Side effects
Various side effects can occur during treatment with triamterene. A rash may form on the skin, as in a hypersensitivity reaction and may lead to fever. Muscle tension, headaches, nervousness, dizziness and tiredness may occur.
It can cause palpitations in the heart and affect the regulation of blood pressure to such an extent that one becomes dizzy when getting up from a sitting or lying position (orthostatic regulation disorders). Dry mouth, nausea and vomiting and diarrhoea can also occur. In the blood it can lead to increased levels of potassium (hyperkalemia) and a shift of the blood pH value into the acidic range.
Occasionally, blood count changes may also occur. Decrease in white blood cells (leukopenia) and platelets (thrombopenia). Additional folic acid deficiency leads to anemia with excessive red blood cells (megaloblastic anemia).At the kidney itself, triamterene can lead to increased formation of urinary stones and, especially at the beginning of treatment, to an increase in urea and creatinine in the blood. Depending on the combination with additional active ingredients, it can lead to further side effects.
Interactions
Combinations of triamterene and certain classes of other drugs can either attenuate or increase the effect or increase the side effects. If Triamterene is given together with other antihypertensive drugs or alcohol, the antihypertensive effect is increased. Special caution should be taken with the group of drugs called ACE inhibitors.
With these, in addition to the increased blood pressure reduction, there is also an increased potassium level in the blood, since both drugs, i.e. triamterene and ACE inhibitors, are potassium-saving. The potassium level can also rise if you take additional potassium or use other drugs that also save potassium. The administration of indomethacin (a drug used to treat rheumatic pain) reduces the kidney‘s ability to excrete.
In combination with triamterene, this also leads to an increased potassium level in the blood. In diabetics, the effect of the medication for diabetes (antidiabetics), which can be taken in tablet form, may be reduced. Special caution should be exercised when taking triamterene and lithium at the same time, as this can lead to increased damage to the heart and nerves (cardio- and neurotoxic effects of lithium).
