What is lactose intolerance?
Lactose intolerance occurs due to the damage of epithelial cells lining the digestive tract where the enzyme lactase (that digests lactose) is formed, leading to its inadequate production. When the lactase level is low, lactose cannot be digested. This undigested lactose remains in the intestines and creates an osmotic force, moving water into the bowel. This stimulates the peristalsis, leading to rapid intestinal transit, further impairing the absorption. The increased volume of bowel content leads to borborygmi, bloating pain and cramps. Lactose passes into the colon where it is fermented by the colonic bacteria producing a variety of gases, organic acids and other irritating chemicals
Click on the link below to find out: Different types of lactose intolerance & differences between milk allergies and lactose intolerance |
Tests for Lactose Intolerance
A. Hydrogen Breath Test - this tests the amount of hydrogen that is breathed out. When lactose is fermented by bacteria in the bowel, instead of being converted by lactase, more hydrogen is produced.
B. Elimination diet – this involves removing foods that contain lactose to see if the symptoms improve. If the symptoms reappear once the foods are reintroduced, then lactose intolerance is most likely the cause. Before making any major changes to your diet, it’s a good idea to go see your doctor. C. Another cheap and simple ‘test’ is to compare whether the person can tolerate lactose-free milk rather than ordinary milk. Please consult a health care professional for further information. |
Management of Lactose of Intolerance
Most patients with primary lactose intolerance are managed with lactose-restricted diet, use of lactase enzyme substitute, provision of adequate calcium intake and substitution with alternative products. Patient with late-onset lactase deficiency (secondary lactose intolerance) are put on lactose free diet at the time of diagnosis until symptoms subsides. Lactose is then gradually reintroduced into the diet, to determine the quantity tolerated without causing symptoms.
Note: Eliminating milk and other dairy products from your diet can result in inadequate nutrition, unless an appropriate selection of substitute foods is eaten. Dairy is a rich source of calcium, and is the biggest contributor of calcium in the Australian diet. |
Lactose in medications
Lactose is commonly used as an inactive ingredient, primarily as filler in the manufacture of tablets and capsules. There have been some reports describing lactose-intolerant patients experiencing adverse reactions to the lactose content of medications while being on a lactose-restricted diet. In these cases, the majority of these patients were extremely sensitive to lactose-containing products.
It has been reported that the amount of ingested lactose necessary to produce adverse effects varies but in general, it ranges between 12 - 18 grams of lactose (approximately 8 to 12oz of milk). Notably, most oral tablets or capsules contain quantities of lactose that are far less than 12 – 18g, one would not expect such small quantities to result in GIT symptoms. However, there are cases in the past that have reported suggesting certain individual may react to very small quantities of lactose. In another study, researchers concluded drugs containing as small of amount as 400mg of lactose did not cause severe gastrointestinal symptoms compared to placebo.
However, patients who are ingesting multiple lactose-containing medications may experience symptoms of lactose intolerance due to the cumulative lactose intake from these medications plus other dietary intake.
Symptoms can be decreased to some degree with supplemental lactase enzymes (Ex. Lacteeze) and resolved when the patients discontinued the medication. If symptoms persist despite the use of lactase supplements, patients may need to seek an alternative formulation of the same drug or an alternative drug that dose not contain lactose.
It has been reported that the amount of ingested lactose necessary to produce adverse effects varies but in general, it ranges between 12 - 18 grams of lactose (approximately 8 to 12oz of milk). Notably, most oral tablets or capsules contain quantities of lactose that are far less than 12 – 18g, one would not expect such small quantities to result in GIT symptoms. However, there are cases in the past that have reported suggesting certain individual may react to very small quantities of lactose. In another study, researchers concluded drugs containing as small of amount as 400mg of lactose did not cause severe gastrointestinal symptoms compared to placebo.
However, patients who are ingesting multiple lactose-containing medications may experience symptoms of lactose intolerance due to the cumulative lactose intake from these medications plus other dietary intake.
Symptoms can be decreased to some degree with supplemental lactase enzymes (Ex. Lacteeze) and resolved when the patients discontinued the medication. If symptoms persist despite the use of lactase supplements, patients may need to seek an alternative formulation of the same drug or an alternative drug that dose not contain lactose.
List of medications that are lactose-free
The amounts of excipients in medications are not readily accessible by health professionals. They may also be unaware that lactose-free alternatives are available. It’s reported that most individuals can tolerate up to 11.8 g of lactose per day (250 mL of milk).
However, researchers feel that the amount of lactose present in drug formulation is enough to contribute towards symptoms of a sensitive patient. For example, there are reports of symptoms after ingesting 200mg of lactose. Thus, alternatives formulation should be considered to take into account patient adherence and compliance. Click on the link below to find out which medications contains lactose Medications that contains lactose |
Lactose intolerance and Irritable Bowel Syndrome (IBS)
Currently, secondary lactose intolerance in patients with established GI diseases are non-conclusive. IBS for example is highly prevalent in the western world (25%) and usually are presented with at least one of the following symptoms: abdominal pain, bloating, constipation and/or diarrhoea. IBS symptoms are often indistinguishable from those of lactose intolerance. However, it should be noted that lactose intolerance does not lead to the development of IBS. Thus, lactose intolerance should be excluded before the diagnosis of IBS is made in a patient.
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References
a) http://lactose.com.au/intolerance
b) Eadala P, Waud JP, Matthews sb, Green JT, Campbell AK. Quantifying the hidden lactose in drugs used for the treatment of gastrointestinal conditions. Aliment Pharmacol Ther 2009, 29(6), 677-687.
c) Zarbock SD, Magnuson B, Hoskins L, Record KE, Smith KM. Lactose: The hidden culprit in medication intolerance. Orthopedics 2007, 30(8):615-618.
d) Halbrich M, Ben-Shoshan M, Rex Gregory. Friend or Foe? Figuring out the difference between FPIES, IgE-medicated allergy and food intolerance. BMJ Case Rep 2014.
e) Montalto M, Gallo A, Santoro L, D’Onofrio F, Curigliano V, Covino M, Cammarota G, Grieco A, Gasbarrini A, Gasbarrini G. Low-dose lactose in drugs neither increases breath hydrogen excretion nor causes gastrointestinal symptoms. Alimentary Pharmacology & Therapeutics 2008, 28: 1003-1012.
f) Tomar BS. Lactose intolerance and other disaccharidase deficiency. Indian J Pediatr 2014.
a) http://lactose.com.au/intolerance
b) Eadala P, Waud JP, Matthews sb, Green JT, Campbell AK. Quantifying the hidden lactose in drugs used for the treatment of gastrointestinal conditions. Aliment Pharmacol Ther 2009, 29(6), 677-687.
c) Zarbock SD, Magnuson B, Hoskins L, Record KE, Smith KM. Lactose: The hidden culprit in medication intolerance. Orthopedics 2007, 30(8):615-618.
d) Halbrich M, Ben-Shoshan M, Rex Gregory. Friend or Foe? Figuring out the difference between FPIES, IgE-medicated allergy and food intolerance. BMJ Case Rep 2014.
e) Montalto M, Gallo A, Santoro L, D’Onofrio F, Curigliano V, Covino M, Cammarota G, Grieco A, Gasbarrini A, Gasbarrini G. Low-dose lactose in drugs neither increases breath hydrogen excretion nor causes gastrointestinal symptoms. Alimentary Pharmacology & Therapeutics 2008, 28: 1003-1012.
f) Tomar BS. Lactose intolerance and other disaccharidase deficiency. Indian J Pediatr 2014.