Overview
DESCRIPTION Tromethamine Injection is a sterile, nonpyrogenic 0.3 M solution of tromethamine, adjusted to a pH of approximately 8.6 with glacial acetic acid. It is administered by intravenous injection, by addition to ACD blood for priming cardiac bypass equipment and by injection into the ventricular cavity during cardiac arrest. Each 100 mL contains tromethamine 3.
Mechanism of Action
CLINICAL PHARMACOLOGY When administered intravenously as a 0.3 M solution, tromethamine act as a proton acceptor and prevents or corrects acidosis by actively binding hydrogen ions (H + ). It binds not only cations of fixed or metabolic acids, but also hydrogen ions of carbonic acid, thus increasing bicarbonate anion (HCO 3 – ). Tromethamine also acts as an osmotic diuretic, increasing urine flow, urinary pH, and excretion of fixed acids, carbon dioxide and electrolytes. A significant fraction of tromethamine (30% at pH 7.40) is not ionized and therefore is capable of reaching equilibrium in total body water. This portion may penetrate cells and may neutralize acidic ions of the intracellular fluid.
Indications
- INDICATIONS AND USAGE Tromethamine Injection is indicated for the prevention and correction of metabolic acidosis. In the following conditions it may help to sustain vital functions and thus provide time for treatment of the primary disease: Metabolic Acidosis Associated with Cardiac Bypass Surgery. Tromethamine Injection has been found to be primarily beneficial in correcting metabolic acidosis which may occur during or immediately following cardiac bypass surgical procedures. Correction of Acidity of ACD Blood in Cardiac Bypass Surgery.
Common Doses
- 385 mL
- 13.9 g
- 9.0 mL
- 324 mg
Dosage
DOSAGE AND ADMINISTRATION Tromethamine Injection is administered by slow intravenous infusion, by addition to pump-oxygenator ACD blood or other priming fluid or by injection into the ventricular cavity during cardiac arrest. For infusion by peripheral vein, a large needle should be used in the largest antecubital vein or an indwelling catheter placed in a large vein of an elevated limb to minimize chemical irritation of the alkaline solution during infusion. Catheters are recommended. Dosage and rate of administration should be carefully supervised to avoid overtreatment (alkalosis).
Contraindications
- CONTRAINDICATIONS Tromethamine Injection is contraindicated in uremia and anuria. In neonates it is also contraindicated in chronic respiratory acidosis and salicylate intoxication.
Side Effects
- ADVERSE REACTIONS Generally, side effects have been infrequent. Respiratory: Although the incidence of ventilatory depression is low, it is important to keep in mind that such depression may occur. Respiratory depression may be more likely to occur in patients who have chronic hypoventilation or those who have been treated with drugs which depress respiration. In patients with associated respiratory acidosis, tromethamine should be administered with mechanical assistance to ventilation. Vascular: Extreme care should be taken to avoid perivascular infiltration.
Interactions
- No major interactions listed on the FDA label. Always consult a healthcare professional.