Adverse/Unwanted Reactions

All drugs, in addition to their therapeutic effects, have the potential to do harm, i.e. to cause adverse/unwanted reactions (side effects). These may or may not be related to the principal pharmacological action of the drug. Examples of the second category are toxic effects of metabolites of a drug or immunological reactions. 

From an examination of Equation 8.1, it can be seen that several things can be done to improve the heat-transfer rate. Quite often the simplest approach is to increase the temperature differential, by using higher-pressure steam or a hot oil supply. In some cases this may have adverse effects, for example a very hot wall temperature may lead to fouling, or, worse, initiate unwanted reactions. This is likely to be more pronounced in cases where mass transfer is poor. In some instances this practice may... 

For drugs already on the market, the discovery of inherited variants2 utilizes two unwanted effects of drugs adverse drug reactions (ADRs) and therapeutic failures. 

Data are available on the incidence of adverse effects of this drug (1-3). A review of published studies showed that about 13-15% of patients have adverse effects. The withdrawal rate because of unwanted reactions was 3.2-12% in short-term studies and 4% in one long-term trial. Adverse effects involved the gastrointestinal tract in 8-12% of patients, the central nervous system in 1-10% and the skin (rash, sweating, and itching) in 1-4%. Cutaneous photosensitivity and edema have also been reported. 

Any drug has the potential to cause an adverse effect. An adverse effect, be it an adverse drug reaction (ADR) or an adverse drug event, is an unwanted, unpleasant, noxious, or harmful consequence associated with the use of a medication that has been administered in a standard dose by the proper route, for the purpose of prophylaxis, diagnosis, or treatment. Death is the ultimate adverse drug event. 

These adverse drug reactions are generally dose-related and most can be predicted. They can be caused by an exaggeration of a drug s intended pharmacological effect or by an unwanted action or side effect. Type A adverse reactions are most likely to occur with drugs that have a steep dose-response curve (see Figure 3.1) and/or small therapeutic ratio (TR). 

Adverse experience (or event). A putative adverse drug reaction. Any unwanted medical event obtained during treatment with a drug. 

Adverse drug reactions. Proven unwanted side-effects due to treatment with a drug. They are conventionally classified into two sorts. Type A, which are due to a predictable pharmacological effect of the drug and are usually dose-dependent, and Type B, which are unpredictable (perhaps allergic) and are usually more serious and rarer. 

Both guidelines are based on a single compound approach for risk assessment, which implies some shortcomings. In real world situations there is always a mixture of several compounds (parent compounds, other chemicals and transformation products thereof). As known from pharmacy, the risk of unwanted side effects increases with the number of active compounds taken at the same time (polypharmacy). There are several concerns about polypharmacy, such as increased adverse drug reactions and drug-drug interactions. ... 

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