Aliskiren is a drug that acts as a renin inhibitor (renin inhibitor) for the treatment of arterial hypertension. It is sold under various trade names as a monotherapy as well as a combination preparation and is available by prescription. The drug was approved in the United States in March 2007, in Switzerland in June, and in Germany in August.
What is aliskiren?
Aliskiren is a drug used to regulate high blood pressure. Aliskiren is a drug used to regulate high blood pressure. It inhibits the enzyme renin, thereby interfering with the renin-angiotensin-aldosterone system that regulates blood pressure. Among the known renin inhibitors, aliskiren is the only drug approved to date. Two other preparations – zankiren and remikiren – are still awaiting approval. The first renin inhibitors were antibodies that directly targeted the enzyme renin. What lowered blood pressure in animal studies was not developed further, especially since these first renin inhibitors could only be administered by injection. Through further intermediate steps, aliskiren was finally ready for the market, and it fulfilled expectations well.
Pharmacologic Action
In its intervention in the renin-angiotension-aldosterone system, aliskiren binds the enzyme renin, triggering subsequent biochemical processes. Renin as a protease, a protein-cleaving enzyme, converts angiotensinogen into angiotensin I, which in turn is converted into angiotensin II by an angiotensin-converting enzyme. This can then independently trigger vasoconstriction and cause an additional release of aldosterone. This results in a higher reabsorption of sodium ions and water in the renal collecting tubes, which causes blood pressure to rise. Aliskiren binds renin and thus effectively prevents its complex function. The processes described above do not occur and blood pressure may decrease. Aliskiren is taken orally once daily. Since it affects blood pressure by releasing renin, it takes about one to two weeks after starting treatment before the first measurable therapeutic success is achieved. Aliskiren is almost always given in combination with other antihypertensives. These may be diuretics prescribed for hypertension treatment, for example.
Medical use and application
For the treatment of hypertension, the renin inhibitor aliskiren is a novel and effective agent. The producer Novartis even speaks of “a new dimension in hypertension treatment.” Since the renin inhibitor aliskiren intervenes very early in the renin-angiotensin-aldosterone system, it completely stops the production of angiotensin II. This distinguishes the drug from other drugs that have often been used in the past, such as ACE inhibitors. These only inhibit the ACE (angiotensin-converting enzyme) that converts angiotensin I to angiotensin II, but not the enzyme chymase. Thus, the renin-angiotensin system is only incompletely inhibited. In addition, renin inhibitors such as aliskiren do not slow the breakdown of bradykinin, an inflammatory mediator. When ACE inhibitors are used, the bradykinin that then exists causes the well-known kinin cough, the typical side effect of ACE inhibitor medication. Nevertheless, it remains to be seen whether the still new drug aliskiren is therapeutically superior to the more conventional ACE inhibitors. When taking aliskiren, it should be noted that an increased fat content in the diet negatively affects the absorption of the active ingredient. Therefore, aliskiren is not always so easy to control in its individual degree of effectiveness. In addition, there is the generally poor absorption of renin inhibitors, which is often less than 2% with oral medication. Due to the lack of long-term results, the administration of aliskiren to children and adolescents is not recommended. Likewise, pregnant and lactating women should refrain.
Risks and Side Effects
Therapy with aliskiren may cause undesirable side effects:
- Nausea, vomiting, and diarrhea
- Upper respiratory tract infections
- Cough
- Fatigue
- Headache
- Back pain
- Allergies
In the case of numerous chronic or acute diseases and with appropriate medication, a detailed consultative doctor-patient discussion is essential before starting therapy with Aliskiren. Contraindicated is the administration of aliskiren in the following diseases:
- Angioedema
- Diabetes mellitus
- impaired renal function
Also contraindicated is aliskiren with medication with:
- Ciclosporin
- Itraconazole
- Quinidine
A responsible physician will therefore monitor blood pressure, electrolyte levels, laboratory values, and renal functions regularly in advance of planned therapy with aliskiren and, if necessary, during the treatment period.
