1.1 Introduction
An antihypertensive drug is a medication used to treat high blood pressure (hypertension). These drugs work by relaxing blood vessels, reducing the heart's workload, and helping to lower blood pressure to safer levels (Cunningham et al., 2018). Hypertension, commonly known as high blood pressure, is a significant global health concern due to its role in the development of various cardiovascular diseases, including stroke, heart failure, and kidney disease (World Health Organization [WHO], 2021). Antihypertensive drugs, such as calcium channel blockers, are frequently prescribed to manage this condition by helping to lower blood pressure and reduce the risk of associated complications (Bauersachs & Haller, 2016). Nifedipine, a widely used calcium channel blocker, is known for its ability to relax vascular smooth muscles, thereby promoting vasodilation and lowering blood pressure (Niaz et al., 2017).
This chapter will address the background information that motivated this study, the challenges that prompted it, its aim, and its objectives as a preface to subsequent sections of the study. Additional factors include the study's significance, scope, limitations, research questions, and the definition of technical terms.
1.2 Background of Study
Hypertension, often referred to as the "silent killer," has been recognized as a major risk factor for cardiovascular diseases for centuries. The understanding of its impact on health, as well as the need for effective treatment options, evolved significantly throughout the 20th century. Initially, hypertension was managed with lifestyle changes, but the development of antihypertensive drugs revolutionized treatment. Among these, calcium channel blockers (CCBs) like nifedipine emerged in the 1980s as effective drugs for controlling blood pressure and preventing complications associated with hypertension, such as stroke and heart failure (Bauersachs & Haller, 2016).
Nifedipine, first introduced in the 1980s, is a widely used antihypertensive drug. It works by inhibiting calcium ions from entering the smooth muscle cells of the heart and blood vessels, promoting vasodilation and subsequently lowering blood pressure (Niaz et al., 2017). Its clinical use became prominent due to its rapid onset of action and relative safety profile compared to other antihypertensive agents available at the time. While nifedipine's effectiveness in reducing blood pressure has been well documented, the long-term effects of the drug on various biochemical parameters have attracted significant attention. Research on the systemic effects of nifedipine began to gain traction as clinical studies raised concerns about its impact on vital organs such as the liver and kidneys, as well as its influence on lipid metabolism and electrolytes (Mullins et al., 2018). Many studies involving animal models, particularly rats, were conducted to evaluate how long-term administration of nifedipine affects these biochemical parameters.
Hypertension, also known as high blood pressure, is a chronic medical condition that affects a significant portion of the global population. It is one of the leading causes of cardiovascular diseases, including stroke, coronary artery disease, and kidney failure (World Health Organization [WHO], 2021). Management of hypertension is crucial to reducing the incidence of these complications, and antihypertensive medications play a pivotal role in controlling blood pressure and improving overall cardiovascular health. Among the various classes of antihypertensive drugs, calcium channel blockers (CCBs) are widely used due to their ability to block the influx of calcium ions into vascular smooth muscle cells, which results in vasodilation and reduced blood pressure (Bauersachs & Haller, 2016).
Nifedipine is one of the most commonly prescribed calcium channel blockers. It is primarily used for managing hypertension and angina pectoris, as it promotes the relaxation of blood vessels, leading to reduced peripheral vascular resistance and, consequently, lower blood pressure (Niaz et al., 2017). While nifedipine has proven clinical efficacy, the long-term effects of the drug on various biochemical parameters in the body are not fully understood, especially with regard to its potential side effects.
Biochemical parameters, such as liver enzymes, kidney function markers, lipid profiles, and electrolytes, are important indicators of the body's metabolic and organ health. Alterations in these parameters could signify underlying systemic effects, particularly with long-term use of medications like nifedipine. Previous studies have shown that antihypertensive drugs, including calcium channel blockers, may influence renal and liver function, lipid metabolism, and electrolyte balance (Mullins et al., 2018).
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to know the effect of an antihypertensive drug - nifedipine on some biochemical parameters in rats.
1.3 Statement of Problems
Investigation revealed that hypertension is a prevalent health condition that affects millions of individuals worldwide, contributing significantly to the burden of cardiovascular diseases. While antihypertensive drugs, including calcium channel blockers like nifedipine, are widely prescribed to manage high blood pressure, their long-term effects on the body remain an area of concern.
Nifedipine is particularly effective in reducing blood pressure by promoting vasodilation; however, the potential impact of this drug on various biochemical parameters in the body, such as liver function, kidney function, electrolyte balance, and lipid metabolism, has not been fully explored. Though nifedipine is considered safe and effective in treating hypertension, there is limited research on how it affects critical biochemical markers over prolonged use, especially in animal models like rats.
Alterations in these biochemical parameters could signify potential adverse effects on the body's metabolic systems. Such effects may include liver enzyme changes, kidney dysfunction, electrolyte imbalance, and variations in lipid profiles, which may go unnoticed in clinical practice unless properly studied.
1.4 Aim and Objectives of Study
The aim of the study is to investigate the effect of the antihypertensive drug nifedipine on various biochemical parameters in rats. In achieving this aim, the following specific objectives were laid out as follows:
- To evaluate the impact of nifedipine on liver function by measuring enzyme activities such as alanine aminotransferase (ALT) and aspartate aminotransferase.
- To assess the effects of nifedipine on kidney function by examining parameters such as serum creatinine and blood urea nitrogen (BUN).
