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Tromethamine

Medically reviewed by Drugs.com. Last updated on Oct 28, 2020.

Pronunciation

(troe METH a meen)

Index Terms

  • Tris Buffer
  • Tris(hydroxymethyl)aminomethane

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Solution, Intravenous:

Tham: 30 mEq/100 mL (500 mL) [latex free]

Brand Names: U.S.

  • Tham

Pharmacologic Category

  • Alkalinizing Agent, Parenteral

Pharmacology

Acts as a proton acceptor, which combines with hydrogen ions, liberating bicarbonate buffer, to correct acidosis. It buffers both metabolic and respiratory acids, limiting carbon dioxide generation. Also an osmotic diuretic.

Absorption

30% of dose is not ionized.

Excretion

Urine (>75%) within 8 hours.

Use: Labeled Indications

Metabolic acidosis: Correction of metabolic acidosis associated with cardiac bypass surgery or cardiac arrest; to correct acidity of stored blood that is preserved with acid citrate dextrose; metabolic acidosis associated with respiratory distress syndrome in neonates and infants.

Contraindications

Uremia or anuria; chronic respiratory acidosis (neonates); salicylate intoxication (neonates).

Dosing: Adult

Note: Limit dose to amount sufficient to increase blood pH to near normal limits (~7.35) and to correct metabolic acidosis. Retention of tromethamine in patients with impaired kidney function may occur and may lead to metabolic alkalosis. Evaluate blood pH and clinical status during therapy.

Correction of acidity of acid citrate dextrose blood used in cardiac bypass surgery: 15 to 77 mL of 0.3 M solution (500 mg to 2.5 g) added to each 500 mL of acid citrate dextrose (ACD) blood; 62 mL (2g) added to 500 mL of ACD blood is adequate for most adults.

Estimated dose when buffer base deficit is known: IV: tromethamine dose (mL of 0.3 M solution) = body weight (kg) x base deficit (mEq/L) x 1.1.

Metabolic acidosis associated with cardiac arrest:

IV: Initial: 111 to 333 mL of 0.3 M solution (3.6 to 10.8 g); additional amounts may be required to control acidosis after arrest reversed.

Open chest: Intraventricular cavity: 62 to 185 mL of 0.3 M solution (2 to 6 g). Note: Do not inject into cardiac muscle.

Metabolic acidosis associated with cardiac bypass surgery: IV: 500 mL of 0.3 M solution (150 mEq) is adequate for most adults; in severe cases up to 1,000 mL may be needed; average dose: 9 mL/kg (324 mg/kg) of 0.3 M solution; maximum single dose: 500 mg/kg over at least 1 hour; reevaluate blood pH and clinical status to guide repeat dosing.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Note: Dose dependent upon severity and progression of acidosis; doses should be administered slowly to prevent overtreatment. Tromethamine is available as a 0.3 M solution (THAM). Each mL of THAM = 0.3 mmol = 36 mg = 0.3 mEq

Metabolic acidosis: Infants, Children, and Adolescents: IV: Empiric dosage calculation equation based upon base deficit:

Dose (mL) of THAM = body weight (kg) x base deficit (mEq/L) x 1.1*

*Factor of 1.1 accounts for an approximate reduction of 10% in buffering capacity due to the presence of sufficient acetic acid to lower the pH of the 0.3 M solution to approximately 8.6.

Metabolic acidosis with respiratory distress: Infants: IV: Initial: 1 mL/kg for each pH unit below 7.4; additional doses to be determined by changes in PaO2, pH, and pCO2.

Metabolic acidosis with cardiac arrest: Limited data available: Note: Routine use of buffering agents during cardiac arrest not recommended (AHA [Kleinman 2010]):

Infants, Children, and Adolescents: THAM: IV: 1 mL/kg should raise bicarbonate concentration by 1 mEq/L (Fuhrman 2016).

Administration

IV: Correction of metabolic acidosis in cardiac bypass surgery: Administer by slow IV infusion over at least 1 hour (maximum rate: 500 mg/kg over at least 1 hour); rapid administration may result in prolonged hypoglycemia.

