Microsoft word - creontalk

Integrating the patient experience into clinical practice
Mark Buckley-Sharp MBBS DipBiochem FRCPath
What is Creon?

Extract of digestive enzymes from pig pancreas; pelleted, and with each pellet having a soluble (acid-resistant) coating; packaged in gelatine capsules. Three available ‘strengths’ contain Lipase - 10KU, 25KU, and 40KU Other main enzymes are Amylase and Protease, at relative unit strengths of 64% and 4% of Lipase respectively. Other pancreatic enzymes are present, but are not standardised. Shelf-life is three years from manufacture. Enzymes degrade during storage, therefore KU activity of capsules reduces.
Indications for Creon

Pancreatic insufficiency requiring digestive enzyme replacement Cystic fibrosis (majority users of Creon) Chronic pancreatitis Surgical pancreatectomy NOTE: These indications are for mal-digestion. While mal-digestion prevents proper absorption by the gut, the primary disorder is not a mal-absorption.
Symptoms of Mal-Digestion

The production of copious and foul-smelling stools, which are hard to flush away. The latter being caused by dietary fat remaining in the stools. Upper-gut bacterial overgrowth, leading to fermentation of poorly digested food, and excessive wind. Feeling of fullness, and cramping pains due to excessive volume in the small bowel. Extreme lethargy (24h). ? Due to fluid shifts. Osmotic purge due to large amounts of undigested food in the large bowel. Excessive flatus due to large bowel bacteria being ‘overfed’. Deteriorating nutritional status due to lack of available digested food. Macronutrients: Energy, Protein Micronutrients: Vitamins, Minerals
Effects of Creon

Creon restores (reasonably) adequate digestion, thus also removing the effects of Prescribing & Dispensing Creon (Primary Care and TTAs)

Always prescribe two strengths of Creon so that the patient can make
up any required dose.
The two strengths should normally be 10KU and 25KU. The 40KU strength should not be used unless it is already known that the patient definitely requires this strength. (Manufacturer’s recommendation.) Always prescribe in whole numbers of the pack size.
The pharmacist should never be required (and should query any request) to open a pack to dispense it in part. Once opened, the material will deteriorate more quickly, and the use-by date on the pack is invalidated. The standard pack sizes are shown in the prescribing modules of GP computer systems. 10KU: 100 capsules. A pack size of 50 may be dispensed, depending on source (EU wide) but this size should not be prescribed. Always overprescribe packs. Do not attempt to calculate an exact number for the standard 28 day prescribing period. The patient will maintain an adequate forward stock to protect against The patient will arrange with the community pharmacist to under- dispense against the prescription as required to manage the personal stock. Dosage must always be ‘As Directed’
The prescription must not state an actual dose of capsules, or timing.
Prescribing & Dispensing Creon (Inpatients)

Creon must not appear in the one-time section of the drug chart. Creon must not appear in the main timed section of the drug chart. Creon prescriptions must be made in the prn section of the drug chart.
Creon must be dispensed so that it is available to be taken exactly with all
food. It cannot wait for routine drug rounds.
Creon is not a controlled drug and does not need to be kept locked away. Always prescribe their current strengths of capsules on the chart. Ideally, have the patient use their personal stock and let them keep it for immediate access. Dispense whole packs to top up as required. Always prescribe both 10KU and 25KU capsules on the chart. Patients will need advice and assistance with dose calculation from a dietician or other adequately informed clinician. Use discretion, and agree with ward pharmacist, whether to dispense whole packs to the patient, or whether to dispense individual capsules prn from ward stock. The information in this hand-out is a professional opinion. Implementation in detail is a matter for clinical decision. Effect of Anatomy on Digestion

