Clinical data
AHFS/ International Drug Names
MedlinePlus a606008
  • AU: A
  • US: C (Risk not ruled out)
Routes of
Oral; injection (intramuscular or slow intravenous); topical (ophthalmic/nasal solution)
ATC code
Pharmacokinetic data
Metabolism Hepatic hydroxylation, demethylation and glucuronidation
Excretion Renal
CAS Number
PubChem CID
CompTox Dashboard (EPA)
ECHA InfoCard 100.001.506 Edit this at Wikidata
Chemical and physical data
Formula C16H20N2
Molar mass 240.350 g·mol−1
3D model (JSmol)

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.

It was patented in 1948.[1] 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[edit]

Pheniramine may cause drowsiness or bradycardia, and over-dosage may lead to sleep disorders.[citation needed]

Overdose may lead to seizures, especially in combination with alcohol.[citation needed]

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.[citation needed]

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.[citation needed]

Chemical relatives[edit]

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 triprolidine. Similar molecules include diphenhydramine, doxylamine, and tripelennamine.


Pheniramine contains a stereocenter and consists of two enantiomers. This is a racemate, a 1: 1 mixture of (R) and the (S) forms:[2]

Enantiomers of pheniramine
(R)-Pheniramin Structural Formula V1.svg
CAS-Nummer: 56141-72-1
(S)-Pheniramin Structural Formula V1.svg
CAS-Nummer: 23201-92-5

See also[edit]


  1. ^ Fischer, Jnos; Ganellin, C. Robin (2006). Analogue-based Drug Discovery. John Wiley & Sons. p. 546. ISBN 9783527607495.
  2. ^ F. v. Bruchhausen, G. Dannhardt, S. Ebel, A. W. Frahm, E. Hackenthal, U. Holzgrabe (Hrsg.): Hagers Handbuch der Pharmazeutischen Praxis: Band 9: Stoffe P-Z, Springer Verlag, Berlin, Aufl. 5, 2014, S. 121, ISBN 978-3-642-63389-8.

External links[edit]