General guidelines for administration of medications through enteral feeding tubes

Standard tablets
Crushing should be avoided. If crushing is the only option then the tablets should be crushed well enough to prevent clogging of the tube. Care should be taken when crushing drugs which have a high incidence of allergic reactions e.g. antibiotics, chlorpromazine. It is important to ensure that the whole dose is administered.

If tablets need to be halved in order to obtain the prescribed dose, it is best to cut them using a tablet splitting device. Such devices split tablets more accurately than splitting scored tablets by hand, or cutting tablets with a knife.⁵⁵⁸

Sugar-coated (s/c) and film-coated (f/c) tablets
These tablets are usually coated to improve appearance or to mask unpleasant taste, and they are usually suitable for crushing.²²⁵ However the presence of a coating may make crushing difficult and increase the probability of the drug blocking the enteral feeding tube. If these tablets are crushed it is particularly important to ensure that the coating is well broken up, and that the feeding tube is flushed well after the dose.

Dispersible and effervescent formulations
These have a low osmolality and will not cause diarrhoea. Most dispersible and effervescent formulations contain sodium, which may be a problem in sodium restricted patients.

Enteric-coated (e/c) tablets - do not crush
The enteric coating is designed to prevent drug dissolution in the stomach and to promote absorption in the small intestine. If the tablet is crushed and passed down the enteral feeding tube, undesirable side effects may occur. These could include stomach irritation and a decrease in drug effectiveness. When crushed, the tablet will break into small chunks that bind together when moistened and subsequently clog the feeding tube.^{4,212,214,593}

Buccal and sublingual tablets - do not crush
Drugs formulated in these dosage forms such as prochlorperazine (Buccastem^®) or glyceryl trinitrate are designed not to pass through the stomach in order to avoid the first pass metabolism effects in the liver. If these tablets are passed down the enteral feeding tube, drug effect will be decreased. Buccal and sublingual tablets are suitable to be used as normal in most cases even if a patient becomes nil by mouth, provided that the patient is safe to have tablets held in their mouth, and is still producing normal quantities of saliva.^225,249

Modified-release (MR) and controlled-release (CR) preparations (also ER, SR, LA, XL, XR, Retard, Once Weekly) - do not crush
These drugs are intended to be released gradually over time, and often have a special coating to enable this. If the tablet is crushed and passed down the enteral feeding tube, an increase in the expected peak plasma level may occur ("dose-dumping").²²⁵ The patient will be initially exposed to significantly higher-than-normal levels which will increase the chance of side effects. Later, the drug will not last the full dosage interval, resulting in a period with little or no drug present, possibly resulting in loss of control of the patient's condition. Modified-release preparations are also unlikely to disperse completely when crushed, leading to an increased risk of tube occlusion.²¹⁴

Cytotoxic tablets - do not crush
All staff should avoid contact with cytotoxic drugs. There is a risk of cytotoxic powder being aerosolized if cytotoxic tablets are crushed, exposing staff to hazardous materials.²²⁵ Cytotoxics should be handled in accordance with local procedures. Contact Pharmacy for advice.