Idiosyncratic reaction resembling toxic epidermal necrolysis caused by chloroquine and maloprim

Diagnosis and management of the drug hypersensitivity reactions in Coronavirus disease 19: An EAACI Position Paper

Coronavirus disease 2019 (COVID-19), a respiratory tract infection caused by a novel human coronavirus, the severe acute respiratory syndrome coronavirus 2, leads to a wide spectrum of clinical manifestations ranging from asymptomatic cases to patients with mild and severe symptoms, with or without pneumonia. Given the huge influence caused by the overwhelming COVID-19 pandemic affecting over three million people worldwide, a wide spectrum of drugs is considered for the treatment in the concept of repurposing and off-label use. There is no knowledge about the diagnosis and clinical management of the drug hypersensitivity reactions that can potentially occur during the disease. This review brings together all the published information about the diagnosis and management of drug hypersensitivity reactions due to current and candidate off-label drugs and highlights relevant recommendations. Furthermore, it gathers all the dermatologic manifestations reported during the disease for guiding the clinicians to establish a better differential diagnosis of drug hypersensitivity reactions in the course of the disease.

How frequent are notified severe cutaneous adverse reactions to Fansidar?

An attempt was made to estimate the risk of severe cutaneous adverse reactions (SCARs) to Fansidar (sulfadoxine plus pyrimethamine). Cases were identified through a spontaneous reporting system. Persons exposed were estimated using sales data of 27 countries reporting one SCAR case for either Fansidar or a related product, Bactrim (cotrimoxazole; sulfamethoxazole plus trimethoprim). Between 1974 and 1989, 126 cases were notified for Fansidar: 87 cases of erythema multiforme or Stevens-Johnson syndrome, and 39 cases of toxic epidermic necrolysis. 86% of cases were reported in Europe or North America. In 116 cases with use known, prophylaxis was the reason in 103, and treatment in 13. Toxic epidermolysis and erythema multiforme/Stevens-Johnson syndrome had case fatalities of 36 (95% confidence intervals 21 to 53%) and 9% (4 to 18%), respectively. Fansidar users were estimated at 117 million, and the overall SCAR risk to be 1.1 (0.9 to 1.3) per million. For developing countries with mainly single dose use, the risk was estimated to 0.1 (0.0 to 0.1) per million. For Europe and North America with mainly prophylactic use, the risk was 10 (8 to 12) and 36 (23 to 48) per million, respectively. Prophylactic use had a 40 times higher risk than single dose therapeutic use. The aggregated risk peaked in 1984-1985, with global and North American SCAR frequencies of 3.4 (2.4 to 4.3) and 72 (41 to 102) per million, respectively. After 1985, North America reported only one further case despite continued use by an estimated 0.3 million persons.(ABSTRACT TRUNCATED AT 250 WORDS)

Ascertainment of risk of serious adverse reactions associated with chemoprophylactic antimalarial drugs

Serious adverse reactions during malaria chemoprophylaxis are reviewed. Three drugs considered to have caused serious reactions in recent years are pyrimethamine/sulfadoxine (Fansidar), pyrimethamine/dapsone (Maloprim) and amodiaquine. These reactions are principally independent of dose and cannot be determined during screening for optimal doses. However, host factors may precipitate dose-dependent reactions, some of which could be avoided with improvements in drug licensing. Since serious and life-threatening reactions are relatively rare (between 1:1000 and 1:20,000), Phase I to III trials cannot identify them. Reliance must therefore be placed on Phase IV post-marketing studies, including ongoing reviews of national registers, and specially tailored studies to identify the risk using prescription-event monitoring in high-risk populations. Occasionally, medical-record linkage, case-control and cohort studies may provide supportive data. Although large numbers of travellers must, of necessity, be exposed to a drug before relatively rare reactions are identified, the ascertainment of risk using post-marketing surveillance was prevented by the following five deficiencies: lack of awareness of early alerts, inadequate use of national registers, poor attention to epidemiological and statistical rigour, inadequate verification of denominators, and inadequacy of data records. Recommendations are given for minimizing such errors in the future.