Parasympathomimetic drug

Source: Wikipedia, the free encyclopedia.

A parasympathomimetic drug, sometimes called a cholinomimetic drug

cholinergic receptor stimulating agent,[2] is a substance that stimulates the parasympathetic nervous system (PSNS).[3][2] These chemicals are also called cholinergic drugs because acetylcholine (ACh) is the neurotransmitter used by the PSNS.[1][4] Chemicals in this family can act either directly by stimulating the nicotinic or muscarinic receptors (thus mimicking acetylcholine), or indirectly by inhibiting cholinesterase, promoting acetylcholine release, or other mechanisms.[5] Common uses of parasympathomimetics include glaucoma, Sjögren syndrome and underactive bladder.[6]

Some

riot control agents such as tear gas, and insecticides such as diazinon
fall into this category.

Structure activity relationships for parasympathomimetic drugs[7]

For a cholinergic agent, the following criteria describe the structure activity relationship:

  1. Ing's Rule of 5: there should be no more than five atoms between the nitrogen and the terminal hydrogen for muscarinic (or cholinergic) activity;
  2. the molecule must possess a nitrogen atom capable of bearing a positive charge, preferably a quaternary ammonium salt;
  3. for maximum potency, the size of the alkyl groups substituted on the nitrogen should not exceed the size of a methyl group;
  4. the molecule should have an oxygen atom, preferably an ester-like oxygen capable of participating in a hydrogen bond;
  5. there should be a two-carbon unit between the oxygen atom and the nitrogen atom.

Pharmaceuticals/Supplements

Direct-acting

These act by stimulating the nicotinic or muscarinic receptors.

  • Choline esters
    • acetylcholine receptors
      )
    • M3 receptors
      )
    • nicotinic receptors
      )
    • muscarinic receptors
      )
  • Plant alkaloids

Indirect-acting

Indirect acting parasympathomimetic substances may be either reversible cholinesterase inhibitors, irreversible cholinesterase inhibitors or substances that promote ACh release or

anti-adrenergics. The latter inhibits the antagonistic system, the sympathetic nervous system
.

See also

References

  1. ^
    OCLC 958121223
    .
  2. ^
    ISBN 978-0-7020-5554-6
    . Parasympathomimetics are a group of drugs that act either by directly stimulating the muscarinic receptor, for example pilocarpine, or by inhibiting the enzyme acetylcholinesterase, which hydrolyses the acetylcholine in the synapse.
  3. ^ "Dorlands Medical Dictionary:parasympathomimetic". Archived from the original on 2009-07-26.
  4. ^ Parasympathomimetics
  5. ISBN 0-7216-7757-6
  6. S2CID 244530010
    .
  7. ^ "Medicinal Chemistry of Adrenergics and Cholinergics". Archived from the original on 2010-11-04. Retrieved 2010-10-23.
  8. PMID 2003276
    .

External links