How candesartan works
Like all sartans, the active ingredient candesartan interferes with the renin-angiotensin-aldosterone system (RAAS) of the human body. This regulates fluid and electrolyte balance and thus also blood pressure. To understand how sartans work, it is sufficient to look at a small section of this hormonal system.
Sartans (also known as angiotensin II receptor antagonists) block the docking site (receptor) of the hormone angiotensin II so that it can no longer exert its effect. Normally, the hormone causes vasoconstriction, reduced renal blood flow and increased reabsorption of sodium ions and thus water in the kidneys. In sum, this leads to an increase in blood pressure.
The name “angiotensin II” suggests that there is also an angiotensin I. This hormone is formed from angiotensinogen – a step that can also be blocked by drugs in order to lower blood pressure. The preparations used for this purpose are called ACE inhibitors.
Candesartan cilexetil
In practice, the precursor candesartan cilexetil is used instead of candesartan. This is much better absorbed in the intestine and is then rapidly and completely converted in the body (already in the intestinal wall) to the actual active ingredient candesartan. After taking one tablet, the highest level of active ingredient in the blood is reached after about three to four hours.
Candesartan is hardly metabolized in the body. About nine hours after ingestion, half of the active ingredient is excreted unchanged in the urine (about one-third) and half is excreted in the stool via the bile (about two-thirds).
When is candesartan used?
Candesartan is primarily used to treat high blood pressure (hypertension) and chronic heart failure (chronic heart failure), especially when ACE inhibitors are not tolerated.
Candesartan is used on a long-term basis to achieve a safe and stable reduction in blood pressure.
How Candesartan is used
The combination of candesartan and other blood pressure-regulating drugs (such as the dehydrating agent hydrochlorothiazide – HCT) can result in a mutual enhancement of effect (synergistic effect), which is particularly desirable in the case of severely elevated blood pressure. Corresponding combination preparations are also available on the German market.
What are the side effects of candesartan?
According to studies, patients receiving candesartan hardly experienced any more side effects than subjects treated with a placebo. Common side effects (one in ten to one hundred people treated) included respiratory infections, dizziness, headache, low blood pressure, impaired kidney function, and high blood potassium levels.
The suspicion that candesartan may cause cancer has now been thoroughly investigated and refuted several times in larger studies and meta-analyses (joint evaluation of several studies).
The “first-dose hypotension” – a sharp drop in blood pressure after taking the drug for the first time – that occurs with other blood pressure medications does not occur with candesartan. The same applies to the “rebound effect”. This refers to an intensification of the original symptoms (in this case high blood pressure) after discontinuation of the drug.
What should be taken into account when taking Candesartan?
During treatment with candesartan, non-steroidal anti-inflammatory drugs (NSAIDs) such as acetylsalicylic acid or ibuprofen should not be taken without medical consultation. Otherwise, kidney function may deteriorate and thus weaken the antihypertensive effect of the drug. Paracetamol can be used as an alternative painkiller.
Candesartan is contraindicated in severe liver disease and biliary obstruction. In case of kidney disease, kidney function and blood potassium levels must be monitored regularly.
Pregnancy and lactation
Candesartan should not be taken during pregnancy as it has fertility damaging properties. During lactation, preference should be given to better studied antihypertensive drugs.
Children and adolescents
Physicians may also use candesartan in children and adolescents six years of age and older to treat high blood pressure. In younger patients, however, safety and efficacy have not yet been sufficiently proven. In addition, there are no data (yet) for children and adolescents with heart failure. Candesartan is contraindicated in children under one year of age.
How to obtain medicines containing candesartan
The active ingredient candesartan is available by prescription in Germany, Austria and Switzerland in any dosage and can be obtained from pharmacies on presentation of a prescription.
In 1982, scientists discovered several inhibitors of the blood pressure-increasing effect of angiotensin II. In the years that followed, their structure was further improved by means of computer calculations, laboratory tests and animal experiments. As a result, the active ingredient losartan, the first representative of the new group of active ingredients known as sartans, was developed in 1986.
It was launched on the market in the United States and Germany in 1995. Later, other sartans with a longer residence time and lower metabolism in the body were developed. One of these was candesartan. It was approved in Germany in 1997.
