Atropine and glycopyrrolate are both alkaloid non-selective antagonists of the muscarinic receptor (M1-M5).
A - Atropine 90% OBA, glyco poorly absorbed \(\to\) IV only
D - Atropine poorly water soluble, glyco poorly lipid soluble. Similar Vd ~2L/kg, both ~50% protein bound. Glyco cannot cross the BBB.
M - Atropine 50% hepatically metabolized \(\to\) inactive. Glyco not metabolized. Remainder excreted in urine.
E - Half-life of both is 2-4 hours, but atropine has a peripheral duration of only ~30 minutes due to redistribution to fat and CNS.
Mechanism: Both drugs block muscarinic receptors, decreasing intracellular cAMP.
Effects of both
CNS effects of atropine