In the normal state, the stomach holds food for acid maceration; for the start of protein digestion; and for a degree of sterilization. Where the pylorus is excised (gastro-jejunostomy; traditional Whipple’s), food will pass to the jejunum before complete maceration. This will: Where the pancreas is connected to the stomach (Whipple’s variant), the patient will be on acid suppression with Omeprazole. This will: Make upper gut colonisation more likely. Increase the risk of bacterial gastroenteritis and/or cholangitis.
Assessing the Need to Start Creon
(Omitting congenital cystic fibrosis and gradual deterioration in chronic pancreatitis.)
Creon can be assumed to be required after total pancreatectomy. All patients should be formally assessed on starting food after partial
pancreatectomy. Document clinical history about:
Short transit time of unchanged or poorly digested food. NOTE: Opioid pain relief may inhibit gut motility. High calorie supplements, such as Ensure, should not be offered unless pancreatic defect has been ruled out, or Creon support has been started. Ensure, etc., can have a dramatic and unpleasant effect with pancreatic insufficiency.
Starting a Patient on Creon

Provide a copy of the local patient handbook. A dietician, a clinical nurse specialist, another informed clinician, or some
combination of these, must provide direct and effective patient education.
NOTE: Other sections of this paper have more detail about the following summary topics. The educating clinician(s) should explain about: Compositions of foods and how these affect Creon dose calculations. A starting level of dosage, and how this is calculated. The educating clinician(s) should also explain to the patient that: Finding a workable pattern of foods and Creon doses takes experience. There will be mistakes and problems from which to learn. The patient will eventually know more about their own Creon usage than any clinician. The patient will meet many clinicians who know nothing useful about
Creon. It will then be the patient’s turn to educate.
The information in this hand-out is a professional opinion. Implementation in detail is a matter for clinical decision. Cultural Issues with Creon

The materials present in Creon may cause difficulty with certain cultural groups: Vegans may object to the animal sources of the materials. Hindu patients may object to the bovine source of the capsules. Jewish and Muslim patients may object to the porcine source of enzymes. Contradictory opinions (fatwas) are published by Muslim sources, ranging from prohibition to acceptability on grounds of necessity.
How to Take Creon

Creon capsules should be swallowed whole, and taken at the same time as food. An alternative is to open the capsule(s) and sprinkle on food. This must only be done with food which will not be chewed, such as soup or puree. Where the food amount requires multiple capsules, then the dose should be divided during the whole meal. Food and Creon should be taken with a good quantity of fluid. Do not underestimate the quantity of fluid provided by the stomach, bile and pancreatic juice in the normal person, where these quantities may not be secreted in an affected patient.
Very Important for Everyone

Always carry Creon with you. Stock up with a whole day’s requirements each
morning, of whatever mix of capsules you typically need plus spares.

Adverse Effects of Creon

Adverse effects are listed in the manufacturer’s advice leaflet. Some of these are realistic, but some are unrealistic and appear to be just for safety cover. Rare but always possible with any medicine on first exposure. Allergy may be to the pig pancreatic extract, or the beef gelatine capsule, or to other components. Allergy may show as a skin eruption. However, as none of the medicine is absorbed, it may only show as gut cramps (an ‘invisible’ eruption?) Large bowel strictures are reported as a late reaction to the excipients. Reported adverse effects which are improbably related to Creon: Creon contains no more than a trivial amount of protein: less than a small spoonful of boiled egg. Like normal pancreatic enzymes, it is itself digested on passage through the gut. Taking too little Creon is a more likely cause of diarrhoea. Taking more Creon, and moving from a state of purge to normality, might be wrongly interpreted as constipation. Adverse effects not mentioned, but which should be considered: If Creon capsules are opened and chewed with food, then Creon pellets may get lodged between the teeth. The pellet is then likely to activate and digest the gums. The information in this hand-out is a professional opinion. Implementation in detail is a matter for clinical decision. Calculating Creon Dosage - Introduction
Overall, there are some very dubious recommendations available on the internet.

