What is the preferred solution for Nitroglycerin (NTG) infusion, 5% dextrose (5D) or normal saline (NS)?

Nitroglycerin Infusion Diluent: Both 5% Dextrose and Normal Saline Are Acceptable

According to FDA labeling, nitroglycerin injection must be diluted in either 5% dextrose (D5W) or 0.9% sodium chloride (normal saline) prior to infusion—both solutions are equally acceptable and the choice depends on patient-specific fluid requirements. 1

FDA-Approved Diluent Options

Both diluents are explicitly approved by the FDA for nitroglycerin infusion preparation:

• 5% Dextrose Injection (D5W) 1
• 0.9% Sodium Chloride Injection (Normal Saline) 1

The FDA label states that nitroglycerin "MUST BE DILUTED IN DEXTROSE (5%) INJECTION OR SODIUM CHLORIDE (0.9%) INJECTION PRIOR TO ITS INFUSION" and explicitly notes that either solution is appropriate. 1

Standard Dilution Protocol

For initial preparation, aseptically transfer 50 mg of nitroglycerin into a 500 mL glass bottle of either D5W or normal saline, yielding a final concentration of 100 mcg/mL. 1

Alternatively, diluting 5 mg nitroglycerin into 100 mL of either diluent yields a concentration of 50 mcg/mL. 1

Factors Guiding Diluent Selection

Choose based on patient fluid requirements and clinical context:

• Use D5W in patients who are euvolemic or hypernatremic, or when avoiding additional sodium load is desirable 1
• Use normal saline in patients who are hypovolemic, hyponatremic, or diabetic (to avoid dextrose administration) 1

The selection should consider the expected duration of infusion and the patient's overall fluid management plan. 1

Critical Administration Requirements

Use non-absorbing (non-PVC) tubing regardless of diluent choice. The type of administration set has a far greater impact on drug delivery than the choice of diluent. 2, 3

Polyvinyl chloride (PVC) tubing causes significant nitroglycerin adsorption, with relative drug availability as low as 41.5% at slower infusion rates, whereas polyethylene tubing delivers 96-97% of the labeled concentration. 4

When using non-absorbing tubing, initiate at 5-10 mcg/min and titrate by 10 mcg/min every 3-5 minutes until symptom relief or blood pressure response. 2, 3, 1

Common Pitfall to Avoid

Never mix nitroglycerin with other drugs in the same solution. The FDA label explicitly states "NITROGLYCERIN INJECTION SHOULD NOT BE MIXED WITH OTHER DRUGS." 1

When changing concentrations, always flush or replace the infusion set before administering the new concentration to avoid unpredictable delays in drug delivery. 1