What are the chances of having an antiretroviral allergy?

Reaction to HIV meds: http://en.wikipedia.org/wiki/management_of_hiv/aids#adverse_effects "allergy" is probably not the best word to use when describing reactions to medications. There are lots of side effects that are typical and common with medications for hiv. They are catalogued in the article above. Sometimes true allergies to these meds do occur. Best to google the individual medication to learn about its issues.