Correction of acid citrate dextrose (ACD) blood acidity in cardiac bypass surgery: Add to each 500 mL of ACD blood used to prime the pump-oxygenator.

Correction of metabolic acidosis in cardiac arrest: If chest is open, instill directly into ventricular cavity; do NOT inject into cardiac muscle. If chest is not open, inject into a large peripheral vein. Administer at same time as other standard resuscitative measures.

Vesicant (with IV administration); ensure proper needle or catheter placement prior to and during administration; avoid extravasation.

Extravasation management: If extravasation occurs, stop IV administration immediately and disconnect (leave cannula/needle in place); gently aspirate extravasated solution (do NOT flush the line); remove needle/cannula; elevate extremity.

Storage

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

Drug Interactions

Alpha-/Beta-Agonists (Indirect-Acting): Alkalinizing Agents may increase the serum concentration of Alpha-/Beta-Agonists (Indirect-Acting). Monitor therapy

Amantadine: Alkalinizing Agents may increase the serum concentration of Amantadine. Monitor therapy

Amphetamines: Alkalinizing Agents may decrease the excretion of Amphetamines. Management: Consider alternatives to using amphetamines and alkalinizing agents in combination. If these agents must be used together, patients should be monitored closely for excessive amphetamine effects. Consider therapy modification

Flecainide: Tromethamine may increase the serum concentration of Flecainide. Monitor therapy

Mecamylamine: Alkalinizing Agents may increase the serum concentration of Mecamylamine. Monitor therapy

Memantine: Alkalinizing Agents may increase the serum concentration of Memantine. Monitor therapy

QuiNINE: Alkalinizing Agents may increase the serum concentration of QuiNINE. Monitor therapy

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.

Frequency not defined:

Cardiovascular: Localized phlebitis, venospasm, venous thrombosis

Endocrine & metabolic: Hyperkalemia, hypervolemia, hypoglycemia

Hepatic: Hepatic necrosis (resulted during delivery via umbilical venous catheter)

Local: Injection site infection, local irritation

Respiratory: Pulmonary edema, respiratory depression

Miscellaneous: Fever

Warnings/Precautions

Concerns related to adverse effects:

• Extravasation: Vesicant; ensure proper needle or catheter placement prior to and during administration; avoid extravasation. May cause tissue inflammation, sloughing, and necrosis.

• Hypoglycemia: May cause hypoglycemia with rapid administration or extremely large doses; monitor serum blood glucose during and after therapy.

• Respiratory depression: Large doses may decrease respiratory ventilation due to increased blood pH and reduced CO2; adjust dose so that blood pH is not increased above normal. Monitor closely especially if patient not intubated. In patients with concomitant respiratory acidosis, use only with mechanical ventilation.

Disease-related concerns:

• Renal impairment: Use with caution in patients with renal impairment; possibly decrease excretion of tromethamine; use ECG monitoring and monitor serum potassium.

Other warnings/precautions:

• Duration of therapy: Drug should not be given for a period of >24 hours, unless for a life-threatening situation.

Monitoring Parameters

Serum electrolytes (especially potassium, blood glucose); renal function, urinary output, arterial blood gases, ECG monitoring, fluid status, ventilation rate.

Check infusion site frequently during administration.

Pregnancy Considerations

Animal reproduction studies have not been conducted.

Patient Education

What is this drug used for?

• It is used to treat or prevent acid problems in the blood.

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Low blood sugar like dizziness, headache, fatigue, feeling weak, shaking, fast heartbeat, confusion, increased hunger, or sweating

• High potassium like abnormal heartbeat, confusion, dizziness, passing out, weakness, shortness of breath, or numbness or tingling feeling

• Trouble breathing

• Slow breathing

• Shallow breathing

• Shortness of breath

• Excessive weight gain

• Swelling of arms or legs

• Severe injection site pain, burning, swelling, blisters, or irritation

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

More about tromethamine

Consumer resources

Professional resources

Other brands: Tham

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