In a preliminary trial, an extract of periwinkle called vinpocetine was shown to produce minor improvements in short-term memory among people taking flunitrazepam, a benzodiazepine.¹ Further study is needed to determine if vinpocetine would be a helpful adjunct to use of benzodiazepines.

Kava (Piper methysticum) is an herb used to treat anxiety disorder. One individual who took a benzodiazepine (alprazolam) and kava together, along with two other medications (cimetidine and terazosin) was hospitalized in a lethargic and disoriented condition.2 Further research is needed to determine whether the combination of kava and benzodiazepines produces an adverse interaction. However, individuals should not take benzodiazepines and kava together unless supervised by a doctor.

In a study of healthy volunteers, administration of St. John's wort (Hypericum perforatum) along with alprazolam decreased blood levels of alprazolam, compared with the levels when alprazolam was taken by itself.3 Individuals taking alprazolam should not take St. John's wort without supervision by a doctor.