Tromethamine

Tham Solution (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. Tham Solution 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. It is well known that ACD blood is acidic and becomes more acidic on storage. Tromethamine effectively corrects this acidity. Tham Solution may be added directly to the blood used to prime the pump-oxygenator. When ACD blood is brought to a normal pH range the patient is spared an initial acid load.

Tham Solution (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). Pretreatment and subsequent determinations of blood values (e.g. pH, PCO 2, PO 2, glucose and electrolytes) and urinary output should be made as necessary to monitor dosage and progress of treatment.

Tham Solution (tromethamine injection) is contraindicated in uremia and anuria. In neonates it is also contraindicated in chronic respiratory acidosis and salicylate intoxication.

Large doses of Tham Solution may depress ventilation, as a result of increased blood pH and reduced CO 2 concentration. Thus, dosage should be adjusted so that blood pH is not allowed to increase above normal. In situations in which respiratory acidosis may be present concomitantly with metabolic acidosis, the drug may be used with mechanical assistance to ventilation. Care must be exercised to prevent perivascular infiltration since this can cause inflammation, necrosis and sloughing of tissue. Venospasm and intravenous thrombosis, which may occur during infusion, can be minimized by insuring that the injection needle is well within the largest available vein and that solutions are slowly infused. Intravenous catheters are recommended. If perivascular infiltration occurs, institute appropriate countermeasures.

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. Local tissue damage and subsequent sloughing may occur if extravasation occurs. Chemical phlebitis and venospasm also have been reported. Hematologic: Transient depression of blood glucose may occur. Hepatic: Infusion via low-lying umbilical venous catheters has been associated with hepatocellular necrosis.

Store at 20 to 25°C (68 to 77°F). Protect from freezing.