Triamteres

Definition

Triamterene is an organic-chemical substance and is used in medicine to eliminate excess fluid from the body, for example in the case of edema. This is done through increased urination. Triamterene acts here at the end of the urinary system (distal tubule and collection tube) and is therefore potassium-saving.

Chemical name

2,4,7-Triamino-6-phenyl-pyrazino[2,3-d]pyrimidine

Fields of application

The main application for triamterene is in high blood pressure (hypertension) and water retention in the legs (leg edema)

Effect

Triamterene blocks the aldosterone-dependent (mineral corticoid from the adrenal cortex) sodium channel at the end of the urine-forming system (distal tubule and collection tube). Here, sodium (Na+) is normally reabsorbed into the cells under the action of the mineral corticoid aldosterone. Since Na+ is positively charged, a positively charged particle must be expelled from the cell in return.

In this case it is potassium (K+). Sodium draws the water behind it into the cells and then into the bloodstream. If this sodium channel is blocked by triamterene, less Na+ is absorbed into the cells, thus less water is transported back into the bloodstream and less potassium is released into the urine.

Triamterene is therefore a potassium-saving diuretic. Triamterene can therefore work all the better the more Na+ reaches the end of the urinary system. Triamterene is therefore often used in combination with other substance classes which intervene further upstream in the urinary system and increase the Na+ concentration in the urine (e.g. hydrochlorothiazide, Bemetizid, Propranolol-HCl).

Contraindications

Purely for triamterene there are some contraindications for which the use of triamterene should be avoided. If the blood level of potassium is too high (hyperkalemia) or the blood level of sodium is too low (hyponatremia), Triamterene should not be used. Furthermore, the use of triamterene is not allowed if the function of the kidney is severely restricted.

This is the case when the kidneys produce less than 30 ml/min of urine and/or blood creatinine levels are higher than 1.8mg/100ml. In this case Triamterene is ineffective. Further contraindications result from the combination with other active ingredients.

If the following factors are present, the indication for the use of Triamterene should be very strict. If the kidney only produces 30-60ml/min urine or the creatinine level in the blood is between 1.8-1.5ml/100ml, then the potassium concentration in the blood should be monitored, as increased potassium levels can occur more easily in this case. The intervals between doses of the drug should also be monitored as the half-life (the time until half of the drug has been broken down in the blood) of the drug in the blood can be prolonged.

Increased caution is also advised in case of kidney stones. There is also an increased need for control in diabetes mellitus (diabetes) and when folic acid deficiency is suspected, for example in liver damage, alcohol abuse and pregnancy with malnutrition. Strict indication is also required in pregnancy and lactation.

There is not enough experience to know whether the drug and in what way it can possibly harm the unborn child. No damage to the unborn child could be detected in animal experiments. However, an effect on growth could be observed. Triamterene passes into breast milk. Further application restrictions result from the combination with other active ingredients.