Issues on HIV Pharmacotherapy in Developing Countries
Charles
Chiedza Maponga, Pharm.D., MHPE
Research Associate - ICHAPRT Director
Department of Pharmacy Practice
University at Buffalo
University of Zimbabwe
Email: cmaponga@buffalo.edu
Access to HIV Pharmacotherapy
The past two decades have seen worldwide therapeutic advances in research
on the Human Immunodeficiency Virus (HIV) and management of the Acquired
Immunodeficiency Syndrome (AIDS). Disparities however exist in the extent
of those advances between the developed and the developing world. In wealthy
nations antiretroviral drugs are now routinely used to significantly reduce
morbidity and mortality associated with HIV/AIDS while poor nations can
hardly access the drugs mainly due to their high cost. This is in spite
of the fact that the developing countries contribute over 90% of the HIV
burden.
The devastation caused by the HIV epidemic in the developing nations is
due to limited fiscal resources, scarce educational opportunities, and
inadequate infrastructure. These together with other epidemiological,
social, cultural, economic, political, and technological issues affect
HIV Pharmacotherapy implementation in developing countries. In order to
address these disparities, international collaboration is increasingly
being considered as a way of achieving equitable access to HIV Pharmacotherapy.
The Buffalo HIV Pharmacotherapy Network's International Center for HIV/AIDS
Pharmacotherapy Research and Training (ICHAPRT) is engaged in research and
training aimed at promoting rational distribution and use of HIV/AIDS and
other essential drugs in resource limited settings. Major areas that are
covered include pharmacoeconomics, pharmacogenomics, pharmacoinformatics
and pharmacoepidemiology.
ICHAPRT explores a comprehensive system of mutually supportive strategies
that have been shown to address the problem of equitable access to drugs such
as:
- Actively encouraging generic competition
- Seeking differential pricing of drugs from international suppliers
- Adopting World Trade Organization - Trade Related Intellectual Property
Rights safeguards into national legislation (making sure that all
legislation is in place)
- Creating high volume/high demand through global procurement
- Encouraging local drug production through licensing and technology transfer
- Evaluating the total cost of HIV management including drugs and exploring
the issue of financing considering the potential levels of contribution from
users fees, donors, government, and medical aid societies.
Quality and Bio-equivalence Surveillance
HIV/AIDS is currently a major killer disease in sub-Saharan African and
other parts of the developing world. Effective management of this public
health epidemic requires, among other measures, the use of effective and
good quality drugs. HIV/AIDS drugs are not yet used widely in public health
programs in the region. However, in most of the countries there is significant
utilization of these drugs within the private sector. Because of their
high costs, there is a great potential for substandard or counterfeit
products to appear on the market.
The World Health Organization's Essential Drugs and Medicines Policy
Department has already recognized the need for provision of good quality
antiretroviral drugs by taking steps to implement an HIV/AIDS Drugs Pre-qualification
program. That program is aimed at ensuring that medicines procured by
United Nation Agencies are only from inspected and certified suppliers.
That initiative is a positive step. However, it does not fully address
the problem of counterfeit drugs that normally originate from unknown
sources.
In developing countries, the need for routine monitoring of drug
concentrations is overshadowed by the need to decrease the cost of therapy.
However, serum drug concentration assaying may be justified for several
reasons. First, in order to access antiretrovirals in Africa the use of
more affordable generic products is being encouraged. This creates the
need to test and ensure that the generic products are bio-equivalent to
the innovator ones. Second, it is recognized that even if extensive studies
are being carried out in the developed countries, there might be population
and racially related differences that warrant additional pharmacokinetic or
pharmacogenomic studies in developing countries. Third, drug concentration
determination may be needed to determine patient adherence to therapy
regimens in cases of therapeutic failure, as an alternative to the currently
unavailable viral load, lymphocyte counts and resistance testing in the
resource limited environment. The drug levels might also need to be
determined in order to differentiate concentration depended versus non-concentration
dependent drug toxicities. Fourth the environmental conditions such as
temperature, humidity, and light that are known to affect the stability
of pharmaceuticals may affect products either during transportation or
storage leading to instability resulting in possible decreased efficacy
of the products.
Therefore, with the scarcity of laboratory support in developing countries,
there may be need for drug concentration determination and pharmacokinetic
interpretations within clinical settings for the purpose of differentiating
pharmacological from pharmaceutical failures. International research and
training that responses to the need for quality and bio-equivalence surveillance
systems in developing countries is currently being addresses under the
Buffalo HIV Pharmacotherapy Network's ICHAPRT.
Therapeutic Precision Assurance
The complexity of the relationship between virology, pharmacology, and
patient related factors create a significant challenge in HIV pharmacotherapy.
Success of antiretroviral therapy is strongly depended not only on access
to good quality pharmacological agents but also whether the patient is
capable of receiving them in a rational and accurate manner.
The science that deals with maximizing therapeutic efficacy while limiting
the chance of experiencing toxicities is collectively termed therapeutic
precision assurance. The Buffalo HIV Pharmacotherapy Network has developed
a number of these interventions and is in the process of developing
mechanisms to disseminate some of them internationally. Some of the already
developed and functional programs within the Network include:
- Patient adherence to therapy
- Resistance monitoring
- Adverse Drug Reaction monitoring
- Drug interaction (drug-drug, drug-food) alert
- Therapeutic drug monitoring (drug concentration assays)
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