Theories of Drug Activity

Although there is no single uniform theory that can explain the activity of drugs, several theories have been advanced over the years in attempts to elucidate drug action. In general we may consider pharmacological action to be of two types. One type is thought to be caused solely by the physicochemical properties of the compound without discernible relationship to chemical structure. These structurally nonspecific drugs are usually administered in relatively large doses. It is presumed that...

Psychoactive Drugs Chemotherapy of the Mind

It is difficult to exaggerate the complexity of the human brain's chemistry and functions, many of which are only beginning to be understood. Much is still undiscovered. Before embarking on a discussion of mental diseases and mechanistic aspects of the drugs used in their treatment, it is important to define certain terms frequently encountered. Psychosis. A mental disorder of sufficient magnitude to result in personality breakdown and loss of contact with reality. Delusions and hallucinations...

Factors Affecting Bioactivity

Factors Affecting Bioactivity

The biochemical systems encountered by a drug molecule are extremely complex. Therefore, it should not be surprising that the factors affecting the drug's interactions and contributing to its final effect are also manyfold. The factors may be divided into three categories 1. Physicochemical properties such as solubility, partition coefficients, and ionization. 2. Chemical structure parameters such as resonance, inductive effect, oxidation potentials, types of bonding, and isosterism. 3. Spatial...

Topliss Decision Tree In Drug Designing

Square brackets indicate alternates. Asterisk indicates compared with 4-H compound. Figure 1-10. Topliss decision tree. M, more active E, equiactive L, less active. equations can be rapidly calculated.8 This procedure gives useful correlations by both methods in most situations and has been shown to give comparable results. No doubt other refinements and approaches will be made to quantify structure-activity relationships of drugs to help design new agents...

Carcinolytic Antibiotics

A clinically important group of anticancer drugs are certain cytotoxic antibiotics that inhibit DNA and or RNA synthesis by complexing with DNA via an interposing reaction called intercalation. The process is now understood to be one by which the planar, poly-cyclic portions of some drugs can slide into the double helical DNA structure in a horizontal manner by interposing between the base layers of DNA, which are stacked at distances of 3.36 A above each other. Interactions between the purine...

Hypolipidemic Hypocholesterolemic Drugs

The fact that even young men can develop atherosclerosis was reported following autopsies of German soldiers during World War I. However, it was a U.S. Armed Forces Institute of Pathology report toward the end of the Korean War (Enos et al., 1953) showing that young men (average age 22) had evidence of coronary heart disease (CHD) that made the medical profession take note of the epidemic that was CHD. The problem is still extensive in spite of considerable, but slow, progress since the 1950s....