Psychopharm Terms for Test 1

To place a drug at its site of action in an effective concentration, maintained for an appropriate amount of time to cause a desired effect

The effects of the body on a drug
-Administration
-Absorbtion
-Distribution
-Biotransformation & metabolism
-Elimination

-The effects of the drug on the body
-binding
-function (effecting heart rate, blood pressure, depression, etc)

concentration of a drug in the blood that is free to interact w/ target sites

-The tails of the phosopholipids are fatty acid tales that are not charged and do not like water
-Water molecules are polar, they are attracted to each other
-the phospholipid portion of the phosophoplipid molecule (the polar head) likes water

-fussion through dissolving in the membrane and travelling across
-facilitated diffusion through protien molecules embedded in the membrane
-Active transport takes energy
-Passive diffusion= down the concentration gradient

-Drugs given orally must pass through
-a sealed tube from the mouth to the rectum, sealed in epithelial cells
-Drugs need to pass through the GI tract to get to capillary cells
-drug need to be water soluble
-Drug must be gastric resistent, low pH, must get past enzymes and be lipid soluble

-concentration of the drug (the more you take, the faster it goes)
-whether the drug is a weak acid or a weak base
-pH of absorbing surface
-PKA
-Area of absorbing surface

the concentration of H+ is high at...

the concebntration of H+ is low at...

-represents the pH at which 50% of a drug is ionized
-is unique for each drug molecule

"Iion Trapping" is the ionization that occurs when an acid enters capillaries lining the GI tract, preventing reabsorbtion into the GI lumen

- Larger surface area
- Molecule will spend more time in small intestine than stomach- Longer transit time
-Less mucous in the small intestine
-Higher pH for weak bases in SI

a. Cigar smoke is more basic
b. Cigarette smoke is acidic and doesn’t get absorbed well by the mouth

o Junctions are a little bigger to allow movement of substances into brain
o Area Postrema- chemical trigger zone/vomiting center
• A noxious substance entering the bloodstream can activate vomiting by acting at this site in the medulla
o Median Eminence
• Hypothalamitic area that regulates anterior pituitary secretion through release of neuropeptides
o Subfornical Organ at Third Ventricle
•Circumventricular structure important for fluid regulation

* Area of weak blood-brain barrier
*chemical trigger zone/vomiting center
• A noxious substance entering the bloodstream can activate vomiting by acting at this site in the medulla

* Area of weak blood-bran barrier • * Hypothalamitic area that regulates anterior pituitary secretion through release of neuropeptides

* area of weak blood-bran barrier
* Circumventricular structure important for fluid regulation

Urine, Bile, Feces, Saliva, Sweat, Breast Milk, Expired Air, Hair

o GI Tract → Liver → Bile Duct → GI Tract → Elimination
→ Reabsorption

pores only large enough for water to get through

promotes reabsorption of water (antidiaretic hormone)

-Hormonal Regulator
-Made in adrenal cortex
•Increases sodium reabsorption

-Diuretic
-Increases glomerular flow- more caffeine- more urine, increases excretion
-

-Diuretic
-inhibits ADH release

-Uniodized or lipid soluble molecules are reabsorbed
-At higher ph, acids are more ionized and excreted at faster rates
-At lower ph, bases are more ionized and excreted at faster rates
-pH of kidney tubules ranges from 4-8 and varies over time

o Stomach
o Intestine
o Blood
o Kidney
o Brain
o Liver

-the time for the plasma drug concentration to decline by 50%
-90% of the drug is lost in 3.32 half-lifes
-eah person has a personalized half-life for each drug concentration affected by weight, health & gender

reduced on the very young and the very old

Genetic/hormonal diferences

-dose necessary to give a desired affect
-Accessibility, Affinity & Intrinsic activity

How fast/well does a drug get to its receptor?
-pharmacokinetics

affective dose of a drug

-Based on ED50/TD50 or ED99/TD1
-can change over time w/ drug tolerance, curves become closer and the ratio becomes smaller
-Ti can vary from person to person (someone metabolizes differently, age factors, taking other drugs)

Safer drug

Protiens!
-receptors, enzymes, transporters, ion channels

-sit in the membrane
-sequence of amino acids that cross the membrane

-Proteins for drugs that are not lipid soluble and so are placed on the surface of the cell
-More common

-drugs interact with receptors inside of cell
-lipid soluble steroid hormones pass through the cell

-presence of protein in a cell

-presence of protein in a tissue sample w/ several ground up cells

-disassociation constant
-low Kd equals high affinity
-determined empirically (k2/k1)
-measure of drug affinity for a specific receptor

A drug has a high affinity for that receptor

-transient and reversible
-k1 is the rate at which drug associates with receptor
-

-concentration of radioligand that labels 50% of total receptors in sample

1 proton, 1 neutron
-unstable compound
-isotope of hydrogen used to measure receptor binding

1 proton, 2 neutrons
-isotope of hydrogen used to measure receptor binding
-used in lab

The surplus of neutrons makes it want to decay into a more stable condition
-gives off energy as it does this called beta particle emission
-beta particle emission is detectable (has same particle as electrons)

-Take radioactive form of drug that you think has high affinity and measure beta particle emission

replace hydrogen with tritium

During the process of a competition experiment, medium in which reaction will occur when you add drug

During the process of a competetion experiment
-Place filters in scintilation tube
-count bound [3H] ligand on filters using scintilation
-so during that 5 minutes how many decays have occured?

replace hydrogen with tritium

During the process of a competition experiment, medium in which reaction will occur when you add drug

During the process of a competetion experiment
-Place filters in scintilation tube
-count bound [3H] ligand on filters using scintilation
-so during that 5 minutes how many decays have occured?

stomach
-theoretically raising the Ph of the stomach could allow a base to be absorbed

goes to the brain!

most common binder in the blood
-plasma binding protein that binds primarily to acids (and some neutrals)

-binder in the blood has a higher affinity for basic drugs

basic unit of the kidneys
1.5 million in each kidney
network of tubules blood plasma and proteins don't go in

-Larger molecules end up in the bile tract
-more lipophillic molecules too

fluctuate betweens between 4-8 throughout the day due to any # of variables

The process by which natural metabolism (enzymes) o the body changes the property of the drug (for ex. from acid to base)

the lower the affinity of the competitior drug for the receptor

1) Must be synthesized or present in cell

2) Release must produce effect in target cell

3) Effect must be the same if artificially placed on cell

4) Mechanism for removal (except for nitric oxcide)

Sympathetic nervous system

Parasympathetic nervous system

-Parasympathetic nervous system releases
-slows heart beat