PSYC 475 Lecture Notes - Lecture 3: Hyoscine Butylbromide, Tachycardia, Physostigmine
Document Summary
Buscopan is an anticholinergic agent; prevents ach from acting acetylcholine decreases the heart rate; it has an inhibitory effect. Iv administration is way faster than pill form and the drug gets distributed rapidly throughout the circulatory system. There are a number of barriers in place that can affect the distribution of drugs cellular membranes capillary walls blood-brain barrier. Cellular membranes phospholipid bilayer passive diffusion: high concentration > low concentration the higher the concentration difference, the faster the drug enters most psychoactive drugs are all very lipid soluble partition coefficient: shows how lipid soluble the drug is. Capillaries (after crossing the cellular membrane, drug enters the capillaries) fenestra: windows in the capillary larger than most drug molecules independent of lipid solubility. Ache breaks down ach and reverts it back to a and ch this is an important mechanism to reduce ach activity on postsynaptic cell physostigmine is lipide soluble but neostigmine is not.