Difference between oxymorphone and hydromorphone?

Semi synthetic : Oxymorphone is a semi synthetic form of morphine. Comes in immediate and extended release formulas and used for chronic pain. Hydromorphone is a deritive of morphine as well but works best in IV form. Oral formulations do exist but are not reliably effective due to how they are broken down in body. Both are narcotics and controlled substances that can cause respiratory depression, use caution.