A compound having the structure of formula (I) (R1 is as defined herein), including its stereoisomers and pharmaceutically acceptable salts and solvates. Such compounds are inhibitors of vesicular monoamine transporter 2 (VMAT2) and are useful, for example, in the treatment of hyperkinetic disorders. Also disclosed are compositions containing these compounds in combination with a pharmaceutically acceptable carrier, as well as methods relating to use in subjects in need thereof. In one embodiment, a pharmaceutical composition is provided comprising one or more compounds of structure (I) in combination with pharmaceutically acceptable additives and / or excipients.