A nasogastric (NG) tube or gastrostomy tube allows direct instillation of medication into the gastrointestinal (GI) system of patients who can't ingest the drug orally. Before instilling the drug, you must check the patency and positioning of the tube. Oily medications and enteric-coated or sustained-release tablets (sublingual, chewable) or capsules are contraindicated for instillation through an NG tube.
Patient's medication record and chart 
prescribed medication towel or linen-saver pad 50- or 60-mL piston-type catheter-tip syringe feeding tubing two 4'' × 4'' gauze pads stethoscope gloves diluent cup for mixing medication and fluid spoon 50 mL of water gastrostomy tube and funnel, if needed optional: mortar and pestle, clamp.
For maximum control of suction, use a piston syringe instead of a bulb syringe. The liquid for diluting the medication can be juice, water, or a nutritional supplement.
Gather all necessary equipment at the bedside. Liquids should be at room temperature so abdominal cramping doesn't occur.
Verify the order on the patient's medication record by checking it against the doctor's order, perform hand hygiene, and don gloves. Check the label on the medication before preparing it for administration.
Liquid or crushed
Request liquid forms of medications, if available. However, if the prescribed medication is in tablet form, crush the tablets to dilute them with at least 30 mL of water unless otherwise specified and bring the medication and equipment to the patient's bedside. All liquids should be at room temperature. Cold liquids instilled in the enteral tube can cause abdominal cramping.
Explain the procedure to the patient, provide privacy, and confirm the patient's identity using two patient identifiers.
Unpin the tube from the patient's gown and drape his chest with a towel or linen-saver pad.
Elevate the head of the bed from 30 degrees to Fowler's position, as tolerated, to reduce the risk of aspiration.
After unclamping the tube, confirm placement of the NG tube. (See “Nasogastric tube care,” in chapter 8,.)
After you've established that the tube is patent and in the correct position, clamp the tube, detach the syringe, and lay the end of the tube on the 4'' × 4'' gauze pad.
Mix and stir
Mix the crushed tablets or liquid medication with water unless otherwise specified. If the medication is in capsule form, open the capsules and empty their contents into the water. Pour liquid medications directly into the water. Stir well with the spoon. (If the medication was in tablet form, make sure the particles are small enough to pass through the eyes at the distal end of the tube.)
Reattach the syringe, without the piston, to the end of the tube and open the clamp.
Deliver the medication slowly and steadily. (See Giving medications through an NG tube.)
How goes the flow?
If the medication flows smoothly, slowly add more until the entire dose has been given. If the medication doesn't flow properly, don't force it. If it's too thick, dilute it with water. If you suspect that tube placement is inhibiting the flow, stop the procedure and reevaluate tube placement.
Watch the patient's reaction throughout the instillation. If he shows any sign of discomfort, stop the procedure immediately.
As the last of the medication flows out of the syringe, start to irrigate the tube by adding 30 to 50 mL of water. Irrigation clears medication from the sides of the tube and from the distal end, reducing the risk of clogging. If administering more than one medication, flush between each medication with 15 to 30 mL of water to maintain patency of the tube.
When the water stops flowing, quickly clamp the tube. Detach the syringe and dispose of it.
Fasten the NG tube to the patient's gown, remove the towel or linen-saver pad, and replace linens as necessary.
No time to lie down
Leave the patient in Fowler's position or have him lie on his right side with the head of the bed partially elevated for at least 30 minutes to 1 hour to facilitate flow and prevent esophageal reflux.
If the patient has a gastrostomy feeding button, you may give a tablet or capsule dissolved in 30 to 50 mL of warm water (15 to 30 mL for children) and administer it if liquid form isn't available. Use the same procedure as for feeding the patient through the button. Draw up the dissolved medication into a syringe and inject it into the feeding tube. Withdraw the medication syringe, flush with 50 mL of warm water, replace the safety plug, and keep the patient at a 30-degree angle for 30 minutes to 1 hour.
The procedure is contraindicated if the tube is obstructed or improperly positioned, if the patient is vomiting around the tube, or if his bowel sounds are absent.
Only warm water should be used as a diluent unless otherwise specified. Cold liquid instilled in the enteral tube can cause abdominal cramping.
Dilute liquid medications that can cause local irritation such as potassium.
Consult with a pharmacist if you are uncertain whether a medication can be crushed or given through an enteral tube.
Only use enough diluent to dissolve the medication to avoid fluid overload.
Not on a full stomach
To prevent instillation of too much fluid (for an adult, more than 400 mL of liquid at one time), don't schedule the drug instillation with the patient's regular tube feeding, if possible. If you must schedule a tube feeding and medication instillation simultaneously, give the medication first. Remember to avoid giving foods that interact adversely with the drug.
If the patient receives continuous tube feedings, stop the feeding and check the quantity of residual stomach contents. If it's more than 50% of the previous hour's intake, withhold the medication and feeding and notify the doctor.
If the NG tube is attached to suction, be sure to turn off the suction for 20 to 30 minutes after administering medication. (See Documenting use of NG tube medications.)
Outline