Today our topic of discussion is Basic Pharmacologic Principles.
Basic Pharmacologic Principles
Basic Pharmacologic Principles
- Pharmacokinetics: It refers to the movement of medication molecules in the body, including absorption, distribution, metabolism and excretion of medications
- Absorption: The movement of a medication from its site of administration (e.g. GI tract, muscle, skin or subcutaneous tissue) tissue to the bloodstream.
- Distribution: The transportation of a medication to its site of action by bodily fluids
- Metabolism: Occurs primarily in the liver. Individuals diagnosed with liver dysfunction have a decreased ability to metabolize medications and are at risk of undue accumulation of medication and possible toxicity
- Excretion: The elimination of a medication from the body primarily through the kidneys. Individuals diagnosed with renal dysfunction should be monitored for an increase in duration and intensity of medication responses.
- Medication responses: Plasma medication levels can be regulated to control medication responses, Medication dosing attempts to maintain plasma levels between the minimum effective concentration (MEC) and the toxic concentration. When a medication has achieved plasma levels that are effective and not toxic, the plasma level is within the therapeutic range..
- Therapeutic index (TI): Medications with a high I have a wide safety margin. Therefore, there is no need for routine serum medication level monitoring. Medications with a low TI should have serum medication level monitored closely. Monitor peak levels based on the route of administration. For example, an oral medication may have a peak of 1 to 3 hours after administration. Whereas if the medication is given intravenously, the peak time might occur within 10 minutes.
- Half-life: The plasma half-life is the time taken for the plasma concentration of the drug to decline to one-half of its value.
- Pharmacodynamics (Mechanism of action): Describes the interactions between medications and target cell, body systems, and organs to produce effects. Medications interact with cells in one or two ways. Medications can mimic the receptor activity regulated by endogenous compounds or block normal receptor activity regulated by endogenous compounds. For example, Morphine is classified as an agonist because it activates the receptors that produce analgesia, sedation, constipation, and other effects.
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