Pharmacological Aspects

of IF – Key Tips Gavin Leahy

Senior Pharmacist

Salford Royal NHS Foundation Trust

Overview

General considerations

MDT approach

Medicines Optimisation

Drug treatment of high output stomas

Drug absorption issues

Specific medication

Drug Treatment of High Output Stomas

Maximise gastrointestinal function

Use a combination of drugs

Antimotility drugs

Antisecretory drugs

Glucose/Saline solution

Response affected by whether patient is a “secretor” or “absorber”

Antimotility Drugs

Act on local opiate receptors in gut wall

Reduce intestinal motility so increase GI transit time

Benefit seen in secretors but particularly effective in absorbers

Take 30-60min before meals

Loperamide used as first line

Codeine can be added

Evidence to suggest beneficial to use in combination

Antimotility Drugs - Considerations

High dose Loperamide

64mg daily

Concordance

High tablet burden

Care with hypertonic syrups

Crush tablets/open capsules

Self administration?

Antisecretory Drugs

Proton Pump Inhibitors

Reduce gastric acid secretion to reduce sodium and water excretion

Greatest benefit seen in net secretors

Omeprazole

Good dose/ response curve

Well absorbed in the duodenum and upper small bowel

Dose/route titrated according to stoma pH (homecare considerations)

Use of MUPS formulation?

Antisecretory Drugs

H2 Antagonists

2nd line agent to proton pump inhibitors

Greatest benefit seen in net secretors

Ranitidine

Evidence based dose of 300mg bd

Useful in patients who can’t tolerate PPIs (allergy, hypomagnesaemia, altered

LFTs)

Antisecretory Drugs

Octreotide

Reduces salivary, gastric, pancreatico-biliary secretions

Increase bowel transit time

Greatest reduction in output seen in secretors

2nd line agent

Equivalent effect to proton pump inhibitors

Unlicensed indication – cost/administration implications

Glucose/Saline Solutions

Avoid drinking hypotonic fluids

Glucose/Saline solutions reduce sodium and fluid loss

Concentration of sodium at least 90mmol/L

Various solutions available

Double Strength Dioralyte(120mmol Na/L) - 10sachets in 1L

Considerations

Adherence

Education of HCPs

Palatability of Glucose/Saline Solutions

Switch to Dioralyte Relief?

Importance of Citrate

Add flavouring and keep chilled

to improve palatability

Drug Absorption

Very difficult to predict – significant interpatient variability

BPNG Handbook of drug administration

Drug companies have very little data on file

“well absorbed throughout GI tract”

Look at time to peak concentration

Reduce the output as much as possible to improve absorption

Drug Absorption

How much and what type of

bowel remaining

Use other routes if possible:

transdermal, parenteral, rectal

Give more often or increase dose

Can you measure drug levels?

Use of liquids, syrups?

Crush tablets, open capsules

Avoid use of M/R preparations

Consider the distal route if

available

Distal Route of Drug Administration

Need at least 75-100cm

Caution with choice of drugs

Loperamide to aid distal feeding

Look at time to peak - want 3-4 hours

Success Stories-

Pt needed 450microgram orally of levothyroxine

Swapped to distal route - now on 125microgram via distal feeding tube

Specific Medication Issues

Magnesium Supplementation

Magnesium deficiency is common

Various preparations available

Magnesium Aspartate (10mmol/sachet)

Magnesium Glycerophosphate (4mmol/tablet)

Magnesium Oxide (4mmol/capsule)

Side effects/fluid considerations

S/C infusions?

Check Vitamin D levels

Cost implications?

Vitamin D supplementation

Commonly deficient in short bowel/PN patients

In PN bags only 200 units/day

Recent studies show oral preferable to IM injections

Colecalciferol capsules 20,000 units

Dose - 40,000 units od for 10 days then 20,000 units once a week

Ergocalciferol injection 300,000 units every 3-6 months IM

Recheck levels after 8 weeks

Questions?