Ideal drug

An ideal" drug must be safe and effective. The mavimum daily dose should not exceed 200-300 mg. Drugs should be well absorbed orally and bioavailablc. Metabolic stability ensures a reasonable long half-life. Further on, a drug should be non-... 

In the case of drug design, it may be desirable to use parabolic functions in place of linear functions. The descriptor for an ideal drug candidate often has an optimum value. Drug activity will decrease when the value is either larger or smaller than optimum. This functional form is described by a parabola, not a linear relationship. 

Candidate protease inhibitor drugs must be relatively specific for the HIV-1 protease. Many other aspartic proteases exist in the human body and are essential to a variety of body functions, including digestion of food and processing of hormones. An ideal drug thus must strongly inhibit the HIV-1 protease, must be delivered effectively to the lymphocytes where the protease must be blocked, and should not adversely affect the activities of the essential human aspartic proteases. 

Figure 17.9 Schematic representation of the proposed activity profile of an ideal neuroleptic. The figure shows DA pathways to the prefrontal cortex, mesolimbic nucleus accumbens and striatum the effects required for an ideal drug on the DA influence and symptoms there and to what extent they are met by most typical and atypical neuroleptics and by clozapine. Note that while all atypical neuroleptics induce few extrapyramidal w side-effects (EPSs) few of them, apart from clozapine, have much beneficial effect in overcoming negative symptoms of schizophrenia ...

It appears that an ideal neuroleptic may need to reduce DA activity in the mesolimbic system (nucleus accumbens) to counter the positive symptoms of schizophrenia, increase it in the prefrontal cortex to overcome negative symptoms and have little or possibly no effect on it in the striatum so EPSs do not arise (Fig. 17.9). No wonder we still await the ideal drug. 

The other virtually uncontrollable term in Eq. (1) is D, the diffusion coefficient of the drug. For a spherical, ideal drug molecule in solution,... 

If one were to imagine the ideal drug-delivery system, two prerequisites would be required. First, it would be a single dose for the duration of treatment, whether it be for days or weeks, as with infection, or for the lifetime of the patient, as in hypertension or diabetes. Second, it should deliver the active entity directly to the site of action, thereby minimizing or eliminating side effects. This may necessitate delivery to specific receptors, or to localization to cells or to specific areas of the body. 

The answer is e. (Hardman, pp 858-874.) Because verapamil, a Ca channel blocker, has a selective depressing action on AV nodal tissue, it is an ideal drug for both immediate and prophylactic therapy of supraventricular tachycardia (SVT). Nifedipine, another Ca channel blocker, has little effect on SAT Lidocaine and adenosine are parenteral drugs with short ha If-lives and, thus, are not suitable for prophylactic therapy. Procainamide is more suitable for ventricular arrhythmias and has the potential for serious adverse reactions with long-term use. 

Although Li+ inhibits the synthesis of viral DNA in HSV-infected cells, it has no effect on that of the host cell DNA, making it an ideal drug for this infection. The synthesis of both viral and host cell polypeptides continues in, but is influenced by, the presence of Li+. In uninfected cells, the synthesis of the host cell polypeptides is unaffected by Li+. However in HSV-infected cells, the virus itself suppresses protein synthesis in the host and it appears that Li+ has the ability to reduce this suppression slightly [242]. Li+ has both stimulatory and inhibitory effects upon the synthesis of the viral polypeptides. For instance, the synthesis of HSV glycoprotein C is significantly decreased by approximately 90% by Li+ treatment. 

An ideal drug is potent, efficacious, and specific that is, it must have strong effects on a specific targeted biological pathway and minimal effects on all other pathways, to reduce side effects. In reality, no drugs are perfectly effective and absolutely safe. The aim of pharmacological studies is to obtain data on the safety and effectiveness of the lead compound. Many iterations of optimization of the lead compound may be necessary to yield a potential drug candidate for clinical trial. 

Statins are compounds that inhibit HMG-CoA reductase, the rate-limiting enzyme in cholesterol biosynthesis, and they are the world s best-selling drugs and are used for lowering cholesterol. Statins are well studied and are believed to be quite safe. Because they reduce the levels of cholesterol, the precursor of the bile acids, statins may be the ideal drugs to use for BA-loweiing in these GI tract diseases. 

The Ideal Drug from the Point of View of Pharmacokinetics... 

The above factors make caffeine the most widely consumed stimulant drug in the world. The stimulant and other basic biological properties of caffeine make it an almost ideal drug for many large corporations and small businesses to make large amounts of money. 

Although vasodilators would appear to be ideal drugs for the treatment of hypertension, their effectiveness, particularly when they are used chronically, is severely limited by neuroendocrine and autonomic reflexes that tend to counteract the fall in blood pressure. How these reflexes compromise the fall in blood pressure produced by the vasodilators is shown in Fig. 20.1. The diagram does not show all of the possible interrelationships but rather is meant to draw attention to the most prominent reflex changes. These reflexes include an augmentation of sympathetic nervous activity that leads... 

By the turn of the twentieth century, however, it was too late. Even with heroin in disrepute, it had already gained a strong foothold as a profitable worldwide commodity, and its production and trade could not be stopped. Heroin, even more so than opium, was an ideal drug for trade. Heroin, as a white powder, was lighter than opium, much more potent, and much... 

The development of sulfonamide carbonic anhydrase inhibitors was based on the observation that antibacterial sulfanilamides produce alkaline urine. This discovery led to the development of acetazolamide (8.29), a thiadiazole derivative. It is not an ideal drug because it promotes K+ excretion and causes a very high urine pH. Since chloride ions are not excreted simultaneously, systemic acidosis also results. Much more useful are the chlorothiazide (8.30) derivatives, which are widely used as oral diuretic drugs. These compounds differ from one another mainly in the nature of the substituent on C3 ... 

Enalapril maleate is an orally active angiotensin converting enzyme (ACE) inhibitor, it lowers peripheral vascular resistance without causing an increase in heart rate. The maleate salt (enalapril) allows better absorption after oral administration. It is an ideal drug for hypertensive patients who are intolerant to beta-blocker therapy. It also shows promise in the treatment of congestive heart failure. Following oral adminishation, enalapril is rapidly absorbed and hydrolysed to... 

From a pharmacokinetic perspective, proton pump inhibitors are ideal drugs they have a short serum half-life, they are concentrated and activated near their site of action, and they have a long duration of action. 

Ideal drug candidate for controlled release delivery systems. From a pharmacokinetic and pharmacodynamic perspective, the ideal drug candidate for controlled release delivery systems would have high potency and... 

From a pharmacokinetic perspective, proton pump inhibitors are ideal drugs they have a short serum half-life, they are concentrated and activated near their site of action, and they have a long duration of action. In contrast to H2 antagonists, proton pump inhibitors inhibit both fasting and meal-stimulated secretion because they block the final common pathway of acid secretion, the proton pump. In standard doses, proton pump inhibitors inhibit 90-98% of 24-hour acid secretion. 

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