- To determine the influence of nifedipine on lipid metabolism, particularly changes in cholesterol levels, triglycerides, and high-density lipoprotein (HDL).
- To analyze the effects of nifedipine on electrolyte balance, including sodium, potassium, and calcium concentrations in the blood.
- To compare the biochemical parameters in rats treated with nifedipine to those in control groups, in order to identify any significant changes or adverse effects of the drug on overall metabolic health.
1.5 Research Questions
The study came up with research questions so as to be able to ascertain the above stated objectives. The specific research questions for the study are stated below as follows:
- Are there significant differences in the biochemical parameters between rats treated with nifedipine and those in the control group?
- How does nifedipine administration affect liver enzyme activities, specifically alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in rats?
- What impact does nifedipine have on kidney function, as measured by serum creatinine and blood urea nitrogen (BUN) levels in rats?
- How does nifedipine influence lipid metabolism, particularly cholesterol, triglycerides, and high-density lipoprotein (HDL) levels in rats?
- What are the effects of nifedipine on electrolyte balance, including sodium, potassium, and calcium concentrations in the blood of rats?
- What are the short- and long-term biochemical changes induced by nifedipine administration in rats, and how do these changes inform its safety profile for human use?
- How do the biochemical effects of nifedipine compare to other antihypertensive drugs in terms of liver, kidney, lipid, and electrolyte balance in rats?
1.6 Research Hypothesis
In order to pursue the objective of this study, the following generalized statements have been designed to guide and aids in obtaining the result for the experiment to be conducted. For this work, the null hypothesis will be represented with H0 while the alternative hypothesis will be represented with hypothesis H1.
- H0: Nifedipine administration will have no significant effect on biochemical parameters, including liver enzyme activities (ALT and AST), kidney function markers (serum creatinine and BUN), lipid profile (cholesterol, triglycerides, and HDL), and electrolyte balance (sodium, potassium, and calcium) in rats, compared to the control group.
- H1: Nifedipine administration will significantly alter biochemical parameters, including liver enzyme activities (ALT and AST), kidney function markers (serum creatinine and BUN), lipid profile (cholesterol, triglycerides, and HDL), and electrolyte balance (sodium, potassium, and calcium) in rats, compared to the control group.
1.7 Significance of Study
The findings will contribute to a deeper understanding of how nifedipine influences key metabolic functions such as liver enzymes, kidney function, lipid metabolism, and electrolyte balance. This knowledge will be critical in evaluating the safety and long-term effects of nifedipine, particularly in terms of its impact on vital organs and metabolic processes.
The study will also aid in assessing the therapeutic efficacy of nifedipine and its potential risks, providing a foundation for more informed clinical decision-making. Furthermore, the research will help identify any adverse biochemical changes that may arise from prolonged use of nifedipine, ultimately guiding the development of safer and more effective antihypertensive treatment protocols.
1.8 Justification of Study
This study is justified by the need to better understand the biochemical effects of nifedipine, a widely used antihypertensive drug. While nifedipine is commonly prescribed for managing hypertension, its long-term impact on various biochemical parameters, such as liver function, kidney health, lipid profiles, and electrolyte balance, is not fully understood. The results of this study will provide critical information about the drug's safety profile, helping to identify any potential adverse effects that may arise from its prolonged use.
Furthermore, this research will contribute to the broader knowledge of how antihypertensive medications affect metabolic processes, which is essential for the development of safer and more effective treatment protocols.
Additionally, the findings will help bridge the gap between basic scientific research and clinical applications, ensuring that hypertension treatments are both effective and safe for long-term use.
1.8 Scope of Study
The scope of the research is focused on the effect of an antihypertensive drug - nifedipine on some biochemical parameters in rats.
1.9 Limitations of the Study
During the course of this study, there were some problems encountered which stood as limitations to the research work. Some of the limitations include:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet, questionnaire and interview).
1.10 Definition of Terms
Antihypertensive Drug: An antihypertensive drug is a medication used to treat high blood pressure (hypertension). These drugs work by relaxing blood vessels, reducing the heart's workload, and helping to lower blood pressure to safer levels. Nifedipine, the focus of this study, is a calcium channel blocker commonly prescribed to manage hypertension and angina (chest pain) (Cunningham et al., 2018).
Biochemical Parameters: Biochemical parameters refer to various measurable substances or processes in the body that provide information about an organism's health status. In this study, biochemical parameters include markers of liver function, kidney function (such as creatinine and urea), lipid profiles (cholesterol, triglycerides), and electrolyte balance (sodium, potassium). These parameters help assess the physiological effects of drugs on internal organs (Sanni & Oladipo, 2020).
Nifedipine: Nifedipine is a drug that belongs to the class of calcium channel blockers. It works by inhibiting calcium ions from entering the smooth muscle cells of blood vessels, thereby causing vasodilation and a reduction in blood pressure. It is often prescribed for the treatment of hypertension and certain heart conditions (Beresford, 2017).
Hypertension: Hypertension, commonly known as high blood pressure, is a condition where the force of the blood against the walls of the arteries is consistently too high. It is a major risk factor for cardiovascular diseases, strokes, and kidney damage (National Heart, Lung, and Blood Institute, 2019).
Liver Enzymes: Liver enzymes, such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST), are proteins found in liver cells that play key roles in metabolizing substances. Elevated levels of these enzymes often indicate liver damage or dysfunction (Koopmans et al., 2016).
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