dirithromycin dirithromycin dirithromycin is a macrolide glycopeptide antibiotic. dirithromycinclinical datatrade namesdynabacahfs/drugs.commicromedex detailed consumer informationmedlineplusa604026license data us fda: clarithromycin pregnancycategory b routes ofadministrationoralatc codej01fa13 (who) pharmacokinetic databioavailability10%protein binding15 to 30%metabolismhyrolized to erythromycyclamine in 1.5 hoursidentifiers iupac name (2r,3r,6r,7s,8s,9r,10r,12r,13s,15r,17s)-9--3-ethyl-2,10-dihydroxy-7--15--2,6,8,10,12,17-hexamethyl-4,16-dioxa-14-azabicycloheptadecan-5-one cas number62013-04-1 ypubchem cid6917067drugbankdb00954 ychemspider5292341 yunii1801d76stlkeggd03865 ychebichebi:474014 nchemblchembl3039471 ncomptox dashboard (epa)dtxsid7048956 echa infocard100.152.704 chemical and physical dataformulac42h78n2o14molar mass835.086 g·mol−13d model (jsmol)interactive imagemelting point186 to 189 °c (367 to 372 °f) (dec.) smiles o=c4o((o)(c)1o(n(1c)(c)c(o)(c)(o2o(c)c(n(c)c)2o)((o3o(c)(o)(oc)(c)c3)4c)c)coccoc)cc inchi inchi=1s/c42h78n2o14/c1-15-29-42(10,49)37-24(4)32(43-30(56-37)21-52-17-16-50-13)22(2)19-40(8,48)36(58-39-33(45)28(44(11)12)18-23(3)53-39)25(5)34(26(6)38(47)55-29)57-31-20-41(9,51-14)35(46)27(7)54-31/h22-37,39,43,45-46,48-49h,15-21h2,1-14h3/t22-,23-,24+,25+,26-,27+,28+,29-,30-,31+,32+,33-,34+,35+,36-,37+,39+,40-,41-,42-/m1/s1 ykey:wlohnssyaxhwnr-nxpdykkbsa-n y ny (what is this?) (verify) dirithromycin (dynabac) is a more lipid-soluble prodrug derivative of 9s-erythromycyclamine prepared by condensation of the latter with 2-(2-methoxyethoxy)acetaldehyde. the 9n, 11o-oxazine ring thus formed is a hemi-aminal that is unstable under both acidic and alkaline aqueous conditions and undergoes spontaneous hydrolysis to form erythromycyclamine. erythromycyclamine is a semisynthetic derivative of erythromycin in which the 9-ketogroup of the erythronolide ring has been converted to an amino group. erythromycyclamine retains the antibacterial properties of erythromycin oral administration. the prodrug, dirithromycin, is provided as enteric coated tablets to protect it from acid catalyzed hydrolysis in the stomach. orally administered dirithromycin is absorbed rapidly into the plasma, largely from the small intestine. spontaneous hydrolysis to erythromycyclamine occurs in the plasma. oral bioavailability is estimated to be about 10%, but food does not affect absorption of the prodrug. discontinuation dirithromycin is no longer available in the united states. since the production of dirithromycin is discontinued in the u.s, national institutes of health recommend that people taking dirithromycin should consult their physicians to discuss switching to another treatment. however, dirithromycin is still available in many european countries.