Comprehensive Nursing Pharmacology Q 293

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The extent to which drug is absorbed and transported to target tissue is known as:

  

     A. Steady-state accumulation

     B. Therapeutic drug levels

     C. Bioavailability

     D. Distribution

    

    

Correct Answer: C. Bioavailability

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Bioavailability is the extent to which a drug is absorbed and transported to target tissue. Bioavailability refers to the extent a substance or drug becomes completely available to its intended biological destination(s). More accurately, bioavailability is a measure of the rate and fraction of the initial dose of a drug that successfully reaches either; the site of action or the bodily fluid domain from which the drug’s intended targets have unimpeded access.

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Option A: Steady-state accumulation means that the amount of drug present is sufficient to exert its therapeutic effect. Within pharmacokinetics, the steady-state is a concept of fundamental importance in pharmacology. It describes a dynamic equilibrium in which drug concentrations consistently stay within therapeutic limits for long, potentially indefinite, periods. The concentration around which the drug concentration consistently stays is known as the steady-state concentration.

Option B: Therapeutic drug levels are serum blood tests used to measure the amount of circulating drug present. The therapeutic level of a drug in the bloodstream is the range within which that drug is expected to be effective. The doctor can request a test to measure the amount of a specific drug in the serum portion of the blood.

Option D: Distribution is the process by which drugs are transported to tissues. Drug distribution refers to the movement of a drug to and from the blood and various tissues of the body (for example, fat, muscle, and brain tissue) and the relative proportions of drugs in the tissues.

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