Direct parasympathomimetics

Parasympathomimetics are drugs that mimic the effects of the parasympathetic nervous system. Direct parasympathomimetics are substances that act directly on M receptors. They mimic the properties of acetylcholine.

Effects and uses[edit | edit source]

They increase the tone and motility of the GIT and smooth muscles. The main indication for the use of direct PSMs is GIT and bladder atony after general anesthesia.

Adverse effects[edit | edit source]

Diarrhea;
perspiration;
miosis ;
nausea ;
increased salivation;
bradycardia ;
reduced cardiac output.

Contraindications[edit | edit source]

Urinary tract obstruction;
megacolon

Substances Used[edit | edit source]

Acetylcholine[edit | edit source]

It is not absorbed from the GIT. Administration iv – for rapid breakdown by acetylcholinesterase ( ACHE ) only works for a short time .

Betanechol[edit | edit source]

Degraded by glutyrylcholinesterase - slowly metabolized. Use for bladder detrusor stimulation.

Carbachol[edit | edit source]

Degraded by glutyrylcholinesterase - slowly metabolized. It does not cross the BBB ( blood-brain barrier ). Used as a miotic in glaucoma .

Pilocarpine[edit | edit source]

An alkaloid of vegetable origin. It has a tertiary N atom, is characterized by increased lipophilicity and good penetration into the CNS and cornea. It is an agonist of muscarinic receptors. It is mainly used in ophthalmology, where it induces miosis , it is used in glaucoma and xerostomia .

Links[edit | edit source]

References[edit | edit source]

ABZ.cz. ABZ dictionary of foreign words: Concept of parasympathomimetics [online]. [feeling. 2010-11]. < https://slovnik-cizich-slov.abz.cz/web.php/slovo/parasympatomimetika >.

HYNIA, Sixtus. Pharmacology in a nutshell. 2nd edition. Prague: Triton, 2001. ISBN 80-7254-181-1 .