A) Stupid suggestions from various sources:
“500-2500U per kg body weight per meal.” This is widely quoted, including by US-FDA, but is a bizarre suggestion. Creon is not absorbed. Body weight cannot be related to any volume of distribution. The range is too vague to be helpful. “The patient should only change the dose on medical recommendation.” On the contrary, the patient must be in charge of calculating the dose, depending on the food eaten. The patient does need education about the method of calculation. “Dose adjustments should be made over several days.” No. Unless this refers to changing the method of calculation to find a better optimum dosing schedule. Even then there is no need to delay a change. B) Rather more sensible suggestions, including from Pancreatic Cancer UK: “10KU per snack (if containing fat)” C) Other available suggestions worth considering: “A patient taking more than 10KU per kg body weight per day should be carefully reviewed:” This level (say >500KU/day) has the potential for long-term toxicity. The patient may be taking far too much more than actually required. For some reason the medication may be ineffective.
Calculating Creon Dosage Properly
These suggestions are based on personal experience with some extrapolation.

Food and eating patterns:
Try to settle into a predictable pattern of eating, not necessarily by time but by types and amounts of food. A predictable pattern of foods should give a predictable pattern of doses. Take Creon at the start of any meal. If multiple capsules are used, space them out during the meal. At a restaurant, where courses may be spaced out, treat each course as a separate meal with its own dose plan. Learn about the labelling of foods in supermarkets, especially fat content. From that, learn to estimate the content of fresh foods, unlabelled foods, or anything you may be offered to eat. Oils and fats used in cooking fresh vegetables must be included in your calculations, as must the basic energy staples of potatoes, rice, maize, and cereals. But, sugary confections and drinks, fruit, and other vegetables can be ignored. If you believe you have at least some pancreatic function, then: Try taking no Creon with small snacks like one biscuit or the milk in tea/coffee. There is something uniquely satisfying about eating an ice-cream knowing that, unlike your partner eating the same, you may not be absorbing the calories. The information in this hand-out is a professional opinion. Implementation in detail is a matter for clinical decision. Learn to recognise foods which are highly imbalanced. Manage their use since they can put you over your estimated normal range(s) of content. Indian cuisine has much more fat than Chinese cuisine. Beware macaroni cheese! Run away from a fondue! (Anyway, a fondue is old-fashioned!) Don’t overeat just because you are enjoying yourself. When beginning to use Creon, try a starting dose of 1KU per 1g fat.
A reasonable daily diet includes at least 70g fat. There is no need to be exact. Round doses up to the next capsule amount (10 or 25KU). Since the medicine is reducing in strength on storage, slightly overestimate the dose numerically. In summary, aim to start at about 100KU per day, divided between meals roughly in proportion to size. Then, experiment until you can settle into a simple plan which is easy to remember. My Example (Do not assume this works for anyone else): Fresh fruit; small cereal with milk; one toast with butter & marmalade; water. One round sandwich; 25g cheese; tomato; fruit; water/squash. Variable but not too large or unbalanced; water/squash. 5 x 25KU; approximately 150/month (prescribed 180). 1-2 x 10KU; approximately 40/month (prescribed 100). When eating out, I have to look at a plate of food; make an estimate of its content; and adjust Creon dose accordingly. Or, I order according to the dose I want to take. I have followed these policies with relatively few problematic incidents for over 5 years. However, it took over 6 months to find this working pattern. If the dose schedule works, then you are taking either enough, or possibly more than necessary. It takes some planning and courage to break a pattern that works. Recently, I have experimented with cutting all doses (as shown above) by about one-third. So far it is working, but it is playing havoc with my stock control. The information in this hand-out is a professional opinion. Implementation in detail is a matter for clinical decision. LONG TERM MANAGEMENT OF MICRONUTRIENTS
AFTER WHIPPLE’S PROCEDURE

Macronutrients (Fat, Protein, Carbohydrate and Total Energy) are adequately managed after
Whipple’s procedure if the patient can maintain a stable body weight. This note concerns the
long term management of micronutrients where deficiencies may be occult and insidious in
onset.
There should be planned surveillance for micronutrient deficiencies by agreement
either by surgeons during follow-up, or by the primary care physician.

