Losartan

verifiedrevid	458612349
alt	Skeletal formula
width	200
image2	Losartan-from-xtal-3D-bs-17.png
alt2	Ball-and-stick model
tradename	Cozaar, others
medlineplus	a695008
dailymedid	Losartan
pregnancy au	D
routes of administration	By mouth
class	Angiotensin II receptor antagonist
atc prefix	C09
atc suffix	CA01
legal us	Rx-only
legal us comment	‡R1R‡
legal status	Rx-only
bioavailability	25–35%
protein bound	99.7% (primarily albumin)
metabolism	Liver (CYP2C9, CYP3A4)
elimination half-life	1.5–2 hours
excretion	Kidney 13–25%, bile duct 50–60%
cas number	114798-26-4
pubchem	3961
iuphar ligand	590
drugbank	DB00678
chemspiderid	3824
unii	JMS50MPO89
kegg	D08146
chebi	6541
chembl	191
iupac name	(2-butyl-4-chloro-1-{[2'-(2H-tetrazol-5-yl)biphenyl-4-yl]methyl}-1H-imidazol-5-yl)methanol
c	22
h	23
cl	1
n	6
o	1
smiles	CCCCc1nc(Cl)c(CO)n1Cc1ccc(-c2ccccc2-c2nn[nH]n2)cc1
stdinchi	1S/C22H23ClN6O/c1-2-3-8-20-24-21(23)19(14-30)29(20)13-15-9-11-16(12-10-15)17-6-4-5-7-18(17)22-25-27-28-26-22/h4-7,9-12,30H,2-3,8,13-14H2,1H3,(H,25,26,27,28)
stdinchikey	PSIFNNKUMBGKDQ-UHFFFAOYSA-N

Losartan, sold under the brand name Cozaar among others, is a medication used to treat high blood pressure (hypertension). It is in the angiotensin receptor blocker (ARB) family of medication, and is considered protective of the kidneys. Besides hypertension, it is also used in diabetic kidney disease, heart failure, and left ventricular enlargement. It comes as a tablet that is taken by mouth. It may be used alone or in addition to other blood pressure medication. Up to six weeks may be required for the full effects to occur.

Common adverse effects include muscle cramps, stuffy nose, dizziness, cough, high blood potassium, and anemia. Severe adverse effects may include angioedema, low blood pressure, and kidney problems. Use during pregnancy may result in harm to the baby. Use is not recommended during breastfeeding.[2] It works by blocking angiotensin II.

Losartan was patented in 1986, and approved for medical use in the United States in 1995.[3][4]

Mechanism of action

Losartan is a selective, competitive angiotensin II receptor type 1 (AT1) antagonist, reducing the end organ responses to angiotensin II. Losartan administration results in a decrease in total peripheral resistance (afterload) and cardiac venous return (preload). All of the physiological effects of angiotensin II, including the release of aldosterone, are antagonized in the presence of losartan. Reduction in blood pressure occurs independently of the status of the renin–angiotensin system. As a result of losartan dosing, plasma renin activity increases due to the removal of the angiotensin II feedback. Renin is released from the kidneys when there is reduced renal arterial pressure, sympathetic activation, or increased sodium delivery to the distal renal tubule.[33] Renin then acts by converting angiotensinogen to angiotensin I; angiotensin-converting enzyme (ACE) converts angiotensin I to angiotensin II; angiotensin II causes vasoconstriction and aldosterone release.[33] Aldosterone serves to retain sodium from the distal renal tubule. Sodium retention ultimately results in increased blood pressure.[34] Therefore, the use of angiotensin II receptor antagonists like losartan results in blocking the downstream effect of renin, and angiotensin II, and ultimately decreasing blood pressure.

Angiotensin II receptor antagonists include losartan, valsartan, azilsartan, candesartan, eprosartan, irbesartan, olmesartan, and telmisartan. They all have the same mechanism of action and potentially inhibit the actions of angiotensin better than ACE inhibitors, such as lisinopril, because other enzymes than ACE have the capability of producing angiotensin II.[33]

Losartan is a uricosuric. As a specific inhibitor of the urate transporter 1 (SLC22A12, URAT1), losartan blocks the uptake of uric acid into cells, thus leaving more available in the bloodstream to be filtered and excreted by the kidneys.[35] Because losartan can cause hyperkalemia, individuals should not use potassium supplements or salt substitutes containing potassium without appropriate monitoring by a physician.[36]

Losartan

Chemistry

Medical uses

Adverse effects

Pregnancy

Overdose

Mechanism of action

Pharmacokinetics

History

Further reading

External links

References

Interactions

Contamination