A compound comprising or a pharmaceutically acceptable salt or a prodrug thereof, having the groups described in detail herein is disclosed. Also disclosed herein are compounds comprising or derivatives thereof, or pharmaceutically acceptable salts, tetrazoles, or prodrugs of compounds of the structure or derivatives thereof, said derivatives being described in detail herein. Also disclosed herein are methods of treating diseases or conditions, including glaucoma and elevated intraocular pressure. Compositions and methods of manufacturing medicaments related thereto are also disclosed.