Prevalence of Adverse Drug Reactions

Even for established excipients, regulators will look carefully at their presence in new drug formulations because they are not necessarily inert materials and some have well-established activity and/or toxicity. Clinically relevant adverse reactions are known for well-known excipients and the subject is covered elsewhere in the published literature (2,20,75-81). Findings tend to be uncommon compared to the overall prevalence of adverse drug reactions and often involve hypersensitivity reactions that are not likely to be predicted by conventional toxicity studies. 

Despite the prima facie attraction of cultural convergence in medicine, there are not only major differences in the incidence and prevalence of many diseases between countries but also in expectations of these different cultural groups of patients. Even in a relatively homogeneous region such as Western Europe, the incidence of adverse drug reactions to a standard therapy varies dramatically from country to country. The perception of... 

Tile usefulness of amphotericin B is limited by a high prevalence of adverse reactions. Nearly 80% of patient-treated with amphotericin B develop nephrotoxicity. Fever headache, anorexia, gastrointestinal distress, malaise, and muscle and joint pain arc common. Pain at the site of injection and thrombophlebitis are frequent complications of intravenous administration. The drug must never be administered intramuscularly. The hemolytic activity of amphotericin B may be a consequence of its ability to Icadi cholesterol from erythrocyte cell membranes. 

It is well documented that certain viral infections are associated with the induction and/or exacerbation of allergic reactions [84-86]. Moreover, infection with HCV, HAV and HBV can be associated with increased IgE levels [30, 31] and certain allergic manifestations [28]. In addition, HIV-1 infection can be associated with increased IgE levels [33-42] and augmented prevalence of adverse reactions to drugs and urticarial rash [47-48], Similarly, certain bacterial infections (e.g. S. aureus) can exacerbate atopic dermatitis [62-64], certain forms of allergic rhinitis [65, 66], and asthma [87], Therefore, it appears that viral and bacterial infections can be involved in the induction and/or exacerbation of respiratory and skin allergies. 

Adverse reactions to sulfites appear to occur mainly among a small percentage of asthmatics, but it is possible for individuals without asthma to be sulfite sensitive. It is typically more of a problem in individuals with severe asthma who are also taking corticosteroid drugs to control their disease. Among these individuals, the prevalence of sulfite sensitivity is about 8%, while it is about 1% in asthmatics who are not dependent on steroids (Taylor and Bush, 1986). 

Hypersensitivity to salicylates or nonsteroidal anti-inflammatory drugs (NSAIDs). Use extreme caution in patients with history of adverse reactions to salicylates. Cross-sensitivity may exist between aspirin and other NSAIDs that inhibit prostaglandin synthesis, and aspirin, and tartrazine. Aspirin cross-sensitivity does not appear to occur with sodium salicylate, salicylamide, or choline salicylate. Aspirin hypersensitivity is more prevalent in those with asthma, nasal polyposis, chronic urticaria. 

When it is assumed that the effectiveness of two therapies is equal, the effectiveness part of the cost-effectiveness ratio can be dropped from the analysis. In this situation, only the cost differences between the two therapies are examined. Usually this includes the cost of the drug, costs of administration, the treatment of side effects or adverse reactions and the incidence and prevalence of the condition. For example, Fenton et al. (1982) compared the costs of home versus hospital treatment of psychiatric patients when the outcomes of each were considered not to differ in any respect except that one requires a hospital stay and the other does not. The cost-minimization analysis simply looked at the differences in costs of the two treatments. The result is, not unexpectedly, that hospitalization was 64% more expensive than home-based treatment. 

The increasing prevalence of strains of P. falciparum that are resistant to chloroquine (CQ), a blood schizontocide which had been efficacious, safe, accessible and affordable, poses a serious problem for malaria control, predisposing Afiica to an unprecedented situation since the only affordable treatment options are rapidly losing therapeutic efficacy. Drug-resistant strains of P. falciparum are endemic in many areas of the world and the majority of conventional antimalarial drugs have been associated with treatment failure. These developments and the difficulty of creating efficient vaccines, coupled with adverse reactions to chemotherapy, underline the urgent need for novel, cheap, safe and... 

Cutaneous reactions are among the most prevalent adverse effects of therapeutic drugs. Ranging from relatively minor skin rashes to more serious toxic consequences such as SJS and TEN, these cutaneous effects can impose major limitations on clinical therapeutic use. Mechanisms of adverse cutaneous drug reactions may be immune mediated, photochemical, directly related to therapeutic activity, or idiosyncratic toxidties for which the mechanisms are poorly understood. 

Clinicians have only recently realized that chronic adverse effects of antiepileptic drugs, mainly those involving central nervous system, may be more disabling to the patient than the seizures themselves. Up to a few years ago, the historical belief that seizure frequency is the major determinant of health-related quality of life and that adverse reactions are merely a secondary end-point was the prevalent opinion. It has been shown that changes in seizure rate among patients with drug-resistant epilepsy are only modestly correlated with quality of life, while adverse reactions and depression are critical determinants of subjective health status [I "]. 

A retrospective review of 462,969 adult patients was carried out to assess the risk and pattern of cutaneous adverse reactions associated with the use of PPIs. Sixty-four patients with cutaneous adverse reactions were identified within the study population, and matched with 65 subjects, who did not experience adverse events while on therapy with PPIs. The overall prevalence of cutaneous reactions was 22.6 per 100,000 treated subjects, with specific values of 20, 16,15,10 and 3 per 100,000 for lansoprazole, pantoprazole, omeprazole, rabeprazole and esomeprazole, respectively. Most cutaneous reactions were attributed to omeprazole (n = 50 78.1%). The most frequent reaction was maculo-papular rash (43.8%), but other adverse events included cases of angioedema and/or urticaria, Stevens-Johnson syndrome and toxic epidermal necrolysis, erytiiema multiforme, eczematous drug eruption, urticarial vasculitis and fixed drug eruption. None of the patients experienced cross-reactions among individual PPIs [34 ]. 

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