mequitazine mequitazine mequitazine (trade name primalan) is an h1 antagonist and anticholinergic of the phenothiazine chemical class. it is used to treat allergies and rhinitis. mequitazineclinical datatrade namesprimalanahfs/drugs.cominternational drug namesatc coder06ad07 (who) legal statuslegal status eu: rx-only identifiers iupac name 10-(1-azabicyclooctan-3-ylmethyl)phenothiazine cas number29216-28-2 ypubchem cid4066drugbankdb01071 nchemspider3926 nuniiy463242ly2keggd01324 ycomptox dashboard (epa)dtxsid8023262 echa infocard100.045.005 chemical and physical dataformulac20h22n2smolar mass322.47 g·mol−13d model (jsmol)interactive image smiles c1ccc2c(c1)sc1ccccc1n2cc1cn2ccc1cc2 inchi inchi=1s/c20h22n2s/c1-3-7-19-17(5-1)22(18-6-2-4-8-20(18)23-19)14-16-13-21-11-9-15(16)10-12-21/h1-8,15-16h,9-14h2key:hokdbmajzxipgc-uhfffaoysa-n ny (what is this?) (verify) it was patented in 1969 and came into medical use in 1976. contraindications severe liver disease; premature infants or full-term neonates. special precautions pregnancy, lactation; severe cardiovascular disorders; asthma; angle-closure glaucoma, urinary retention, prostatic hyperplasia, pyloroduodenal obstruction; renal and hepatic impairment; elderly, children; epilepsy. may impair ability to drive or operate machinery. adverse reactions cns depression including slight drowsiness to deep sleep, lassitude, dizziness, incoordination. headache, psychomotor impairment and antimuscarinic effects. rarely, rashes and hypersensitivity reactions, blood disorders, convulsions, sweating, myalgia, paraesthesias, extrapyramidal effects, tremor, confusion, sleep and gi disturbances, tinnitus, hypotension, hair loss. photosensitivity, jaundice. drug interactions enhances effects of cns depressants e.g. alcohol, barbiturates, hypnotics, opioid analgesics, anxiolytics and antipsychotics. can mask signs of ototoxicity caused by aminoglycosides. qt prolongation (which can lead to torsades de pointes arrhythmia) reported with spiramycin. synthesis same precursor as for quifenadine. note that the synthesis has changed over the years from the original. one route seems to involve a johnson–corey–chaykovsky reaction of the starting ketone, although another secondary route is also discussed. thieme prec: synthesis: patents: new patent (91%): na: