Side effect
With increasing age and increasing dose, the frequency of side effects increases significantly. Constipation is particularly frequent, but is easily treatable in most patients and only a few of them stop treatment. In the gastrointestinal tract, diarrhoea, fatty stools, vomiting, bleeding, swallowing difficulties and intestinal obstruction can also occur.
For most of the side effects no frequencies can be named. One observed side effect is hemorrhagic diathesis. This is a coagulation disorder with an increased risk of bleeding.
By influencing the absorption of bile acid, a deficiency of the fat-soluble vitamins A, D, E and K can occur. The vitamin A deficiency can lead to night blindness. A loss of appetite is also possible.
Dizziness, headaches, tiredness and sensations of discomfort can also be the result of taking colestyramine. The skin may react with redness and allergic reactions. Osteoporosis and muscle pain as well as joint pain are possible side effects. All reported side effects may occur, but are to a large extent rare events. With possible side effects those affected should always talk to their treating physician.
Interaction
Colestyramine reduces the absorption of many substances in the gastrointestinal tract, which can lead to the fact that other orally taken drugs are less easily absorbed. Drugs that are subject to the liver circulation can also be altered in their effect. Digitoxin in particular is one of these.
When discontinuing colestyramine, toxic doses may occur. Anticoagulant therapies, for example with Marcumar, must be closely monitored, as they depend on the vitamin K level and vitamin K is less easily absorbed. A reduced effect of the pill cannot be ruled out with certainty either.
Although colestyramine is not absorbed directly into the body, a reduced effect of the pill cannot be ruled out. Colestyramine influences the formation of cholesterol and can therefore also lead to hormonal fluctuations in the sex hormones. In addition, the oral intake of medicines, such as the Pill, can be impaired.
Those affected should therefore use other forms of contraception. A direct interaction of alcohol and colestyramine has not been reported. However, possible side effects in the gastrointestinal tract, such as diarrhoea, may be more severe if alcohol is taken at the same time. If there is an increase in symptoms under alcohol, colestyramine should only be used with a time lag from alcohol consumption. If alcohol is abused, liver damage and damage to the bile ducts can lead to further side effects.
Dosage
For colestyramine sachets used to prepare a suspension, one to four sachets a day are recommended for adults. This can be increased to up to six sachets, i.e. 24g of colestyramine. Higher dosages have an influence on the normal fat absorption in the intestine.
In children, the dosage is adjusted to body weight and usually started with one dose. The dosage is then increased at regular intervals until the treatment is successful. In case of interactions, a time interval between taking colestyramine and other medications should be observed.
