pheniramine pheniramine pheniramine (trade name avil among others) is an antihistamine with anticholinergic properties used to treat allergic conditions such as hay fever or urticaria. it has relatively strong sedative effects, and may sometimes be used off-label as an over-the-counter sleeping pill in a similar manner to other sedating antihistamines such as diphenhydramine. pheniramine is also commonly found in eyedrops used for the treatment of allergic conjunctivitis. pheniramineclinical dataahfs/drugs.cominternational drug namesmedlineplusa606008pregnancycategory au: a routes ofadministrationoral; injection (intramuscular or slow intravenous); topical (ophthalmic/nasal solution)atc coded04aa16 (who) r06ab05 (who)pharmacokinetic datametabolismhepatic hydroxylation, demethylation and glucuronidationelimination half-life16 - 19 hrs (oral), 8 - 7 hrs (i.v.)excretionrenalidentifiers iupac name n,n-dimethyl-3-phenyl-3-pyridin-2-yl-propan-1-amine cas number86-21-5 ypubchem cid4761iuphar/bps7267drugbankdb01620 ychemspider4597 yunii134fm9zz6mkeggd08355 ychemblchembl1193 ycomptox dashboard (epa)dtxsid0023454 echa infocard100.001.506 chemical and physical dataformulac16h20n2molar mass240.350 g·mol−13d model (jsmol)interactive image smiles n1ccccc1c(c2ccccc2)ccn(c)c inchi inchi=1s/c16h20n2/c1-18(2)13-11-15(14-8-4-3-5-9-14)16-10-6-7-12-17-16/h3-10,12,15h,11,13h2,1-2h3 ykey:ijhnshdbirrjrn-uhfffaoysa-n y (verify) it was patented in 1948. pheniramine is generally sold in combination with other medications, rather than as a stand-alone drug, although some formulations are available containing pheniramine by itself. side effects pheniramine may cause drowsiness or tachycardia, and over-dosage may lead to sleep disorders. overdose may lead to seizures, especially in combination with alcohol. people combining with cortisol in the long term should avoid pheniramine as it may decrease levels of adrenaline (epinephrine) which may lead to loss of consciousness. pheniramine is a deliriant (hallucinogen) in toxic doses. recreational use of coricidin for the dissociative (hallucinogenic) effect of its dextromethorphan is hazardous because it also contains chlorpheniramine. chemical relatives halogenation of pheniramine increases its potency 20-fold. halogenated derivatives of pheniramine include chlorphenamine, brompheniramine, dexchlorpheniramine, dexbrompheniramine, and zimelidine. two other halogenated derivatives, fluorpheniramine and iodopheniramine, are currently in use for research on combination therapies for malaria and some cancers. other analogs include diphenhydramine, and doxylamine. stereoisomerism pheniramine contains a stereocenter and can exists as either of two enantiomers. the pharmaceutical drug is a racemate, an equal mixture of the (r)- and (s)-forms. enantiomers of pheniramine (r)-pheniramine cas number: 56141-72-1 (s)-pheniramine cas number: 23201-92-5