Tramadol Hydrochloride/Acetaminophen

A 78‐year‐old female who had chronic kidney disease developed postherpetic neuralgia. She was prescribed several analgesics, but the pain was severe.

Shichimotsukokato was prescribed to this patient, and her pain was gradually relieved. During the course of treatment, the pain worsened when tramadol hydrochloride acetaminophen tablets were interrupted and improved upon their resuming their administration, suggesting an effect for the combination with shichimotsukokato. Her renal function did not worsen, but rather seemed to have improved.

Analgesics can be inappropriately used in patients with chronic kidney disease. For chronic kidney disease patients with postherpetic neuralgia, shichimotsukokato may have an effect on both pain and renal function and seems to be beneficial.

The objective was to study the relationship between crystal structure, particle deformation properties, and tablet-forming ability for the monoclinic form of paracetamol (PRA), 2 cocrystals and a salt crystal of PRA in addition to 2 coformers (oxalic acid and 4,4'-bipyridine). Thus, the structure-property-performance relationship was investigated. Analytical powder compression was used for determination of effective plasticity, as inferred from the Heckel yield pressure and the Frenning parameter, and the elastic deformation was determined from in-die tablet elastic recovery. The plasticity could not be linked to the crystal lattice structure as crystals containing zig-zag layers displayed similar plasticity as crystals containing slip planes. In addition, crystals containing slip planes displayed both high and low plasticity. The mechanical properties could not be linked to the tablet-forming ability as the tablet tensile strength, unexpectedly, displayed a tendency to reduce with increased plasticity. Furthermore, the elastic deformation could not explain the tablet-forming ability. It was concluded that no relationship between structure-property-performance for PRA and its cocrystals and salt could be established. Thus, it was indicated that to establish such a relationship, an improved knowledge of crystallographic structure and interparticle bonding during compaction is needed.