The major ideas in the pharmacology lecture
 
Drugs must get into the blood.  Ability to do this depends on proximity of injection site to blood vessels and lipid solubility.
Drugs must get from blood to target in brain.
  May get stored in fat on the way.
  blood brain barrier
Drugs must be eliminated
  metabolized in liver until water soluble
  excreted by kidney
Drug effects can be quantified by a dose-response curve.

Pharmacology lecture outline
V. Definition and properties.
 A. A drug is a nonfood chemical that enters body and alters a biological process
               (need not be psychoactive). This isn't a perfect definition.
 B.  classification of drugs, there are lots of ways to do this, we will classify drugs by  action on nerve cells.
 C.  Main effects and side effects. (All drugs are dirty drugs).
VI. Classification
 A. sedatives
  1. alcohol
  2. barbiturates
  3. benzodiazepines
 B. misc: marijuana and nicotine
 C. opiates (problem with definition of narcotics)
 D. stimulants
 E. Antidepressants
 F. antipsychotics
VII. Pharmacokinetics: how drugs are distributed in body as function of time.  Drugs must get from administration site to blood and from blood to brain.
 A. lipid solubility is most important factor in absorption.  Don’t worry about the discussion of drug ionization from the bottom of p 14 through the first column of pg. 16.  You don’t need to understandd Fig. 1-6.
  1. Most drugs have some water solubility and some fat solubility, but one is usually greater than the other.
 B. IV: effects are rapid.
  1. may be necessary if patient cannot take drug in another form
  2. permits accurate control of dose.
  3. problem: needles must be sterile
  4. rapid action makes it difficult to counteract overdose.
 C. Inhalation: also very fast, especially for fat soluble drugs.
  1. anesthesia
  2. Nicotine and THC are in particles; dissolve when hit wet
                         membranes of lungs and are absorbed into blood.  particles
                         cannot be excreted by lungs; so these drugs may injure
                         epithelium.
 D. Mucous membranes: cocaine, chewing tobacco
 E. Skin patches: constant levels
 F. Oral: most complex
  1. absorb from stomach or intestine. Must be absorbed across
                         wall of stomach or intestine into the blood. Crossing of cell
                         membranes depends on fat solubility.
  2. Basic drugs are not fat soluble in stomach, so are poorly absorbed orally.
  3. Some drugs, e.g., insulin will be destroyed by enzymes in
                         digestive system so can't be used orally.
VIII. Drug has to get into the blood, then has to get out of the blood and into the brain.
 A. Only the amount in the blood is available to the brain.
 B. brain has to compete with  fats.
 C. When first take a drug, some is stored in fat as blood goes through fat tissue.
 D. Drug stored in fat is not immediately available to brain
 E. As drug is metabolized by liver, blood is depleted and more moves from fat to blood. So drugs that are extremely fat soluble have very slow time course of action-marijuana.
 F. Blood brain barrier
  1. capillaries
  2. astrocytes
IX. Excretion
 A. Drugs are metabolized by liver until they are water soluble
  1. liver enzymes can be induced
  2. metabolites can be long lasting: accounts for the ability to detect mj for 30 days after   use.
  3. half-life
  4. Don’t memorize fig 1-9. You need to know the names of the enzymes involved in metabolism of common drugs, but you do not need to know the structures of molecules.
 B. Then are eliminated by kidneys.  You need to understand the function of the kidneys in drug excretion, but you don’t ned to memorize the names of all the parts.
 C. understanding of excretion is important in treating overdose.  Can manipulate the chemistry of urine to excrete drugs faster.  This concept is used to treat barbiturate overdose.
X. Descriptions of drug action:
 A. dose-response curve, potency, effectiveness, safety (therapeutic index) LD50/ED50
 B. You should understand the point of Figs. 1-10, 1-11, and 1-12 but you don’t need to memorize each curve.