Mequitazine

Mequitazine

Clinical data
Trade names	Primalan
AHFS/Drugs.com	International Drug Names
ATC code	R06AD07 (WHO)
Legal status
Legal status	EU: Rx-only
Identifiers
IUPAC name 10-(1-Azabicyclo[2.2.2]octan-3-ylmethyl)phenothiazine
CAS Number	29216-28-2 Y
PubChem CID	4066
DrugBank	DB01071 N
ChemSpider	3926 N
UNII	Y463242LY2
KEGG	D01324 Y
E number	{{#property:P628}}
CompTox Dashboard (EPA)	{{#property:P3117}}
ECHA InfoCard	{{#property:P2566}}
Chemical and physical data
Formula	C20H22N2S
Molar mass	322.47 g·mol−1
3D 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,9-14H2 Key:HOKDBMAJZXIPGC-UHFFFAOYSA-N
NY (what is this?)  (verify)

Mequitazine (trade name Primalan) is an H₁ antagonist and anticholinergic of the phenothiazine chemical class. It is used to treat allergies and rhinitis.

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: