Doses and formulations
The maximum licensed dose of each of the different analgesic drugs should be used. Morphine IR preparations take about 20 minutes for their analgesic effect to become apparent. Once the patient is stabilised on a 24-hour morphine dose, doses should be administered 12 hourly using an MR preparation. Some MR formulations can take up to two hours to have an analgesic effect and should NOT be used for breakthrough pain (prn use). Dispensing labels should specify dosing as 'every 12 hours' and not 'twice a day' for MR products.
