The following schematic represents the activity:

  
    
      
        A
        
          
            →
            
               
               
              p
               
               
            
          
        
        B
      
    
    {\displaystyle A{\xrightarrow {\ \ p\ \ }}B}
  
where p is the activation rate coefficient. It is customary that p is called a rate constant, but, since the p stands for measure of the intensity of the stimulus causing the activation, p may be variable (non-constant).
The mechanism may specifically include receptor internalisation and resistance to endogenous vasoconstrictors causing worsening in symptoms post use of medication. Oxymetazoline-induced tachyphylaxis and rebound congestion are reversed by intranasal fluticasone. See also
References
External links
Tachyphylaxis and Tolerance: Biomathematics of Rate Sensitivity
Tachyphylaxis at the US National Library of Medicine Medical Subject Headings (MeSH)