Kava Kava: Significant Interactions

ALCOHOL

Potentiation of CNS sedative effects has been reported in an animal study; however, one double-blind placebo-controlled study found no additive effects on CNS depression or safety related performance. Alternatively, a study of 10 subjects found that when alcohol and kava were combined, kava potentiated both the perceived and measured impairment compared to alcohol alone. Caution.

BARBITURATES

Additive effects are theoretically possible. Use with caution and monitor drug dosage. However, interaction may be beneficial under professional supervision.

BENZODIAZEPINES

Additive effects are theoretically possible. Use with caution and monitor drug dosage. However, interaction may be beneficial under professional supervision. The combination has been used successfully to ease symptoms of benzodiazepine withdrawal.

L-DOPA MEDICATION

Antagonistic effects are theoretically possible, thereby reducing the effectiveness of L-dopa. Avoid concurrent use unless under professional supervision.

METHADONE AND MORPHINE

Additive effects with increased CNS depression are theoretically possible, so use with caution, although interactions may be beneficial under professional supervision.

SUBSTRATES FOR CYP3A4

Although in vitro evidence suggests that kava inhibits CYP3A4, in vivo tests found no such effect. Until further research is conducted to determine whether the effect is clinically significant, interactions with drugs chiefly metabolised by CYP3A4 are speculative.

SUBSTRATES FOR CYP2E1

Inhibition of CYP2E1 has been demonstrated in vivo — serum levels of CYP2E1 substrates may become elevated — use caution.