Anti-Cholinergics (aka Anti-Muscarinics)

• Remember, these block acetylcholine receptors and should therefore yield sympathetic effects

• Effects include blind as a bat (mydriasis), red as a beet (flush), dry as a bone (xerostomia), mad as a hatter (psychosis), and hot as a hare (increased body temperature).

• All competitively block muscarinic receptors (quarternaries block nicotinics as well)

• Cross BBB

• Do not block nicotinic receptors

  1. Atropine – (natural) behavioral effects, biphasic cardiac response (low dose = bradycardia, high = tachycardia), relax smooth muscle, decrease secretions, etc.

  2. Scopolamine – (natural) motion sickness, vestibulation, biphasic cardiac response, relax smooth muscle, decrease secretions, etc.

  3. Homatropine, Cyclopentolate, Tropicamide – [eyes] used to examine mydriasis and measure cycloplegia

  4. Pirenzepine, Telenzepine – [GI] primarily block M1 to decrease gastric secretion in peptic ulcer

  5. Dicyclomine – [GI] use for visceral hypermotility and spasms

  6. Oxybutynin, Oxyphencyclimine – used to relieve bladder spasms following urologic surgery

  7. Benztropine, Trihexyphenidyl – [CNS] use to treat Parkinson’s

• Do not cross BBB

• Able to block nicotinic receptors

  1. Propantheline, Methantheline, Mepenzolate, Methscopolamine – use for visceral hypermotility and spasms, as well as duodenal ulcer treatment

  2. Glycopyrrolate – use for visceral hypermotility and spasms, duodenal ulcer treatment, and cardiovascular disorders; pre-anesthetic drug of choice to reduce salivation (due to mild effect on heart in comparison to atropine)

  3. Ipratropium – key respiratory drug, use to treat bronchial asthma and COPD

Category: Pharmacology Notes