Interactions, drug additive

Select an agent to minimize adverse drug reactions and interactions when additional drug therapy is needed. Does the patient have prescription coverage or is the recommended agent in the formulary ... 

Vigilance for drug-drug interactions is required because of the greater number of medications prescribed to elderly patients and enhanced sensitivity to adverse effects. Pharmacokinetic interactions include metabolic enzyme induction or inhibition and protein binding displacement interactions (e.g., divalproex and warfarin). Pharmacodynamic interactions include additive sedation and cognitive toxicity, which increases risk of falls and other impairments. 

It was recognized very early that diffuse reflectance spectroscopy could be used to study the interactions of various compounds in a formulation, and the technique has been particularly useful in the characterization of solid state reactions [24]. Lach concluded that diffuse reflectance spectroscopy could also be used to verify the potency of a drug in its formulation. In addition, studies conducted under stress conditions would be useful in the study of drug-excipient interactions, drug degradation pathways, and alterations in bioavailability owing to chemisorption of the drug onto other components in the formulation [24]. 

Research on drug interactions with zolpidem and zaleplon is limited, but any drug with CNS depressant effects could potentially enhance the CNS depressant effects of zolpidem and zaleplon through pharmacodynamic interactions. In addition, zolpidem is primarily metabolized by CYP 3A3/4, and zaleplon is partially metabolized by CYP 3A3/4. Thus, inhibitors of these enzymes may increase blood levels and the toxicity of zolpidem. 

Proteins and other macromolecules are mainly cleared by high-capacity elimination processes such as renal hltration and liver metabolism. A coadministered drug can affect these processes and lead to serious drug-drug interactions. In addition, drugs that influence receptor-mediated clearance of the therapeutic protein may also result in important drug-drug interactions. 

Drug interactions In a randomized, double-blind study, Zenapax or placebo was added to an immunosuppressive regimen of cyclosporine, mycophenolate mofetil, and steroids to assess tolerability, pharmacokinetics, and drug interactions. The addition of Zenapax did not result in an increased incidence of adverse events or a change in the types of adverse events reported. The following medications have been administered in clinical trials with Zenapax with no incremental increase in adverse reactions cyclosporine, mycophenolate mofetil, ganciclovir, acyclovir, azathioprine, and corticosteroids. 

Most literature reports of pharmacodynamic botanical-drug interaction involve the anticoagulant warfarin, likely because it has therapeutic end points such as the INR and PT, which are routinely closely monitored. In addition, most botanicals possess anticoagulant and/or antiplatelet activities, and their combined use with warfarin provides a good example of pharmacodynamic interaction with additive pharmacological effect. 

The opposite, the reversal of drug-membrane interaction by addition of Ca2+ ions, has been also studied by NMR spectroscopy using the example of multi drug resistance modifiers [14]. 

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