Fat Soluble Vitamins
Relevant vitamins include A, D, E, and K. Of these, vitamin D may be the easiest to use as a proxy marker. Measure Serum Vitamin D. The risk of vitamin D deficiency arises from possible malabsorption of the vitamin, consequent on maldigestion of fat. Maldigestion of fat should be treated with Creon replacement, but checks should still be made for vitamin D deficiency. It may be desirable for the patient anyway to take a continuous OTC multivitamin supplement, which provides 100% of recommended daily amount (RDA) on top of the normal diet. Any vitamin D deficiency detected while on OTC supplementation may require review of other fat soluble vitamins and prescription of pharmacological doses. Relevant vitamins include B-series, Folate, and C. Of these Vitamin B12 is the only likely problem, where the risk arises if partial gastrectomy has diminished intrinsic factor. Measure Serum Vitamin B12+Folate, and review against any FBC results (? macrocytosis). As with fat soluble vitamins, use of a continuous OTC multivitamin supplement may be helpful. However, this will not contain intrinsic factor. The normal liver store of vitamin B12 is up to 2 years. A deficiency is unlikely to be detected sooner than this after Whipple’s procedure. Any vitamin B12 deficiency detected while on OTC supplementation may require replacement by injection. It is not widely realised that the only site of active iron absorption is in the
duodenum. This is removed by Whipple’s procedure leaving only a highly inefficient
passive absorption process in the small gut.
While gross iron deficiency leads to measurable anaemia, slow onset iron deficiency leads first to low ferritin without obvious anaemia. Measure Serum Ferritin with all follow-up FBC tests. It may be desirable for the patient anyway to take a continuous OTC multivitamin supplement also containing 100% RDA of minerals including iron. Any low ferritin detected may require review of other minerals and prescription of pharmacological doses of iron. As the patient will be unable to absorb iron quickly, what is required is a tolerable dose of iron which can be taken long term. Consider Ferrous Sulphate, 1 daily, and continue to review Serum Ferritin. Other minerals of interest may include copper, zinc and selenium. Serum levels of these can be tested if required. The information in this hand-out is a professional opinion. Implementation in detail is a matter for clinical decision. PERI-OPERATIVE FLUIDS
The “British Consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients” were last updated in 2011 by a group of six professional bodies including those for Surgery, Intensive Care, Nutrition and Clinical Biochemistry. The principal concern is that intravenous fluids are given without adequate policies or planning, leading frequently to overuse. Of necessity, the following are highly abbreviated and the full guidelines should be studied in order to review current practice and identify improvements. The only routine crystalloid solution used should be Hartmans (or Ringer). All patients require adequate amounts of free water per day. Any patient who develops interstitial oedema has been overdosed on electrolyte. or water, or both. Oedema compromises tissue viability. While some oedema at the operative site is inevitable, peripheral oedema is due to mismanagement of fluids. There are only three purposes for intravenous fluids. All prescriptions of fluids should be capable of explicit justification against each of these separately: Replacement of normal baseline requirements. Normal Daily (24h) Baseline Requirements: For respiration, sweating, and a realistic urine output. The guidelines show a range, but 70 is easy to remember as 0.5 L of isotonic crystalloid solution. Be aware that many drugs eg, antibiotics contain significant amounts of sodium, and this should be considered in any calculations. The guidelines show a range, but 70 is easy to remember, being the same as sodium. The simplest baseline replacement is 1.5-2.0 L 5% dextrose and 0.5 L Hartmans per day, with potassium added during the regime. Urine is covered by the baseline requirements and is not a loss to be replaced. All drains should be replaced mL for mL with crystalloid added to the baseline. Invisible internal losses into the gut may have to be estimated but are temporary. Large volumes of gastric drainage may require some substitution of Hartmans by Saline (extra chloride). Smaller volumes will be within calculation tolerances. Serum U&E are traditional, but are uninformative unless severely disordered. Consider Urine U&E as a far better indication of imbalances. Routine use of 3 L IV of saline per day is never an acceptable treatment.
The information in this hand-out is a professional opinion. Implementation in detail is a matter for clinical decision.

Source: http://users.tinyworld.co.uk/mark.buckley-sharp/research/creontalk.pdf