principles of psychopharmacology

what is a drug?

• exogenously administered

• without nutritional value

• not produced by the body

what is a psychoactive drug?

• exogenously administered

• without nutritional value

• not produced by the body

  • AND

• causes changes in mood and/or behavior

• AKA psychotropic

what is psychopharmacology?

• the study of the effect of drugs on behavior

neuropsychopharmacology

effects of drugs on neurons

psychotropic/psychoactive

changes in mood and behavior

what is psychopharmacology responsible for?

• understanding drugs

• psychotherapeutic medications for neurological disorders and diseases

• autonomic nervous system

• addiction

site of action

where a drug interacts with our cells

drug effects

• observable changes

  • physiology

  • behavior

  • mood

“effects”

• drug action vs drug effects

• therapeutic effect vs side effect

• specific effect vs nonspecific effect

drug action vs drug effect

• changes produced at the target site (da)

• observable change (de)

therapeutic effect vs side effect

• desired physical/behavioral effect (te)

• everything else (se)

specific effect vs nonspecific effect

• directly due to the chemical interaction (se)

• subjective changes (nse)

placebo effect

• an example of a nonspecific effect

  • has both therapeutic and side effects

what is a nocebo effect?

• makes you feel worse

pharmacodynamics vs pharmacokinetics

• what the drug does to your body vs what the body does to the drug

what is absorption?

• how the drug gets into the blood stream

what is vocab related to pharmacokinetics?

• bioavailability

• routes of administration

• absorption/distribution

• binding

• inactivation

what is bioavailability?

• the amount of drug in the blood stream

routes of administration

• Oral

• Rectal

• Intravenous

• Intramuscular

• Intraperitoneal

• Subcutaneous

• Inhalation

• Topical/Transdermal

• Intranasal

• Epidural

• Intracerebroventricular

• Gene Therapy (Viral Vectors)

adv and disadv of dif routes of admin

how are lipid bilayers formed?

• fat and water do not like eachother

• water loving (hydrophilic) heads like water content of intra and extra cellular fluid, but the hydrophobic tails do not. the tails turn toward eachother and do not contact outside fluid

what must happen to the chemical in order to move via diffusion?

• intra and extra fluid is charged - so in order to move via diffusion, the chemical must be non-ionized (uncharged)

what is lipid solubility?

• easily crosses the membrane

  • i.e. steroid hormones

  • heroin more lipid soluble than morphine

what affects lipid-solubility?

• ionization

what is ionization?

• the process of losing or gaining an electrons

what does lack of electrical change do?

• increases lipid-solubility

what does it mean that women have more fat than water?

• women have a higher drug concentration at the target site

what does passive diffusion across lipophilic membranes depend on?

• degree of ionization

what do the ionized form of a drug carry?

• a charge and is polar so it cannot pass through membranes

what is active transport limited to?

• drugs that are similar to endogenous substances

explain the figure

FIGURE 1.6  Effect of ionization on drug absorption 

On the right side of the cell barrier in stomach acid (pH 2.0), aspirin molecules tend to remain in the non-ionized form (1), which promotes the passage of the drug through the cell walls (2) to the blood. Once the intact aspirin molecules reach the blood (pH 7.4), they ionize (3) and are “trapped” in the blood to be circulated throughout the body. In the lower portion of the figure, when the aspirin has reached the intestine, it tends to dissociate to a greater extent (4) in the more basic pH. Its more ionized form reduces passage (5) through the cells to the blood, so absorption from the intestine is slower than from the stomach.

how long does it take drug to circulate

• circulated completely within 2 minutes

what do more vascularized areas mean?

• higher drug concentration

BBB - what gets in and how is it dif from blood

• contents of CSF are stable unlike blood

• only gets in if small and lipid-soluble