How nitrendipine works
Calcium channel blockers such as nitrendipine block the influx of calcium into the muscle cells of the blood vessel walls. As a result, the walls relax and widen – blood pressure drops.
Blood pressure is significantly influenced by the diameter of the blood vessels. When the smooth muscle in the walls of the vessels contracts, narrowing the vessels, blood pressure rises. When the wall muscles relax so that the vessels widen, it falls.
Absorption, degradation and excretion
Nitrendipine is taken by mouth (orally) and is very well absorbed (reabsorbed) into the blood. Maximum drug levels in the blood are reached after one to three hours.
When the active ingredient is taken as a tablet, the effect sets in after 20 to 30 minutes. Nitrendipine is metabolized in the liver by the enzyme CYP3A4 and subsequently excreted mainly via the kidneys in the urine, and to a small extent also in the stool.
When is nitrendipine used?
Nitrendipine tablets are used to treat high blood pressure (hypertension).
In the past, vials containing a nitrendipine solution were also available in Germany – for use in a hypertensive emergency (a sharp, sudden rise in blood pressure with a risk to life). However, their distribution was discontinued by the manufacturing company in 2021.
How nitrendipine is used
What are the side effects of nitrendipine?
Very common side effects of nitrendipine – as a result of vasodilatation – are headache, redness of the skin with a feeling of warmth, and palpitations (applies especially to vials).
Very rare side effects of nitrendipine include heart attack, gum growth (gingival hyperplasia), changes in various blood counts (such as white blood cell deficiency), and in men, enlargement of the mammary glands (gynecomastia).
If you suffer from severe side effects or symptoms not mentioned above, please consult your doctor.
What should be considered while taking nitrendipine?
Contraindications
Other contraindications include:
- Cardiovascular shock
- heart attack in the past four weeks
- unstable angina pectoris
- decompensated cardiac insufficiency (here all possibilities of the body to compensate for the cardiac insufficiency are exhausted, so that symptoms such as shortness of breath occur even at rest)
- simultaneous use of rifampicin (antibiotic)
Drug Interactions
If nitrendipine is used together with other antihypertensives, the blood pressure-lowering effect is increased.
The antihypertensive drug may increase the blood level of the heart drug digoxin, so its dose may need to be reduced.
Several drugs may reduce the effect of nitrendipine when used concomitantly, such as the anticonvulsants carbamazepine, phenytoin, and phenobarbital.
Grapefruit juice should be avoided during therapy with nitrendipine. This is because grapefruit juice is a potent inhibitor of the enzyme CYP3A4 and can therefore slow down the excretion of nitrendipine – the result would be an increased, unpredictable drop in blood pressure.
Age Limitation
The safety and efficacy of nitrendipine in children and adolescents under 18 years of age have not been established.
Pregnancy and Lactation
However, clinical experience to date has not shown an increased risk of malformation in unborn children whose mothers have taken nitrendipine. Therefore, if better studied drugs are not an option, therapy with nitrendipine in pregnancy is probably acceptable.
The drugs of choice for lowering blood pressure during pregnancy and lactation are alpha-methyldopa and metoprolol. If needed, the better-studied calcium channel blocker nifedipine is used primarily.
How to obtain medication with nitrendipine
Nitrendipine requires a prescription in Germany and Austria and is therefore only available from pharmacies on presentation of a doctor’s prescription. In Switzerland, medicines containing the active ingredient are no longer available.
