If you are currently being treated with any of the following medications, you should not use either American skullcap or Chinese skullcap without first talking to your health care provider.

Sedatives -- Both American skullcap and Chinese skullcap 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 herbs with a sedating effect, such as valerian, kava, and catnip.

Drugs for Diabetes -- Chinese skullcap can lower blood sugar, and could make the effects of drugs taken for diabetes stronger, leading to the risk of hypoglycemia (low blood sugar).