Drug Psychopharmacology Flashcards
What are psychoactive drugs?
psychoactive drugs are drugs that influence subjective experience and behavior by acting on the nervous system
What is the difference between pharmacokinetics and pharamcodynamics?
Pharmacokinetics: the effect of the body on drugs
the study of the time course of drugs and their metabolites on the body (summarized as ADME)
Pharmacodynamics: the effect of the drug on the body
the study of the time course and intensity of pharmacological treatments (the effect a drug has on neurons)
What are the four routes of drug administration?
Ingestion, Injection, Inhalation, Absorption
What is ingestion and what are the advantages and disadvantages?
Once swallowed, drugs dissolve in the fluids of the stomach and are carried to the intestine, where they are absorbed into the bloodstream
Advantages:
- convenient
Disadvantages:
- timing and magnitude of the drug effects are greatly influenced by food in the stomach
- may be broken down to inactive metabolites before being absorbed
What is injection (4 types) and what are the advantages and disadvantages?
Subcutaneous injection: injection into the fatty tissue just beneath the skin
Intramuscular injection: injection into large muscles
Intravenous injection: injection directly into veins
IV injection: many drug addicted people prefer the IV route because the bloodstream delivers the drug directly to the brain
advantages
- the effects are strong, fast, and predictable
disadvantages
- risk of death from overdose, impure drugs, allergic reactions (little opportunity to counteract)
What is Inhalation and what are the advantages and disadvantages?
some drugs can be absorbed into the bloodstream through the rich network of capillaries in the lungs
disadvantages
- hard to precisely regulate the dose of inhaled drugs
- risk of lung damage
What is absorption and what are the advantages and disadvantages?
some drugs are readily absorbed through the mucous membranes of the nose, mouth, or rectum (cocaine = example)
disadvantages
- these membranes can be easily damaged
What is the ADME process?
Absorption, Distribution, Metabolism, Excretion
Absorption: when a drug is released form its admin site and enters the bloodstream
- blood brain barrier blocks many potentially dangerous neurotoxins from penetrating the neurons of the CNS
Distribution: the movement of a drug one in the bloodstream
- route = first past metabolism usually occurs in the liver, drugs reach places like the heart and the brain first, drugs are then distributed to the rest of the body (skin, muscle, etc)
Metabolism: the body using the drug (mostly metabolized by the liver enzymes) and giving off a byproduct
Excretion: getting rid of the byproduct
How do we measure tolerance?
decrease in response elicited by the same dose of drug
OR
increase in dose of drug to produce the same response
What are the two types of tolerance effects
- metabolic tolerance: a decrease in the amount of the drug reaching the target cells
- Functional tolerance: a decrease in the ability of the drug to influence the target cells
How is tolerance different from sensitization?
Drug tolerance is a right shift in the dose-response curve
sensitization is the opposite, it is a left shift in the dose-response curve
What is the Psychopharmacological view on drug tolerance (role of learning)?
for contingent tolerance, the exposure to a drug is not enough to gain tolerance, experience of the effect is necessary
for conditioned tolerance, there is a major role of environment/context during drug exposure
What is contingent drug tolerance?
refers to demonstrations that tolerance develops only to drug effects that are actually experienced
- usually demonstrated before and after experiments
- tolerance is substantially greater in the drug before test condition than in the drug after test condition
What is conditioned drug tolerance?
refers to demonstrations that tolerance effects are maximally expressed only when a drug is administered in the same situation in which it has previously been administered
- drug users may be particularly susceptible to the lethal effects of a drug overdose when the drug is administered in a new context
- Context (CS) + Drug (US) = conditioned compensatory responses
