If you are currently being treated with any of the following medications, you should not use valerian without talking to your health-care provider.

Sedatives -- Valerian can increase the effect of drugs that have a sedating effect, including

• Anticonvulsants such as phenytoin (Dilantin) and valproic acid (Depakote)
• Barbiturates
• Benzodiazepines such as alprazolam (Xanax) and diazepam (Valium)
• Drugs to treat insomnia, such as zolpidem (Ambien), zaleplon (Sonata), eszopiclone (Lunesta), and ramelteon (Rozerem)
• Tricyclic antidepressants such as amitriptyline (Elavil)
• Alcohol

The same is true of other herbs with a sedating effect, such as chamomile, lemon balm, and catnip.

Other drugs -- Because valerian is broken down by certain liver enzymes, it may interact with other drugs that are broken down by the same enzymes. Those drugs may include:

• Antihistamines
• Statins (drugs taken to lower cholesterol)
• Some antifungal drugs

Anesthesia -- Valerian may increase the effects of anesthesia and, thus, it is important to discuss the use of valerian with your doctors (particularly the surgeon and anesthesiologist) well in advance of your planned operation. The doctors may advise you on how to taper use of valerian prior to the surgery. Or, they may allow you to use valerian up to the time of surgery, making any necessary adjustments to the anesthesia.