Slides in this set
Cholera is not the only diarrhoeal
disease that infect the intestines.
Treatments for these disease take a
number of forms, of which oral
rehydration therapy is one of the
most important.…read more
WHAT CAUSES DIARRHOEA?
Diarrhoea is an intestinal disorder in which watery
faeces produces frequently. The causes include:
Damage to the epithelial cells lining the intestine
Loss of microvilli due to toxins
Excessive secretion of water due to toxins e.g. cholera toxins
Excessive fluid is lost from the body and insufficient fluid is
taken in to make up for the loss. Either way dehydration is a
result this can be fatal.…read more
WHAT IS ORAL REHYDRATION
To treat diarrhoeal disease it's important to rehydrate the patient. Just water is
Water isn't absorbed from the intestines, water is actually being lost
It doesn't replace the electrolytes (ions) that are being lost from the epithelial
You can replace it by using a drip but this requires trained personnel. There needs
to be a suitable mixture of substances that can be taken through the mouth and
be absorbed by the intestines. The trick is to develop a rehydration solution that
uses alternative pathways. Sodium ions are absorbed so that the water potential is
decreased and water enters cells by osmosis.
The rehydration solution contains:
Water: To rehydrate the tissues
Sodium: Replace the sodium ions
Glucose: To stimulate the uptake of the sodium, they provide energy
Potassium: Replace lost potassium and stimulates appetite
Other Electrolytes: Like chloride and citrate ions, to prevent electrolyte imbalance…read more
HOME MADE ORAL REHYDRATION
The most effective, least expensive way to manage diarrhoeal dehydration:
A drink made with:
6 level teaspoons of sugar
1/2 level teaspoon of salt
dissolved in 1 litre of clean water.
You should receive oral rehydration salts (ORS) solution and a daily zinc supplement for 1014
days. Diarrhoea medicines are generally ineffective and can be harmful.
Warning: Be very careful to mix the correct amounts. Too much sugar can make the diarrhoea
worse. Too much salt can be extremely harmful to the child. Making the mixture a little too
diluted (with more than 1 litre of clean water) is not harmful.
Diarrhoea usually cures itself in three to four days with rehydration (drinking a lot of
liquids). The real danger is the loss of liquid and nutrients from the child's body,
which can cause dehydration and malnutrition.
If you have diarrhoea should never be given any tablets, antibiotics or other
medicines unless prescribed by a trained health worker.
The best treatment for diarrhoea is to (1) drink lots of liquids and oral rehydration
salts (ORS), properly mixed with clean water from a safe source, and (2) take zinc
tablets or syrup for 1014 days…read more
DEVELOPING AND TESTING IMPROVED
ORAL REHYDRATION SOLUTIONS
Early rehydration solutions led to side effects especially in children this was
because of the excess sodium
Mixtures with a lower sodium solution but more glucose were tested. However the
additional glucose lowered the water potential in the lumen of the small intestine so
it drew more water from the epithelial cells, making the dehydration worst.
Lowering the glucose reduced the effect but the glucose acted as a respiratory
substrate, so it reduced the amount of energy, Now the problem was how to supply
glucose without having an osmotic effect.
One of the answers was to use starch instead. Starch is large and insoluble so has
no osmotic effect. By experimenting with different concentration of starch, a
rehydration solution was created that released glucose at the optimum rate so it
was taken up as it produced so the water potential was not effected
Rice starch is a popular choice because:
Available in many parts of the world especially where diarrhoeal disease is
Provides other nutrients like amino acids which also helps the uptake of sodium
ions from the small intestines…read more
TESTING NEW DRUGS, INCLUDING
ORAL REHYDRATION SOLUTIONS
Each stage has to be tested for safety, initial testing can be done on tissues
and animals it must be eventually done on humans
1. A small number of humans (20-80), they are usually healthy, they are
given a small amount of the drug to test for side effects. The dose may
increase gradually this stage usually takes around six months
2. A larger sample of humans is taken(100-300) this people have the
condition that is being tested for. This stage checks if the drug actually
works and if there are any safety issues it can take up to 2 years
3. A large scale of people is now taken there are thousands of patient and
some are given a placebo. No one will know who has the real drug until
the trial this is known a double blind trial it can take many years
4. If the drug passes all the stages it may be given a licence but it's still
monitored to check for long term effects.…read more