Side effects, drug, defined

As with all drugs, the specific side effects of the quinolones must be considered when they are chosen for treatment of bacterial infections [5]. Reactions of the gastrointestinal tract and the central neivous system are the most often observed adverse effects during therapy with quinolones. It should be underlined, however, that compared with many other antimicrobials, diarrhea is less frequently observed during quinolone treatment. Antibiotic-associated colitis has been observed rarely during quinolone therapy. Similarly, hypersensitivity reactions, as observed during therapy with penicillins and other (3-lactams, is less frequently caused by quinolones. Some other risks of quinolone therapy have been defined and must be considered if a drug from this class is chosen for treatment of bacterial infections. 

Synonyms of adverse reactions generally include adverse medical effects, untoward effects, side effects, adverse drug experiences, and adverse drug reactions. Specific distinctions among some of these terms may be defined operationally. For example, the term adverse reaction is used to denote those signs and symptoms at least possibly related to a medicine, whereas the term adverse experience is used to include nonmedicine-related medical problems in a trial such as those emanating from trauma or concurrent illness. Distinctions among side effects, adverse events, and adverse reactions are illustrated in the definitions of the two former terms. 

This leaves hydralazine as the only drug of this kind available to date on the U.S. market for chronic use. The total picture of the mechanism of action of hydralazine is still not clearly defined but there is general agreement that direct relaxation of the vasculature leading to reduced peripheral resistance is the principal component of its mechanism of action. This drug has stood the test of time despite such side effects as headache, tachycardia and a syndrome which resembles acute systemic lupus erythematosus, often called "hydralazine syndrome" (1). 

TCAs derive their name from their chemical structure aU tricyclics have a three-ring nucleus. Currently, most clinicians are moving away from using TCAs as first-line drugs relative to the newer antidepressants, they tend to have more side effects, to require gradual titration to achieve an adequate antidepressant dose, and to be lethal in overdose. Some data suggest that TCAs may be more effective than SSRIs in the treatment of major depression with melancholic features (Danish University Antidepressant Group 1990 Perry 1996) however, many skilled clinicians and researchers continue to prefer the newer antidepressants, even for patients with melancholia, for the aforementioned reasons. Newer medications that affect both norepinephrine and serotonin (e.g., venlafaxine and mirtazapine) also may have superior efficacy in severely iU depressed patients or when remission is defined as the outcome (Thase et al. 2001). 

Usually utilities are presented as a single unit value for a defined disease state. They reflect the physical, mental and social aspects of the disease. The intent is to come up with a single number that reflects the person s experience of a disease state. Generally defined disease states are descriptions of normal (unimpaired), mild, moderate or severely impaired states of a disease or symptom. The utilities attached to them can represent specific aspects of the disease experiences. For example, utilities can be measured for a specific drug-induced side effect. 

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