The invention relates to a pharmaceutical composition comprising first particles and second particles, the first particles comprising at least one opioid or a pharmaceutically acceptable salt thereof, and the second particles comprising at least one opioid antagonist or a pharmaceutically acceptable salt thereof, wherein the first and second particles cannot be distinguished from one another by visually detectable and/or physical properties, wherein the release of the opioid antagonist occurs continuously over a period of 30 minutes to as much as 8 hours after oral administration, and a dosage form containing it for peroral administration. In addition, the invention relates to a pharmaceutical composition that comprises a particle with the opioid and with the opioid antagonist with the above-mentioned release characteristics.
