Biological systems therapeutic effects

Mechanism of Action A biologic response modifier that stimulates the immune system, Therapeutic Effect Inhibits hepatitis C virus. 

In general, receptor theory uses indirect mathematical models to estimate descriptors of drug effect. These descriptors still must be used with the proviso that biological systems may still modify drug effect in a system-dependent manner and thus predictions of therapeutic effect must be made with caution across different systems. 

Because pharmaceuticals are intended to affect the functioning of biological systems, and safety assessment characterizes the effects of higher-than-therapeutic doses of compounds, it is essential that one be able to differentiate between hyperpharmacology and true (undesirable) adverse effects. 

In the area of bioengineered products, many of which are complex proteins of potent but sparsely studied activities in living systems, the investigative responsibilities of the toxicologist are likely to be very important, because he/she may be the first observer able to study the effects of repeated administration of a range of doses on a living system. It is now possible to frame a classification of the types of biologically derived therapeutic products (Table 12.3). 

It is clear that to exert a toxic effect a compound must come into contact with the biological system under consideration. It may exert a local effect at the site of administration on initial exposure, but it must penetrate the organism in order to have a systemic effect. The most common means of entry for toxic compounds are via the gastrointestinal tract and the lungs, although in certain circumstances, absorption through the skin may be an important route. Therapeutic agents may also enter the body by other routes such as injection. 

Immunotherapy with fungal extracts has often been associated with a high frequency of systemic side effects. It was shown that high doses of Cladosporium extract (top doses of 100,000 biological units) resulted in an improved therapeutic effect [22]. According to preliminary data from Norman and Lichtenstein [26], the elicitation of mild side effects was even intended and considered to indicate that this would result in increased clinical efficacy. Tuchinda and Chai [27] reported similar observations fox Altemaria. 

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