Use of Multiple Medications

Conversely, many patients have psychiatric conditions that require the concomitant use of several psychotropic agents. The carefully considered, rational use of several psychiatric medications must be distinguished from ill-considered polypharmacy. An example of useful combined treatment is the addition of lithium to antidepressant therapy in the case of a patient who has achieved only a partial response to treatment with an antidepressant alone. 

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Age-related changes in phase I metabolism coupled with the use of multiple medications place older patients at increased risk for adverse drug reactions. Adverse drug reactions occur due to either inhibition or induction of CYP enzymes, especially CYP3A, which is believed to be involved in the metabolism of more than one half of the currently prescribed drugs.Clinical outcomes are determined by... 

Concurrent use of multiple medications is another major ADR risk factor. The potential for clinically significant drug interactions and additive adverse effects increases as the number of medications in a regimen increases (28, 29). In a study of over 9000 hospital admissions, the strongest predictor of ADRs was the... 

Concurrent use of multiple medications Multiple comorbid conditions Drug dose and duration of exposure Extremes of age (neonates, children, and elderly)... 

Poor compliance with instructions Use of multiple medications Recreational use of alcohol and illicit drugs Effects of changing hormone levels on drugs... 

When translated, polypharmacy simply means multiple medications. However, the clinical interpretation of this term usually refers to the use of multiple medications in an inappropriate, illogical, or harmful manner to the patient. 

Elderly patients may also be at a higher risk for adverse reactions because of their generally decreased organ fimctions and frequent use of multiple medications. The warnings and precautions of Crestor states that the risks for skeletal muscle effects increase with the use of 40 mg dose, advanced age ( ), hypothyroidism, renal impairment, and combination use with cyclosporine. 

Although most CF patients have shorter half-lives and larger volumes of distribution than non-CF patients, some patients exhibit decreased clearance. Possible causes include concomitant use of nephrotoxic medications, presence of diabetic nephropathy, history of transplantation (with immunosuppressant use and/or procedural hypoxic injury), and age-related decline in renal function in older adult patients. Additionally, CF patients are repeatedly exposed to multiple courses of IV aminoglycosides, which can result in decreased renal function. Evaluation of previous pharmacokinetic parameters and trends, along with incorporation of new health information, is key to providing appropriate dosage recommendations. 

As many as 10% of children have a medication-responsive psychiatric disorder (Riddle et ah, 1998) and there has been a dramatic increase in the use of psychotropic medication to treat mental disorders in youth (Rappley et ah, 1999). Multiple factors account for this increase, including scientific advances in fields such as epidemiology, nosology, neuroscience, drug development, and clinical measurements, and efforts to educate the public about the benefits of early, effective treatment. Despite large gaps between research and practice, many medications are used in children on the basis of a small amount of scientific data. Factors that contribute to this situation are societal desires for rapid, effective treatment, acceptance of medication as a therapeutic modality, and a reimbursement climate in which there is increased pressure for brief treatment. Clearly there is a need to balance clinical and administrative pressures with a resort to treatment based on the best available data. 

It should be noted that polypharmacy per se is not necessarily an inappropriate practice. Most medical disorders, from asthma to AIDS to allergies, are managed with medication combinations. However, it is important to note that the use of multiple concurrent medications appears to rising substantially, suggesting that there is a great need for research data and well-designed studies to inform this practice. In some instances, it may be that the combination, while popular, may be more likely to result in side effects and not particular advantages in treatment efficacy and clinical outcomes (Connor et ak, 2000). 

Adverse drugs reactions are not rare and have increased in number, which may be due to irrational use of multiple drug therapy, availability of most of the drugs as OTC (over the counter) i.e. without prescription and self medication by the patients. 

The threshold dosage of phenylephrine in the average adult has been estimated to be 0.4 mg intravenously, 2 mg subcutaneously, and 50 mg orally. The upper limit for safe dosage in normal adults is approximately 1.5 mg intravenously and 300 mg subcutaneously. Because a 50-ml drop of 10% phenylephrine contains 5 mg of drug, multiple applications can result in overdosage, especially if absorption from the site of administration is enhanced or if the patient is compromised by age, body size, use of concomitant medications, or trauma. Furthermore, the extent of the absorption into the systemic circulation of topically applied phenylephrine is unknown because absorption has been shown to be possibly diminished due to local vasoconstriction. 

The elderly are particularly susceptible to interactions because of the changes in physiology, multiple physician prescribing, increased use of OTC medications, non-adherence to complex regimens, and multiple disease states that complicate the handling of medications. 

As with erythromycin, drug interactions are extremely important with clarithromycin. Because clarithromycin inhibits the hepatic cytochrome P-450 system, it may result in increased levels of multiple medications metabolized by the liver [19]. Clarithromycin appeared to increase the mean steady-state plasma theophylline concentration and AUC from 15.6 p.g/ml and 249 pg hr/ml, respectively, in the absence of clarithromycin, to 18.4 pg/ml and 291 pg hr/ml in the presence of clarithromycin p< 0.001 for both concentration and AUC). Although a modest increase was seen in the plasma theophylline concentration, the concentration remained within the therapeutic range, and concurrent administration of clarithromycin and theophylline was safe and well tolerated [121]. Although the magnitude of elevation in theophylline was small, caution should be used when... 

Scenarios of the future may be complicated by the possible use of multiple agents, or the delivery of chemical and replicating agents and/or their toxins that have been carefully matched, based on their stability and ability to generate specific symptoms. Health effects could be potentiated. Therefore, from a medical perspective, detection requires the availability of rapid diagnostic methods and procedures to assess illnesses that will be the result of multiple agents. 

Finally, physical workload is concerned with the use of the medical device and adds to user stress. Under high stress, the users of medical devices are distracted and have less time to make decisions (e.g., consider multiple device outputs). 

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