Nitrendipine is a

dihydropyridine 1,4-Dihydropyridine (DHP) is an organic compound with the formula CH2(CH=CH)2NH. The parent compound is uncommon, but derivatives of 1,4-dihydropyridine are important commercially and biologically. The pervasive cofactors NADH and NADPH are deriv ...

calcium channel blocker Calcium channel blockers (CCB), calcium channel antagonists or calcium antagonists are a group of medications that disrupt the movement of calcium () through calcium channels. Calcium channel blockers are used as antihypertensive drugs, i.e., as ...

. It is used in the treatment of primary (essential) hypertension to decrease blood pressure and can reduce the

cardiotoxicity Cardiotoxicity is the occurrence of heart dysfunction as electric or muscle damage, resulting in heart toxicity. This can cause heart failure, arrhythmia, myocarditis, and cardiomyopathy in patients. Some effects are reversible, while in others, p ...

of cocaine. It was patented in 1971 and approved for medical use in 1985.

Medical uses

Nitrendipine is given to hypertensive individuals in 20 mg oral tablets every day. This amount is effective in reducing blood pressure by 15–20% within 1–2 hours of administration. With long-term treatments, the dosage may rise to as much as 40 mg/day; in elderly individuals, a lower dosage of up to 5 mg/day may be equally effective (this reduction in drug amount is attributed to decreased liver function or “first pass” metabolism). Once digested, nitrendipine is absorbed into the blood and binds to plasma proteins. The majority (98%) is bound to plasma proteins and 70-80% of its inactive polar metabolites are also bound to plasma proteins. Following

hepatic metabolism The liver is a major metabolic organ exclusively found in vertebrates, which performs many essential biological functions such as detoxification of the organism, and the synthesis of various proteins and various other biochemicals necessary for ...

, 80% of the 20 mg dose can be recovered in the first 96 hours as inactive polar metabolites. The specific

volume of distribution In pharmacology, the volume of distribution (VD, also known as apparent volume of distribution, literally, ''volume of dilution'') is the theoretical volume that would be necessary to contain the total amount of an administered drug at the same c ...

of the drug is 2-6 L/kg. In terms of drug half-life, nitrendipine has a

half-life Half-life is a mathematical and scientific description of exponential or gradual decay. Half-life, half life or halflife may also refer to: Film * Half-Life (film), ''Half-Life'' (film), a 2008 independent film by Jennifer Phang * ''Half Life: ...

of 12–24 hours. The reported side effects include: headache, flushing, edema and palpitations. These side effects can all be attributed to the

vasodilation Vasodilation, also known as vasorelaxation, is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. Blood vessel wa ...

effect of this drug.

Mechanism of action

Once nitrendipine is ingested, it is absorbed by the gut and metabolized by the liver before it goes into the systemic circulation and reaches the cells of the

smooth muscles Smooth muscle is one of the three major types of vertebrate muscle tissue, the others being skeletal and cardiac muscle. It can also be found in invertebrates and is controlled by the autonomic nervous system. It is non- striated, so-called becau ...

and cardiac muscle cells. It binds more effectively with

L-type calcium channel The L-type calcium channel (also known as the dihydropyridine channel, or DHP channel) is part of the high-voltage activated family of voltage-dependent calcium channel. "L" stands for long-lasting referring to the length of activation. This ...

s in smooth muscle cells because of its lower

resting membrane potential The relatively static membrane potential of quiescent cells is called the resting membrane potential (or resting voltage), as opposed to the specific dynamic electrochemical phenomena called action potential and graded membrane potential. The re ...

. The nitrendipine diffuses into the membrane and binds to its high affinity binding site on the inactivated L-type calcium channel that's located in between each of the 4 intermembrane components of the α1 subunit. The exact mechanism of action of nitrendipine is unknown, but it is believed to have important

tyrosine -Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a conditionally essential amino acid with a polar side group. The word "tyrosine" is ...

and

threonine Threonine (symbol Thr or T) is an amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH form when dissolved in water), a carboxyl group (which is in the deprotonated −COO− ...

residues in its binding pocket and its binding interferes with the voltage sensor and gating mechanism of the channel. Thought to have a domain-interface model of binding. In hypertension, the binding of nitrendipine causes a decrease in the probability of open L-type calcium channels and reduces the influx of calcium. The reduced levels of calcium prevent smooth muscle contraction within these muscle cells. Prevention of muscle contraction enables smooth muscle dilation. Dilation of the vasculature reduces

total peripheral resistance Vascular resistance is the resistance that must be overcome for blood to flow through the circulatory system. The resistance offered by the systemic circulation is known as the systemic vascular resistance or may sometimes be called by another ter ...

, which decreases the workload on the heart and prevents scarring of the heart or heart failure. Nitrendipine has additionally been found to act as an

antagonist An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.mineralocorticoid receptor The mineralocorticoid receptor (or MR, MLR, MCR), also known as the aldosterone receptor or nuclear receptor subfamily 3, group C, member 2, (NR3C2) is a protein that in humans is encoded by the ''NR3C2'' gene that is located on chromosome 4q31 ...

, or as an

antimineralocorticoid A mineralocorticoid receptor antagonist (MRA or MCRA) or aldosterone antagonist, is a diuretic drug which receptor antagonist, antagonizes the action of aldosterone at mineralocorticoid receptors. This group of drugs is often used as adjunctive t ...

Stereochemistry

Nitrendipine contains a stereocenter and can exist as either of two

enantiomer In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, antipode, or optical antipode, is one of a pair of molecular entities whi ...

s. The pharmaceutical drug is a

racemate In chemistry, a racemic mixture or racemate () is a mixture that has equal amounts (50:50) of left- and right-handed enantiomers of a chiral molecule or salt. Racemic mixtures are rare in nature, but many compounds are produced industrially as r ...

, an equal mixture of (''R'')- and the (''S'')-forms.Rote Liste Service GmbH (Hrsg.): ''Rote Liste 2017 – Arzneimittelverzeichnis für Deutschland (einschließlich EU-Zulassungen und bestimmter Medizinprodukte)''. Rote Liste Service GmbH, Frankfurt/Main, 2017, Aufl. 57, , S. 204.

References

{{Mineralocorticoidics Antimineralocorticoids Calcium channel blockers Dihydropyridines 3-Nitrophenyl compounds Carboxylate esters Glycine receptor antagonists Methyl esters Ethyl esters