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Patients; Drug; Pharmacodynamics; Regimens; Physicians; Medication;

Introduction

The risk of dementia increases steadily with the number of medications used and age in older people as described in a study in Taiwan. In another study of the frequency of polypharmacy with three or more medications at hospital discharge for bipolar disorders or unipolar depression, polypharmacy increased from patients. Another study regarding the development of Acute Renal Failure as a result of polypharmacy indicated that relative to patients who received polypharmacy for less than 30 days, those who received polypharmacy for over few days had odds ratios of developing ARF, respectively [1]. Drug interactions play a very important role in the development of polypharmacy and can be defined as the modulation of the pharmacologic activity of one drug by the prior or concomitant administration of another drug. It is also defined as an interaction which occurs when the effects of one drug are changed by the presence of another drug. The causes and significance of drug interactions are multifaceted and include drug dose, serum drug level, route of administration, drug metabolism, duration of therapy, and patient factors, such as age, gender, weight and genetic predisposition. Drug interactions are often classified as either pharmacodynamics or pharmacokinetic interactions [2]. Pharmacodynamics interactions include those that result in additive or antagonistic pharmacological effects. Pharmacokinetic interactions involve induction or inhibition of metabolizing enzymes in the liver or elsewhere, displacement of drug from plasma protein binding sites, alterations in gastrointestinal absorption, or competition for active renal secretion [3]. The frequency and prevalence of interactions is dependent upon the number of concomitant drugs and the complexity of the regimens. The prevalence is also dependent upon other variables, such as patient adherence, hydration and nutritional status, degree of renal or hepatic impairment, smoking and alcohol use, genetics and drug dosing. Additionally, some patients may exhibit evidence of a particular drug interaction, while others with the same drug combination do not. The addition of nonprescription medications plays a very important role in causing ADRs. Some studies indicate that patients aged years use on average prescribed medications, and non-prescribed medications. It is a well-established fact that non-prescription medications are most commonly used among the geriatric population. A drug combination may sometimes cause synergistic toxicity, which is greater than the sum of the risks of toxicity of either agent used alone [4]. Patient’s concurrently receiving corticosteroids and NSAIDs had a risk of peptic ulcer disease that was greater than that of nonusers of either drug. The concurrent use of antidepressants, hypnotics, anti-epileptics and antihistamines may lead to more drowsiness. Both vancomycin and narcotics induce dosedependent skin reactions and synergize to cause adverse reactions. Prescribing cascade occurs when patients take a medication and suffer from some adverse drug reactions that are misdiagnosed by the physicians as symptoms of a disease, requiring more medication [5]. This condition may lead to either worsening of the ADR or putting patients at risk of new ADRs. Anti-hypertensive, Sedatives, Opioids, NSAIDs, Anti-epileptics, Antibiotics and herbal medications are some of the most frequently prescribed drugs. The cascades include the use of prochlorperazine to prevent drug-induced dizziness, antihypertensive to treat NSAID-induced hypertension and levodopa to manage metoclopramide-induced movement disorder. Prochlorperazine for instance may cause postural hypotension which may exacerbate any hypotensive effect of antihypertensive drugs. This cascade might be the cause of hip fracture following the use of prochlorperazine. ACEIs induced cough may be misinterpreted as a chest infection and given antibiotics and cough suppressant. Thiazide diuretics may cause hyperuricemia which leads to prescribing colchicine which in turn may cause diarrhoea. Erythromycin may cause arrhythmia and be misinterpreted as a disease and given anti-arrhythmics. Anti-epileptics may cause a rash which leads to corticoid use [6]. Using therapeutic equivalents to treat the same illness is considered one of the causes of ADRs, two analgesics, antihistamine with other sedative drugs or two anti-hypertensive are some examples of using two medications which exhibit the same action. Lack of co-ordination between physicians, pharmacists and patients can in turn lead to redundancy, using the same medications under different brand names. This will increase the risk of ADRs. Finally; some studies indicate that polypharmacy might affect the nutritional status of patients which leads to malnutrition which is more pronounced among the older population. Polypharmacy should be looked at seriously in order to prevent potential ADRs which affect patient health status, compliance and therapeutic outcomes [7]. Drug dosing affects the development of ADRs in many ways, e.g. some drugs need to be given in the morning and others in the evening, some at bedtime. Taking Bisphosphonates at bed time may lead to esophagitis, the antiplatelet effect of aspirin when taking in the evening is more potent that in the morning. Dosing needs to be considered as a factor which might have some effect on the development of ADRs. Concomitant patient’s disease may also influence susceptibility to ADRs. For example; increases of the frequency of idiosyn-cratic toxicity with anti-infective drugs such as trimethom-prim-sulphamethoxazole. Multiple diseases make patients more vulnerable to ADRs due to the presence of many diseases and the use of many drugs. If hyper-tension is accompanied with other diseases, these diseases might have an impact on the response of the body to antihypertensive drugs since the metabolic processes of the body will be affected negatively. In patients with renal failure, the effect of drugs on the kidneys is lessened because of the loss of the site of action for these drugs. This leads to increasing the dose which in turn leads to more ADRs. The same issue occurs in patients with peptic ulcer disease, many drugs including NSAIDS when prescribed, may lead to serious medical problems. Multiple diseases are a very important factor which causes drug-disease interactions and ADRs [8]. Drugs that are helpful in one disease are harmful in another. For example, some beta-blockers taken for heart disease or high blood pressure can worsen asthma and make it hard for people with diabetes to tell when their blood sugar is too low. Some drugs taken to treat a cold may worsen glaucoma. Diabetes, high or low blood pressure, an ulcer, glaucoma, an enlarged prostate, poor bladder control, and insomnia are particularly important, because people with such diseases are more likely to have drug-disease interactions. Certain drugs have the capability to exacerbate acute and/or chronic disorders. These drugs can also blunt the typical signs and symptoms of a hypoglycaemic reaction in diabetic patients and alter insulin utilization in the body. These drugs and calcium channel blockers, particularly verapamil, have negative inotropic and negative chronotropic effects on the heart and can exacerbate diseases such as congestive heart failure. Prednisone can aggravate congestive heart failure and cause fluid retention. Because some of these interactions may have an insidious onset, careful and close medical attention is mandatory [9]. AIDS for instance worsen ADRs, the incidence of Stevens Johnson syndrome and toxic epidermal necrolysis has been reported to be higher among those particular patients. A study shows that one of the medications taken among patients who developed is trimethoprim. According to a recent study of a multivariate logistic regression indicated that a increased the risk of hepatotoxicity by a factor and that co-infection with hepatitis B or C virus increased this risk by a factor. Different factors affect the development of ADRs in different degrees; some of these factors have a direct effect on ADRs. Serious attention to these factors will result in preventing or reducing the occurrence of unwanted drug actions which could have been avoided if health care providers spent enough time to pinpoint these problems. Health education, counselling and reconciliation are tools that must be utilized by pharmacists. Information technology should also be part of the medication decision making process which provides health professionals with up to date knowledge of drug-dosing, interaction, ADRs and other important information needed to use medication in the optimum manner. The elderly should also be the focus of the pharmacist, because they form the majority of those who uses polypharmacy. Finally; for each benefit to come out of a medication there is always a possibility for some risks; benefits should always out weight risks for the purpose of providing the best treatment with the least number of medications at the most economic price. Many factors play a crucial role in the occurrence of ADRs; some of these are patient related, drug related or socially related factors [10]. Age for instance has a very critical impact on the occurrence of ADRs, both very young and very old patients are more vulnerable to these reactions than other age groups. Alcohol intake also has a crucial impact on ADRs. Other factors are gender, race, pregnancy, breast feeding, kidney problems, liver function, drug dose and frequency and many other factors.

