Drug interactions pharmacological effects

Following concurrent administration of two drugs, especially when they are metabolized by the same enzyme in the liver or small intestine, the metabolism of one or both drugs can be inhibited, which may lead to elevated plasma concentrations of the dtug(s), and increased pharmacological effects. The types of enzyme inhibition include reversible inhibition, such as competitive or non-competitive inhibition, and irreversible inhibition, such as mechanism-based inhibition. The clinically important examples of drug interactions involving the inhibition of metabolic enzymes are listed in Table 1 [1,4]. 

Before an antiviral agent becomes a drug, advanced toxicity testing, pharmacological combination, and drug-interaction studies are needed. The use of new cell-based assays that can predict mitochondrial toxicity, lactic acidosis, peripheral neuropathy, anemia, hypersensitivity, lipodystrophy, and other potential side effects can alleviate these issues (Stuyver et al. 2002). 

Differentiate antidepressants according to pharmacologic properties, adverse-effect profiles, pharmacokinetic profiles, drug interaction profiles, and dosing features. 

The major drug interactions of antidepressants are shown in Table 35—6.9,19,30 Antidepressants cause both pharmacodynamic (e.g., additive pharmacologic effects) and pharmacokinetic (e.g., changes in drug levels) interactions with other medications. 

The most significant drug-nutrient interactions result in reduced bioavailability and suboptimal pharmacologic effect (Table 58-4). Continuous feeding requires interruption for drug administration and medications... 

Efficacy pharmacology Evaluation of a drug s characteristics, effects, and uses with regard to the target illness, and its interactions with living organisms. 

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