Establishing an evidence base for the clinical management of catatonia is made difficult by the heterogeneous nature of the condition and the limited understanding of its pathophysiology. Benzodiazepines are a mainstay of treatment. The Cochrane review discussed identified only one eligible study (17 participants with catatonia who received either lorazepam or oxazepam), which found no difference on the single outcome measure (a 50% improvement on a visual analogue scale). This commentary discusses the findings in more detail, and considers what constitutes high-quality evidence for the acute treatment of catatonia, why there is such a paucity of randomised controlled trials (RCTs) on the topic and whether RCTs are both feasible and appropriate for the condition.

R,S-Oxazepam and R,S-temazepam can be separated in their enantiomers by means of a chiral AGP column. The corresponding R- and S-glucuronide conjugates can be separated on a normal reversed-phase C18 column. Man conjugates the S-enantiomer of oxazepam and temazepam both better than the R-enantiomer. The urinary recovery of the glucuronides following either R,S,-oxazepam or R,S-temazepam almost amounts to 100% of the dose administered.