uptodate
3. https://www.eapcct.org/publicfile.php?folder=congress&file=PS_UrineAlkalinization.pdf
4.  Efficacy of urine alkalinization by oral administration of sodium bicarbonate: a prospective open-label trial.  Retrieved from http://www.sciencedirect.com