A major contributor to this article appears to have a close connection with its subject.(November 2016) |
Clinical data | |
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Routes of administration | Oral |
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Pharmacokinetic data | |
Bioavailability | 33% |
Protein binding | Angiotensin II Subtype 2 Receptor |
Elimination half-life | 6-12 hr |
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ChemSpider | |
UNII | |
ChEBI | |
ChEMBL | |
Chemical and physical data | |
Formula | C32H29NO5 |
Molar mass | 507.586 g·mol−1 |
3D model (JSmol) | |
Specific rotation | + |
Density | 1.256±0.06 g/cm3 |
Boiling point | 745.3 ± 60.0 °C (1,373.5 ± 108.0 °F) |
Solubility in water | 14 mg/mL (20 °C) |
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EMA401 is a drug under development for the treatment of peripheral neuropathic pain. Trials were discontinued in 2015, with new trials scheduled to begin March, 2018. [1] It was initially established as a potential drug option for patients suffering pain caused by postherpetic neuralgia. [2] It may also be useful for treating various types of chronic neuropathic pain [3] EMA401 has shown efficacy in preclinical models of shingles, diabetes, osteoarthritis, HIV and chemotherapy. [4] [5] [6] [7] EMA401 is a competitive antagonist of angiotensin II type 2 receptor (AT2R) being developed by the Australian biotechnology company Spinifex Pharmaceuticals. EMA401 target angiotensin II type 2 receptors, which may have importance for painful sensitisation. [8]
Angiotensin II is an octapeptide hormone central to the renin-angiotensin system. It regulates blood pressure control, water fluid homeostasis, and neuronal excitability. [9] [10] [11] [12] Receptor agonists and antagonist of angiotensin II receptors that target various parts of the complicated renin-angiotensin system were developed to increase knowledge of the renin-angiotensin system and aid the development of antihypertensive drug candidates. [13] [14] These investigations led to the discovery of two subtypes of membrane bound G protein-coupled angiotensin receptors within the renin-angiotensin system with vastly different functions: angiotensin II type 1 receptors (AT1R) and angiotensin II type 2 receptors (AT2R). AT1R is the receptor subtype that was found to be mainly responsible for blood pressure, water fluid regulation, and other classical known physiological actions of angiotensin II on the renin-angiotensin system. [15]
Phase I clinical trial have indicated that doses of EMA401 up to 400 mg are safe in humans. [16] Spinifex Pharmaceuticals reported the results of a phase 2 randomised placebo controlled - clinical trial results in which 183 patients with postherpetic neuralgia received either oral EMA401 or placebo for 28 days. [17] Those assigned to EMA401 reported significantly less pain associated with post-herpetic neuralgia although the improvement was modest (6.9% better than placebo on a ten point pain scale). There was no evidence of any serious side effects caused by EMA401. Spinifex Pharmaceuticals plans to proceed with larger phase II clinical trial to test higher doses for longer periods of time. A nonrandomized Phase 2 study of EMA401 for the treatment of pain in patients with chemotherapy-induced peripheral neuropathy was approved and is currently underway.
Angiotensin II (AngII) is an octapeptide that regulates blood pressure, controls water fluid balance, and pain perception. It activates two G protein-coupled receptors: angiotensin II type 1 receptors (AT1R) and angiotensin II type 2 receptors (AT2R). [18] AngII co-localized in neurons that express substance P and calcitonin gene-related peptide suggesting its presence in nociceptors (noxious-stimuli sensing neurons). EMA401 may alleviate pain and provides relief by blocking the AngII induced potentiation which is thought to be coupled to protein kinase A.
EMA401 is the sodium-salt form of (S)-2-(diphenylacetyl)-l,2,3,4-tetrahydro-6-methoxy-5-(phenylmethoxy)- 3-isoquinoline carboxylic acid. EMA401 dose of up to 400 mg was tested in healthy male adults without any major adverse effects.. [16] EMA401 has been administered orally at a standardized dose of 100 mg twice daily. EMA401 reaches a maximum plasma concentration of 1000 ug/L one-hour after administration of 100 mg of EMA401 in both men and women, as observed in a phase II trial. [19] EMA401 has an elimination half-life of 6 hours on day 1 of drug intake increasing to 12 hours by day seven of drug intake. Total plasma concentration of EMA401 is consistent over 28 days. A steady state of minimum drug plasma concentration is reached by the 8th day of being on the drug. EMA401 does not accumulate in the blood at presently administered doses. EMA401 does not cross the blood-brain barrier, therefore has little effect on the central nervous system. [20]
No serious adverse effects have been observed with EMA401 in early clinical trials but there is limited evidence [21] Slightly higher frequency of complaints such as pharyngitis, headaches and allergic dermatitis are reported by individuals taking EMA401. [16] Headache frequency was higher in patients receiving EMA401 over placebo in both phase 1 and phase 2 clinical trials for EMA401.
Angiotensin-converting-enzyme inhibitors are a class of medication used primarily for the treatment of high blood pressure and heart failure. This class of medicine works by causing relaxation of blood vessels as well as a decrease in blood volume, which leads to lower blood pressure and decreased oxygen demand from the heart.
The renin–angiotensin system (RAS), or renin–angiotensin–aldosterone system (RAAS), is a hormone system that regulates blood pressure, fluid and electrolyte balance, and systemic vascular resistance.
