Guidelines for achieving marketing approval of drugs intended for special groups - including pregnant women, children, elderly and ethnic minorities- are needed to identify differences in drug and biological activity in subgroups. Absorption, distribution, metabolism and excretion can be affected, resulting in differing pharmacokinetic, pharmacodynamic, safety and efficacy profiles. Dosage may vary, resulting in either under- or over-dosing. There are a few existing published regulations and guidelines which could be adapted and integrated into regional education and training activities.
In Nigeria, the population of children under 15 years is 47%; in Viet Nam, it is almost 20%. Paediatric patients should be given medicines only when they have been appropriately evaluated for their use. This involves conducting special types of studies in various age categories and includes pharmacokinetics, pharmacodynamics, efficacy, safety and ethical considerations.
ICH Guidelines for Clinical Investigation of Medicinal Products in the Paediatric Population are currently in draft form. These guidelines provide an outline of critical issues in paediatric drug development and approaches to the safe, efficient and ethical study of medicinal products in the paediatric population. Some issues in production and labelling of these drugs include suitable dosage forms (e.g. granules, suppositories, solution), suitable dose, convenient route of administration, reasonable design and appropriate packaging.
Guidelines for geriatric populations have been approved for ICH countries. The total population of older persons will increase significantly in the coming years in Europe, Japan and the USA. The use of drugs in this population requires special consideration, due to the frequent occurrence of underlying diseases, concomitant drug therapy and the consequent risk of drug interaction.
In this connection, pharmacokinetic studies, particularly in renally- or hepatically-impaired subjects, are most important. Drug interaction studies are equally essential, because of polypharmacy and OTC use in this population. Other practical problems which must be addressed in the use of drugs in geriatric populations include difficulty in swallowing and hearing, as well as memory loss.
Pregnant women also require special guidelines, although none are currently available. Physiological changes of pregnancy influence pharmacokinetics and may affect dosage. Guidelines should also be directed to assuring the safety of use and specific warnings. Ethnic minorities and other special populations must rely on national pharmacovigilance systems.