Yarrow may interact with the following medications:

Medications to reduce stomach acid -- Because yarrow may increase the production of stomach acid, it can interfere with both over-the-counter and prescription drugs including:

• Cimetidine (Tagamet)
• Famotidine (Pepcid)
• Ranitidine (Zantac)
• Esomeprazole (Nexium)
• Omeprazole (Prilosec)
• Lansoprazole (Prevacid)

Medications for high blood pressure -- Yarrow may lower blood pressure slightly, and could make the effects of any prescription drugs you take to lower blood pressure stronger.

Drugs that cause sleepiness -- Because yarrow is a mild sedative, it can increase the effects of other drugs you take for anxiety or sleepiness. These include:

• Anticonvulsants such as phenytoin (Dilantin)
• Barbiturates
• Benzodiazepines such as alprazolam (Xanax) and diazepam (Valium)
• Drugs for insomnia, such as zolpidem (Ambien), zaleplon (Sonata), eszopiclone (Lunesta), ramelteon (Rozerem)