Pharmacology for Anaesthesia and Intensive Care

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Section IBasic principles

Papaverine:Heterocyclic ring structure related to opioids and found with

morphine in opium. Two papaverine-like ring structures are found in

bis-benzylisoquinoliniums. Papaverine is a smooth muscle relaxant.

Phenanthrene:Apolycyclic carbon ring structure related to morphine.

Phencyclidine:Acyclic hexacarbon with a phenolic substituent group. The

underlying structure of ketamine.

Phenyl:Phenol is hydroxylated benzene, C 6 H 5 OH. A phenyl group is –C 6 H 4 OH.

Commonly part of drug structures, for example, paracetamol, propofol and

edrophonium, and as a substituent, for example, in phentolamine and fentanyl.

Phenol is water-soluble.

Piperazine:Heterocyclic ring containing two N atoms and4Catoms, C 4 H 10 N 2.

The N atoms are in opposition, that is, in the 1 and 4 positions. The –NH- groups

are bases, proton acceptors, so that pH and pKa will determine degree of

ionization and hence water solubility.