Antihypertensives are a class of drugs that are used to treat hypertension. Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke, heart failure, kidney failure and myocardial infarction. Evidence suggests that reduction of the blood pressure by 5 mmHg can decrease the risk of stroke by 34% and of ischaemic heart disease by 21%, and can reduce the likelihood of dementia, heart failure, and mortality from cardiovascular disease. There are many classes of antihypertensives, which lower blood pressure by different means. Among the most important and most widely used medications are thiazide diuretics, calcium channel blockers, ACE inhibitors, angiotensin II receptor antagonists (ARBs), and beta blockers.
Amlodipine, sold under the brand name Norvasc among others, is a calcium channel blocker medication used to treat high blood pressure, coronary artery disease (CAD) and variant angina. It is taken orally.
Angiotensin II receptor blockers (ARBs), formally angiotensin II receptor type 1 (AT1) antagonists, also known as angiotensin receptor blockers, angiotensin II receptor antagonists, or AT1 receptor antagonists, are a group of pharmaceuticals that bind to and inhibit the angiotensin II receptor type 1 (AT1) and thereby block the arteriolar contraction and sodium retention effects of renin–angiotensin system.
Postherpetic neuralgia (PHN) is neuropathic pain that occurs due to damage to a peripheral nerve caused by the reactivation of the varicella zoster virus. PHN is defined as pain in a dermatomal distribution that lasts for at least 90 days after an outbreak of herpes zoster. Several types of pain may occur with PHN including continuous burning pain, episodes of severe shooting or electric-like pain, and a heightened sensitivity to gentle touch which would not otherwise cause pain or to painful stimuli. Abnormal sensations and itching may also occur.
Ramipril, sold under the brand name Altace among others, is an ACE inhibitor type medication used to treat high blood pressure, heart failure, and diabetic kidney disease. It can also be used as a preventative medication in patients over 55 years old to reduce the risk of having a heart attack, stroke or cardiovascular death in patients shown to be at high risk, such as some diabetics and patients with vascular disease. It is a reasonable initial treatment for high blood pressure. It is taken by mouth.
Candesartan is an angiotensin receptor blocker used mainly for the treatment of high blood pressure and congestive heart failure. Candesartan has a very low maintenance dose. Like Olmesartan, the metabolism of the drug is unusual as it is a cascading prodrug. Candesartan has good bioavailibility and is the most potent by weight of the AT-1 receptor antagonists.
Telmisartan, sold under the brand name Micardis among others, is a medication used to treat high blood pressure, heart failure, and diabetic kidney disease. It is a reasonable initial treatment for high blood pressure. It is taken by mouth. Versions are available as the combination telmisartan/hydrochlorothiazide, telmisartan/cilnidipine and telmisartan/amlodipine.
Valsartan, sold under the brand name Diovan among others, is a medication used to treat high blood pressure, heart failure, and diabetic kidney disease. It belongs to a class of medications referred to as angiotensin II receptor blockers (ARBs). It is a reasonable initial treatment for high blood pressure. It is taken by mouth.
Olmesartan, sold under the brand name Benicar among others, is a medication used to treat high blood pressure (hypertension). It is taken by mouth. Versions are available as the combination olmesartan/hydrochlorothiazide and olmesartan/amlodipine.
Perindopril is a medication used to treat high blood pressure, heart failure, or stable coronary artery disease.
Aliskiren is the first in a class of drugs called direct renin inhibitors. It is used for essential (primary) hypertension. While used for high blood pressure, other better studied medications are typically recommended due to concerns of higher side effects and less evidence of benefit.
Atrasentan is an experimental drug that is being studied for the treatment of various types of cancer, including non-small cell lung cancer. It is also being investigated as a therapy for diabetic kidney disease.
Renin inhibitors are pharmaceutical drugs inhibiting the activity of renin that is responsible for hydrolyzing angiotensinogen to angiotensin I, which in turn reduces the formation of angiotensin II that facilitates blood pressure.
CYT006-AngQb was an investigational vaccine against angiotensin II, designed to lower blood pressure. It was somewhat effective in clinical trials, but less so than conventional drugs against hypertension.
The angiotensin receptor blockers (ARBs), also called angiotensin (AT1) receptor antagonists or sartans, are a group of antihypertensive drugs that act by blocking the effects of the hormone angiotensin II in the body, thereby lowering blood pressure. Their structure is similar to Ang II and they bind to Ang II receptors as inhibitors, e.g., [T24 from Rhys Healthcare].
Fimasartan is a non-peptide angiotensin II receptor antagonist (ARB) used for the treatment of hypertension and heart failure. Through oral administration, fimasartan blocks angiotensin II receptor type 1 (AT1 receptors), reducing pro-hypertensive actions of angiotensin II, such as systemic vasoconstriction and water retention by the kidneys. Concurrent administration of fimasartan with diuretic hydrochlorothiazide has shown to be safe in clinical trials. Fimasartan was approved for use in South Korea on September 9, 2010, and is available under the brand name Kanarb through Boryung Pharmaceuticals, who are presently seeking worldwide partnership.
Mirogabalin is a gabapentinoid medication developed by Daiichi Sankyo. Gabapentin and pregabalin are also members of this class. As a gabapentinoid, mirogabalin binds to the α2δ subunit of voltage-gated calcium channel, but with significantly higher potency than pregabalin. It has shown promising results in Phase II clinical trials for the treatment of diabetic peripheral neuropathic pain.
Finerenone, sold under the brand name Kerendia, is a medication used to reduce the risk of kidney function decline, kidney failure, cardiovascular death, non-fatal heart attacks, and hospitalization for heart failure in adults with chronic kidney disease associated with type 2 diabetes. Finerenone is a non-steroidal mineralocorticoid receptor antagonist (MRA). It is taken orally.