Medications pharmacodynamic change

Pharmacodynamic changes in the elderly are also documented however, they are not as well-researched or defined as are pharmacokinetic changes. Pharmacodynamics refers to the change in response to the medication. Possible mechanisms include ... 

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. 

Pharmacokinetic changes are clinically important only if they engender pharmacodynamic ones. A dramatic example of this linkage is exemplified by the CSS. Previously thought to be uncommon, more than 125 cases of CSS have been reported (Mills, 1997 Mason et ah, 2000, Radomski et ah, 2000). Because of the common usage of SSRIs and co-medications, which include St. John s wort, some pro-serotonergic opioids, and ec-... 

The elderly are more likely to be sensitive to a number of different classes of medication because of changes in pharmacodynamics. It is very important to... 

It is debatable if age alone is an independent risk factor for ADR however, the elderly are more susceptible to ADRs because of physiological changes resulting in altered pharmacokinetics or pharmacodynamics. Some studies have shown that when controlling for confounders such as clinical status of the patient, number of medications, and length of hospital stay, age alone does not predict ADRs. ... 

Hormonal fluctuations during the menstmal cycle, postpartum period, and peri- and postmenopause phases may cause differences in the pharmacokinetics and pharmacodynamics of drugs (e.g., changes in drug absorption, distribution, metabolism, and excretion). Thus clinicians must be aware of gender differences when prescribing medications. " ... 

The technological challenges for pharmacoproteomics are exceptional (see Table 13.1-3). Protein microarrays are an emerging class of nanotechnology for tracking many different proteins simultaneously. However, translation into the medical practice is very slow. On the other hand, proteomic changes in cultured cell lines might not fully reflect pharmacodynamic interactions because of the lack of the tissue microenvironment [11]. 

Azithromycin. A study in 64 healthy medical students found that azithromycin 750 mg had no effect on the metabolism of a 10- or 15-mg dose of midazolam, and did not alter the performance of a number of psychomotor tests. A study in 10 healthy subjects given azithromycin 250 mg daily found that some small changes in pharmacokinetics of midazolam 15 mg (a possible small delay in its onset of action), but its pharmacodynamic effects were unaltered. Other studies confirm that azithromycin does not interact with midazolam. ... 

Drug-drug interactions Fluconazole and voriconazole The kinetic and dynamic interactions of diazepam 5 mg with variable doses of fluconazole and voriconazole have been evaluated in a randomized controlled study in 12 healthy volunteers [1(T]. Both voriconazole and fluconazole markedly increased exposure to diazepam. After voriconazole, the plasma diazepam concentration increased 2.2-fold and the mean half-life was prolonged from 31 to 61 hours. After fluconazole, the plasma diazepam concentration increased 2.5-fold, and the mean half-life was prolonged from 31 to 73 hours. The peak plasma diazepam concentration was unchanged by voriconazole and fluconazole. The pharmacodynamics of diazepam showed only minor changes. Caution should be taken during concurrent administration of diazepam with these medications. 

In 1938, a group of Laboratory of Pharmacodynamics and Medical Materil, France suggested that potassium in the extracts of Ruscus aculeatus might show their diuretic effect by the improved change of blood circulation... 

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