Methods of determining active levels of drugs in fluid samples

Abstract

Methods for determining the presence and level of active drugs in fluid samples are provided. Advantageously, entire families or classes of drugs can be tested for in one test by identifying the enzyme or receptor upon which members of that drug family act and measuring enzyme activity levels or binding activity levels of receptors. Methods for establishing standard activity levels of these drugs based upon results from samples having known quantities of drug therein are also provided.

1 . A method of determining the presence of active beta-blocking drugs in a fluid sample, comprising the steps of:
 providing a first fluid sample, said fluid sample containing a target ligand operable for binding to a specific receptor; and   assaying said sample for the presence of said active beta-blocking drug.   
     
     
         2 . The method of  claim 1 , said assaying step comprising the steps of:
 adding a quantity of labeled ligand to said fluid sample, said labeled ligand operable for binding to said specific receptor; and   contacting said fluid sample containing said target ligand and said labeled ligand with a membrane expressing said specific receptor.   
     
     
         3 . The method of  claim 1 , further comprising the step of determining the concentration of active beta-blocking drugs in said fluid sample. 
     
     
         4 . The method of  claim 3 , further including the step of comparing said determined concentration of active beta-blocking drugs with a known standard of active beta-blocking drug concentration. 
     
     
         5 . The method of  claim 4 , said known standard of active beta-blocking drug concentration being correlated with the concentration of active beta-blocking drugs present in said fluid after a known dosage of beta-blocking drugs is taken by a patient. 
     
     
         6 . The method of  claim 5 , further comprising the step of determining if a patient is taking a prescribed dosage of beta-blocking drugs by comparing said determined concentration with said known dosage. 
     
     
         7 . The method of  claim 1 , said fluid sample comprising urine. 
     
     
         8 . The method of  claim 4 , said known standard being representative of said assay result when no beta-blocking drugs are present. 
     
     
         9 . The method of  claim 3 , said specific receptor being selected from the group consisting of beta-adrenergic receptors. 
     
     
         10 . The method of  claim 9 , said specific receptor being a B1 adrenergic receptor. 
     
     
         11 . The method of  claim 3 , said determined concentration being correlated with a known standard of active beta-blocking drug concentration. 
     
     
         12 . The method of  claim 1 , said beta-blocking drug being selected from the group consisting of atenolol, propranolol, metoprolol, nadolol, pindolol, timolol, cavediol, and sotalol and combinations thereof. 
     
     
         13 . The method of claim  27 , said determining step including the steps of:
 contacting said sample with a receptor specific for beta-blockers and a labeled drug, said drug operable for indicating an interaction between said labeled drug and said determined drug with said receptor.   
     
     
         14 . A method of determining the presence of an active drug in a fluid sample, said drug in its active state capable of binding with a selected receptor and inhibiting binding of a target ligand to said receptor, said method comprising the steps of:
 providing a first fluid sample, said sample including said receptor;   adding a quantity of said target ligand to said first fluid sample;   measuring the binding activity level of said ligand to said receptor; and   determining the presence of said active drug by said measured binding activity level.   
     
     
         15 . The method of  claim 14 , further comprising the step of comparing said measured binding activity level with a standard binding activity level. 
     
     
         16 . The method of  claim 15 , said standard binding activity level representing the binding activity level of said receptor with a known quantity of said target ligand. 
     
     
         17 . The method of  claim 14 , further comprising the step of correlating said measured binding activity level with the concentration of said active drug. 
     
     
         18 . The method of  claim 17 , said correlating step including the step of comparing said measured binding activity level with a standard binding activity level. 
     
     
         19 . The method of  claim 18 , said standard binding activity level representing the binding activity level of said receptor with a known quantity of said target ligand. 
     
     
         20 . The method of  claim 14 , said measured binding activity level decreasing when said active drug is present. 
     
     
         21 . The method of  claim 14 , said measured binding activity level increasing as the level of active drug in said sample decreases. 
     
     
         22 . The method of  claim 14 , said measured binding activity level being inversely proportional to the level of said active drug in said sample. 
     
     
         23 . The method of  claim 14 , said drug being selected from the group consisting of beta-blocking drugs.