Menatetrenone

Template:Short description Template:Cs1 config Template:Short description Template:Template other{{Infobox drug/maintenance categoriesTemplate:Yesno | drug_name = | INN = | _drugtype =

| _has_physiological_data= | _has_gene_therapy=

| vaccine_type= | mab_type= | _number_of_combo_chemicals= | _vaccine_data= | _mab_data= | _mab_vaccine_data= | _mab_other_data=31402CC1=C(C(=O)C2=CC=CC=C2C1=O)C/C=C(\C)/CC/C=C(\C)/CC/C=C(\C)/CCC=C(C)C1S/C31H40O2/c1-22(2)12-9-13-23(3)14-10-15-24(4)16-11-17-25(5)20-21-27-26(6)30(32)28-18-7-8-19-29(28)31(27)33/h7-8,12,14,16,18-20H,9-11,13,15,17,21H2,1-6H3/b23-14+,24-16+,25-20+DKHGMERMDICWDU-GHDNBGIDSA-NTemplate:StdinchiciteTemplate:Stdinchicite | _combo_data= | _physiological_data= | _clinical_data=Template:Drugs.com By mouthM05 | _legal_data=

| _other_data=2-methyl-3-[(2Z,6E,10E)-3,7,11,15-tetramethylhexadeca-2,6,10,14-tetraen-1-yl]naphthoquinone

| _image_0_or_2 = Menatetrenone.PNGMenatetrenone molecule spacefill.png | _image_LR =

| _datapage = Menatetrenone (data page) | _vaccine_target=_type_not_vaccine | _legal_all= | _ATC_prefix_supplemental=M05 | _has_EMA_link = | CAS_number=863-61-6 | PubChem=5282367 | ChemSpiderID=4445530 | ChEBI=78277 | ChEMBL= | DrugBank= | KEGG=D00100 | _hasInChI_or_Key=yes | UNII=27Y876D139 | _hasJmol02 = |_hasMultipleCASnumbers = |_hasMultiplePubChemCIDs = |_hasMultipleChEBIs =

| _countSecondIDs= | _countIndexlabels= | _trackListSortletter= |QID = |QID2 = |Verifiedfields=changed |Watchedfields=changed |verifiedrevid=451239229}}

Menatetrenone (INN), also known as menaquinone-4 (MK-4), is one of the nine forms of vitamin K₂.

Biology

MK-4 is the major form of Vitamin K in vertebrate animals, including humans and common forms of meat animals. It is produced via conversion of vitamin K₁ in the body, specifically in the testes, pancreas and arterial walls. The conversion is not dependent on gut bacteria, occurring in germ-free rats and in parenterally-administered K₁ in rats. Tissues that accumulate high amounts of MK-4 have a capacity to convert up to 90% of the available K₁ into MK-4.

K₁ is converted to MK-4 in three steps:

• Removal of the phytyl tail to form menadione (K3; unknown enzyme);
• Reduction of menadione to menadiol (likely NQO1);
• Attachment of GGPP tail to form menaquinol-4, the reduced form of MK-4 (UBIAD1)

The second and third steps are known to happen in target tissue. The first step is proposed to happen mainly in the intestines.

As a medication

Menatetrenone is approved in Japan for second-line treatment of postmenopausal osteoporosis. Evidence is restricted to small-scale RCTs; the minimum effective dose (for bone mass parameters) is 45 mg, much higher than the Daily Value for vitamin K (80 μg).

Bioavailbility and dose

420 μg of oral MK-4, in a single-dose or spread out over 7 days, does not cause detectable changes in serum MK-4 level in healthy women, whereas MK-7 produces the expected increases in MK-7 levels.

The minimum effective oral dose to change serum osteocalcin levels is 1500 μg/d, where as oral MK-7 is effective on this parameter at 45 μg/d, a level more in line with nutritional intake. In addition, rat studies show that oral MK-7 is better at increasing extrahepatic tissue levels of MK-4 than oral MK-4.