Inhibitors categories

Reversible noncompetitive inhibition - The types of substances which can fit this inhibitor category need not look like a normal substrate. That s because they can bind to the enzyme whether the normal substrate is already bound or not. 

Or perhaps, within each inhibitor category, there may be a range of products all containing, say, phosphonates. Typically, for each inhibitor treatment in the range, the phosphonate type is upgraded, blended, or increased in concentration, which permits the inhibitor to perform under progressively higher levels of stress. 

As with individual treatment components, all inhibitor treatments within any inhibitor category (such as stabilized phosphate or zinc polymer phosphonate), from different vendors, cannot be considered to be the same Certainly there are similarities, but for each category, each particular vendor makes use of slightly different specialty raw materials and adjusts the formulation to meet particular market needs, performance demands, or pricing policies. Therefore care is required when trying to compare proposals ( apples with apples ). 

Quite often, a vendor will not promote a product on the basis of a particular inhibitor category but rather, may promote the benefit of an individual component within the product (such as the ability of a constituent polymer to control soluble iron) and across product categories. So, a range of products within different categories, may therefore be marketed under a particular brand name that is common to all inhibitors containing the same iron polymer. 

Selection of an inhibitor must therefore be made carefully while keeping in mind these characteristics. Several phenolic compounds may have the right profile in each inhibitor category and not effecting the quality and cost of monomer production. Amongst other things, this explains the success of phenolic inhibitors in the vinyl monomer industry. 

Enzyme action is frequently accelerated or retarded by the presence of other substances both organic and inorganic. Such substances have been divided into three categories (a) co-enzymes, without which certain enzymes are unable to function (i) activators, and (c) inhibitors. 

Herbicidal Inhibition of Enzymes. The Hst of known en2yme inhibitors contains five principal categories group-specific reagents substrate or ground-state analogues, ie, rapidly reversible inhibitors affinity and photo-affinity labels suicide substrate, or inhibitors and transition-state, or reaction-intermediate, analogues, ie, slowly reversible inhibitors (106). 

Treatment of Major Depression. Dmgs commonly used for the treatment of depressive disorders can be classified heuristicaHy iato two main categories first-generation antidepressants with the tricycHc antidepressants (TCAs) and the irreversible, nonselective monoamine—oxidase (MAO) inhibitors, and second-generation antidepressants with the atypical antidepressants, the reversible inhibitors of monoamine—oxidase A (RIMAs), and the selective serotonin reuptake inhibitors (SSRIs). Table 4 fists the available antidepressants. 

To be used effectively, the inhibitor must be compatible with the expected environment and also be economical, while contributing the greatest desired effect. Inhibitors can be classed into two main categories, inorganic and organic inhibitors. 

These dm are contraindicated in patients with a hypersensitivity to the dragp and during pregnancy (Category C) and lactation. Tolcapone is contraindicated in patients with liver dysfunction. The COMT inhibitors are used with caution in patients with hypertension, hypotension, and decreased hepatic or renal function. 

The cholinesterase inhibitors are contraindicated in patients with a hypersensitivity to the dru and during pregnancy (Pregnancy Category B) and lactation. 

Category X) and lactation. The HMG-CoA reductase inhibitors are used cautiously in patients with a history of alcoholism, acute infection, hypotension, trauma, endocrine disorders, visual disturbances, and myopathy. 

The proton pump inhibitors are contraindicated in patients who have hypersensitivity to any of the drags. Omeprazole (Pregnancy Category C) and lansoprazole, rabeprazole, and pantoprazole (Pregnancy Category B) are contraindicated during pregnancy and lactation. The proton pump inhibitors are used cautiously in older adults and in patients with hepatic impairment. 

Fig. 1 Heterocycles bearing a 2-pyridone moiety with wide range of medicinal applications. Amrinone WIN 40680 1 is a cardiotonic agent for the treatment of heart failure. ZAR-NESTRA 2 is a selective farnesyl protein inhibitor and NP048 3 is a pilicide with novel antibacterial properties. The 2-pyridones 4, 5 and 6 are schematic representations of the three categories of 2-pyridones that wiU be covered in this chapter i.e., substituted 2-pyridones 4, 2-quinolones 5 and other ring-fused 2-pyridones 6...

A large number of in vitro inhibitors of PAL are known, however, few of these effectively inhibit PAL activity in vivo without also causing phytotoxic effects unrelated to their effects on PAL. PAL inhibitors fall into four categories 1) PAL product-inhibitors such as t-cinnamic acid and p-coumaric acid (e.g. 35) ... 

Altered removal of a neurotransmitter from the synaptic cleft. The third mechanism by which drugs may alter synaptic activity involves changes in neurotransmitter reuptake or degradation. A very well known example of a drug in this category is Prozac (fluoxetine), which is used to treat depression. The complete etiology is unknown, but it is widely accepted that depression involves a deficiency of monoamine neurotransmitters (e.g., norepinephrine and serotonin) in the CNS. Prozac, a selective serotonin reuptake inhibitor, prevents removal of serotonin from the synaptic cleft. As a result, the concentration and activity of serotonin are enhanced. 

---