ch.3: psychopharmacology Flashcards
Explain the difference between psychopharmacology, pharmacodynamics, and pharmacokinetics.
Pharmacology is the study of psychoactive drugs and how they affect the brain and behavior, while pharmacodynamics is the effect that drugs have on the body. Drugs either enhance the effects of a neurotransmitter(agonists) or dampen or block the effects of a neurotransmitter (antagonists). Pharmacokinetics deals with how drugs are handled by the body: movement and elimination.
What are the different routes of administration (ways to take drugs)?
Oral: the most common form; via small intestine. Relatively safe, but slow.
Rectal: suppositories; can be used if person is vomiting or unconscious; unpredictable rate, as it’s near the bigger organs.
Sublingual: under the tongue.
Buccal: lining of the mouth.
Nasal: inhaled or snorted.
Inhalation: into a vein(very fast and allows dose accuracy, but can cause clots or infection), muscles, or under the skin(slowest form, can only do small volumes).
Transdermal: patches on skin.
What is bioavailability?
The extent to which a drug is able to reach its site of action.
Describe the metabolism of drugs.
Drug metabolism is equal to biotransformation. It deals with how we eliminate drugs from our body. It’s mostly done by the liver, which allows fat soluble molecules to become water soluble. For ex, whenever someone drinks alcohol, you can sometimes smell it from their sweat. The main way the body gets rid of drugs is urine.
What is the half-life of a drug?
It’s the amount of time in which the drug’s amount is consumed in half by the body.
What is efficacy? Then compare it with potency.
The extent to which a drug activates a receptor More = more severe side effects. Antagonists don’t have any because they don’t elicit a physiological reaction. Ex: if you take either morphine or aspirin, your pain would go away. This is efficacy. However, 1/2 of morphine OR 2 aspirins is needed for your pain. This is potency.
Describe the difference between tolerance and sensitization.
Tolerance means that a higher dose is required to achieve the same effects over time, while sensitization means the same dose of a drug elicits a greater response over time.
What is the first pass effect?
It’s the reduction in the amount of a drug reaching sites of action due to metabolism of orally administered drugs by enzymes in the stomach and liver.
Describe absorption, distribution, metabolism, and elimination of drugs.
Absorption: Unless given IV, a drug must cross cell membranes before it can be transported in blood plasma. The diffusion of drugs across membranes is affected by various factors.
Distribution: In blood plasma, a drug will reach all parts of the body. Some side effects would be due to binding at receptors outside the brain. Some drugs would be temporarily inactivated by fat storage or attached to blood plasma proteins. The blood-brain barrier acts as a selective barrier to drug distribution.
Metabolism: equals biotransformation. Allows us to eliminate drugs from the body and can result in the production of a new compound that’s either inactive or active (or even more active than the parent compound). The main site is the liver.
Elimination: Main way is urine. Metabolic enzymes in the liver allow fat-soluble molecules to be water-soluble. Ex: When someone drinks alcohol, you can sometimes smell the alcohol from their sweat.
Describe agonists.
“The highs”, DIRECT agonists mimic the effects of a particular neurotransmitter by binding to postsynaptic receptors (in the pre-synaptic neuron) in a similar way and produces a similar response in the post-synaptic neuron. More action potentials will occur, which means more firing. INDIRECT agonists enhance the action of a natural neurotransmitter.
Describe antagonists.
“the depressants”, these bind to a receptor but has no physiological effect on it. They compete with the neurotransmitter for binding at the same receptor site. Basically, it blocks the effect of the neurotransmitter by reducing the number of receptors available for it to activate. No action potentials means no firing.
Review the graphs for half-life, potency, efficacy, and therapeutic index.
Nothing.
