No idea if this response will be of any use but just in case: my OH had agonising pain in his back the other weekend with pressure on the nerves from either the cancer mets and/or an inflammation in the spine...Oramorph didn't help so we ended up calling the out-of-hours doctor who gave him an injection in the buttock of something that made a massive difference within 20 minutes and lasted for 12 hours. Don't know what it was but it did the trick. The next day he was put on slow release morphine 10mg twice a day and told to up the Oromorph to 2.5mg with up to 20mg over a 4 hour period if necessary, plus take Ibuprofen and Paracetemol in turn every two hours.
The next day he had radiotherapy to deal with the inflammation and was put on a high does of Dexamethodone plus continued to take the various painkillers.
Eight days later and all's calmed down on the pain front (not anywhere else but we are thankful for small mercies!).
Hope that's of some help! I do feel for you - 15/10 sounds unbearable.
Eleanor
x