Conclusion

The effect of these factors on ADRs is well documented in the medical literature. Taking these factors into consideration during medical evaluation enables medical practitioners to choose the best drug regimen.

Acknowledgement

None

Conflict of Interest

None

1. Maroon JC, Bost JW, Borden MK, Lorenz KM, Ross NA, et al. (2006) . Neurosurg Focus US 21: 1-13.

,

2. Birnesser H, Oberbaum M, Klein P, Weiser M (2004) . J Musculoskelet Res EU 8: 119-128.

,

3. Świeboda P, Filip R, Prystupa A, Drozd M (2013) . Ann Agric Environ Med EU 1: 2-7.

,

4. Nadler SF, Weingand K, Kruse RJ (2004) . Pain Physician US 7: 395-399.

, ,

5. Trout KK (2004). J Midwifery Wom Heal US 49: 482-488.

, ,

6. Cohen SP, Mao J (2014) . BMJ UK 348: 1-6.

, ,

7. Ozgoli G, Goli M, Moattar F (2009). J Altern Complement Med US 15: 129-132.

, ,

8. Raeder J, Dahl V (2009) . CUP UK: 398-731.

, ,

9. Mello RD, Dickenson AH (2008) . BJA US 101: 8-16.

, ,

10. Bliddal H, Rosetzsky A, Schlichting P, Weidner MS, Andersen LA, et al. (2000) . Osteoarthr Cartil EU 8: 9-12.

, ,