Answer
Standard formulations release tramadol promptly. Prolonged-release formulations release it gradually and must be swallowed whole; they are not interchangeable without prescriber or pharmacist review.
Sources for this answer
- NHSNHS · NHS medicine guidance
- Zydol SR Tabs 100mg — Current selected SmPCemc · Summary of Product Characteristics
- Tramadol hydrochloride 50 mg prolonged-release capsules — Current selected SmPC