The present invention decreases the potential for abuse of opioids, particularly hydrocodone, by covalent modification. The invention provides methods of delivering hydrocodone as conjugates that release the hydrocodone following oral administration while being resistant to abuse by circuitous routes such as intravenous ("shooting") injection and intranasal administration ("snorting"). Further, hydrocodone compositions of the invention are resistant to oral abuse as well, since release of the hydrocodone at suprapharmacological doses reaches saturation.