• White willow bark relieves joint pain and inflammation but should be avoided by some individuals.Thinkstock Images/Comstock/Getty Images
  
  Imagine reaching for an herbal supplement instead of a bottle of aspirin, to relieve pain from conditions such as osteoarthritis, tendonitis, low-back pain or headaches. White willow bark has been used for these purposes for thousands of years. The alternative remedy contains salicin, a chemical component similar to acetylsalicylic acid, the active ingredient in aspirin. Like many over-the-counter and prescription medications, white willow bark is not appropriate for everyone and should be avoided in some cases.
  
  

Children Younger Than 16

• According to the University of Maryland Medical Center website, white willow bark may increase the risk of children younger than 16 to develop Reye's syndrome. Reye's syndrome is a rare, serious illness associated with children under the age of 16 who have been given aspirin. Reye's syndrome results in liver and brain swelling and symptoms such as continual vomiting, low blood sugar levels, seizures, sleepiness, aggression, confusion and loss of consciousness. Since the active component in white willow bark is related to aspirin, the use of white willow bark in children 16 or younger is not recommended.
  
  

Patients With Aspirin Allergies/Medical Conditions

• Due to the similarities between salicin and aspirin, patients who are allergic or have a hypersensitivity to aspirin should not take white willow bark or consume any products that contain white willow bark. According to the Mayo Clinic website, symptoms of an aspirin allergy include runny nose, coughing, shortness of breath, hives, itching on the skin and swelling of the face, including lips and tongue. Aspirin may also cause a serious asthma attack, particularly in patients who have sinus problems or asthma. The website Drugs additionally suggests avoiding white willow bark if you have diabetes, gout, liver problems, kidney conditions, impaired blood clotting and peptic ulcer disease.
  
  

Pregnant/Breastfeeding Mothers

• According to the University of Maryland Medical Center, aspirin and products containing aspirin are not recommended for use during pregnancy. Similarly, pregnant or breastfeeding mothers should avoid taking willow bark. The Drugs website points out that there is not enough information available regarding white willow bark's safety or effectiveness during pregnancy; it is best to err on the side of caution and avoid the product entirely.
  
  

Potential Drug Interactions

• Talk to your doctor before taking white willow bark to decrease the risk of experiencing a negative medication interaction. White willow bark may intensify the effects of anticoagulant medications such as warfarin, and increase your risk of uncontrolled bleeding. Avoid taking white willow bark if you take NSAIDs (nonsteroidal anti-inflammatory drugs) such as naproxen or ibuprofen; taking these medications together increases your risk of abdominal bleeding. White willow bark may increase your levels of certain drugs, including phenytoin and methotrexate -- increasing the risk of toxicity. Likewise, white willow bark decreases the effectiveness of medications such as diuretics and beta blockers.