Hypersensitivity reactions with antiretrovirals

The most common adverse effects associated with enfuvirtide therapy are local injection site reactions. Hypersensitivity reactions may rarely occur, are of varying severity, and may recur on rechallenge. Eosinophilia has also been noted. In one prospective clinical trial, an increased rate of bacterial pneumonia was noted in patients receiving enfuvirtide. No interactions have been identified that would require the alteration of the dosage of other antiretroviral drugs. 

The efficacy and safety of abacavir (NRTI) and efavirenz (NNRTI) plus background therapy have been retrospectively evaluated in 50 patients, who had previously been treated with highly active antiretroviral therapy (HAART) (4). There was some immunological benefit, albeit limited, in most of the patients. Adverse effects were not mentioned in detail, but the dropout rate during the first 4 weeks of treatment was high, owing to skin rashes and hypersensitivity reactions. 

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