What is the criteria for selecting a preparation medication to initiate in a patient?

From the Guidelines

The selection of a bowel preparation regimen should be based on the individual's medical history, medications, and prior colonoscopy results, with no single purgative proven superior for ambulatory patients at low risk for inadequate bowel preparation. When determining which prep medication to start a patient on, several factors must be considered, including the patient's medical history, current medications, and the results of any previous colonoscopies 1. The US Multi-Society Task Force on Colorectal Cancer recommends limiting dietary modifications to the day before colonoscopy for ambulatory patients at low risk for inadequate bowel preparation, and suggests using low-residue and low-fiber foods or full liquids for early and midday meals when using a split-dose bowel preparation regimen 1.

Key considerations in choosing a bowel prep regimen include:

• The patient's risk for volume overload or electrolyte disturbances, in which case hyperosmotic regimens should be avoided 1
• The use of a split-dose administration of bowel preparation purgatives, which is recommended for all patients regardless of high-volume or low-volume preparation 1
• The consideration of a same-day regimen as an acceptable alternative to split dosing for individuals undergoing an afternoon colonoscopy, but potentially inferior for morning colonoscopies 1
• The potential adjunctive use of oral simethicone to improve bowel preparation quality 1

It is also important to assess bowel preparation quality after all washing and suctioning have been completed, using reliably understood descriptors to communicate the adequacy of the preparation 1. Ultimately, the goal is to achieve an adequate bowel preparation, defined as a preparation that allows for standard screening or surveillance intervals to be assigned based on the findings of the colonoscopy 1.

From the FDA Drug Label

For the Relief of Symptoms Associated with Diabetic Gastroparesis (Diabetic Gastric Stasis) If only the earliest manifestations of diabetic gastric stasis are present, oral administration of metoclopramide may be initiated. However, if severe symptoms are present, therapy should begin with metoclopramide injection (IM or IV)

The choice of prep medication to start a patient on depends on the severity of symptoms.

• If the patient has mild symptoms, oral administration of metoclopramide may be initiated.
• If the patient has severe symptoms, therapy should begin with metoclopramide injection (IM or IV) 2.

From the Research

Determining Prep Medication for Patients

To determine which prep medication to start a patient on, several factors must be considered, including the patient's medical history, age, and the specific procedure they will be undergoing.

• The choice of bowel preparation depends on various factors, including patient tolerance, medical history, and the type of procedure being performed 3, 4, 5.
• Studies have compared the efficacy and safety of different bowel preparation agents, including polyethylene glycol (PEG), sodium picosulfate/magnesium citrate, and oral sodium phosphate tablets 3, 4, 5.
• The results of these studies suggest that low-volume PEG and sodium picosulfate/magnesium citrate are better tolerated than large-volume PEG, and that sodium picosulfate/magnesium citrate may provide superior mucosal cleansing 3, 4.
• In children, high-volume PEG, low-volume PEG combined with bisacodyl, and sennosides have been compared, with no significant differences found in terms of efficacy and acceptability 6.
• Over-the-counter therapies for chronic constipation, including polyethylene glycol, senna, and psyllium, have also been evaluated, with good evidence supporting the use of polyethylene glycol and senna as first-line laxatives 7.

Factors Influencing Prep Medication Choice

Several factors can influence the choice of prep medication, including:

• Patient age and medical history 5, 6
• Type of procedure being performed 3, 4
• Patient tolerance and acceptability of the preparation agent 3, 4, 5
• Efficacy and safety of the preparation agent 3, 4, 5
• Potential interactions with other medications 7

Considerations for Specific Patient Populations

Certain patient populations may require special consideration when selecting a prep medication, including:

• Physically disabled patients, who may require a smaller volume preparation agent 4
• Children, who may require a different preparation agent or dosage regimen 6
• Patients with certain medical conditions, such as kidney disease or gastrointestinal disorders, who may require a specific preparation agent or monitoring 7