**2. Rationale, objectives and methods**

Hypertension, also known as "high blood pressure" is currently the major risk factor for coronary heart disease (Roger VL. and others 2011) and cerebrovascular disease (stroke) (Roger VL. and others 2011; Twagirumukiza and others 2011). Already known as significant public health problem worldwide particularly in western societies (Kearney and others 2005), hypertension has been documented recently as real health threat in developing countries as well (Kearney and others 2005; Twagirumukiza and others 2011). Hypertension remains the leading reason for office visits in primary care (Pittrow and others 2004) in some western countries in contrast with developing countries where awareness is still low and where hypertensive patients reach health facilities rather for complications. This situation in developing countries, emphasizes the need of other approaches and strategies to avert the Non Communicable Diseases (NCDs) in general and the arterial hypertension morbidity and mortality in particular by targeting the lower level of the health system chain (De Maeseneer J. and others 2011).

On the other side, despite the availability of a wide range of antihypertensive drugs (Van Bortel and others 2011), blood pressure has remained poorly controlled in a majority of health

The Use of Antihypertensive Medicines in Primary Health Care Settings 133

more frequent and more severe: mainly heart failure (Mensah 2003) and stroke (Mufunda J and others 2006). In addition if developing world inhabitants survive to adulthood, hypertension-related disease may be the major cause of premature mortality (Twagirumukiza and others 2009b). The prevalence of hypertension has been well described worldwide (Kearney and others 2005) and in sub-Saharan Africa (Twagirumukiza and others 2011). The current figures and their projections remain overwhelming. Currently around 972 million people have hypertension worldwide (rising up to 1.6 billion in 2025) and more than 65% of them are in developing countries (Kearney and others 2005). The 2008 number of hypertensives in sub-Saharan Africa is estimated at 74.7 million (increasing by 68.0% in 2025(Twagirumukiza and others 2011)).The prevalence of hypertension in this region is estimated at 16.2%, being higher in urban than in rural regions (Twagirumukiza and others 2011). This prevalence adjusted to WHO standard population is similar to the

Table 1 shows that although the prevalence of hypertension was lower in sub-Saharan Africa than in England and USA, the prevalence of hypertension adjusted to the WHO standard population was higher in sub-Saharan Africa than in England and tended to be higher than in USA. However, the analysis of age-specific prevalence data shows that the hypertension prevalence is higher at younger ages (up to 35 years) in sub-Saharan Africa compared to the western countries, indicating that hypertension starts at earlier age in sub-Saharan Africa. The prevalence in old people is lower in sub-Saharan Africa than in western country. The plausible explanation is linked to low accessibility to treatment: by lacking adequate treatment people with hypertension at younger age died in earlier ages (around

There are evidences (Twagirumukiza and others 2011) of a clear difference in hypertension prevalence between countries. Different factors like diet habits (i.e. salt consumption) and genetic predisposition may play a role. As expected the prevalence of hypertension also increases with age and that prevalence was 50.7% higher in urban than in rural area. The influence of urbanization on hypertension was more pronounced in males than in females. These observations in rural versus urban areas are in line with other recent reports (Opie and Seedat 2005) reporting urban prevalence 1.5 to 2 times higher than rural ones. This difference can be influenced by the habits in rural which are dominated by routine field work as compared to urban lifestyle with more consumption of energy rich foods and a decrease in energy expenditure through less physical activity (Opie and Seedat 2005). However, modernisation (Dominguez and others 2006) may also transform rural settings themselves such as increasing use of automobiles leading to a decrease in physical activity, increasing overweight and obesity and more consumption of salt (Mufunda J and others

In sub-Saharan Africa setting, hypertension occurs earlier among adults of working age and its complications strike people at the top of their economic activity (Gaziano 2005; Twagirumukiza and others 2009b). Apart from the consequences on the quality of individual health, this leads to a large impact on a developing country's economic viability. In South Africa, for example, 2% to 3% of the country's gross national income, or roughly 25% of South African healthcare expenditures, was devoted to the direct treatment of

45-54 years). People with hypertension at older age are new cases or survivors.

2006; Reddy and Yusuf 1998) and tobacco (Jha P and Chaloupka F 1999).

cardiovascular disease (CVD) (Gaziano 2005; Pestana and others 1996).

prevalence in western countries (Table 1).

care settings, particularly in low resource settings. The access to medicines is highly driven by the availability and the cost of these drugs and strongly influences the prescription and usage patterns which in the end affect control of blood pressure(Twagirumukiza and others 2010). The rational use of available resources and the integration of the management strategies at primary health care level (De Maeseneer J 2009) have been advocated as key point of improving hypertension treatment (Twagirumukiza and Van Bortel 2011).

The aim of this chapter summarize the current knowledge on the use of antihypertensives in primary care and to provide an update to prescribers and health professionals in their daily questions about whom-and-how to treat –as far as arterial hypertension is concerned.
