Before Using This Medicine

If you are taking this medicine without a prescription, carefully read and follow any precautions on the label. For L-tryptophan, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to L-tryptophan. Also tell your doctor and pharmacist if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—L-tryptophan has not been shown to cause birth defects or other problems in humans.

Breast-feeding— It is not known whether L-tryptophan passes into breast milk. However, L-tryptophan has not been reported to cause problems in nursing babies.

Children—Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of L-tryptophan in children with use in other age groups.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of L-tryptophan in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking L-tryptophan, it is especially important that your doctor and pharmacist know if you are taking any of the following:

• Lithium (e.g., Eskalith) or
• Monoamine oxidase (MAO) inhibitor activity (isocarboxazid [e.g., Marplan], phenelzine [e.g., Nardil], procarbazine [e.g., Matulane], selegiline [e.g., Eldepryl], tranylcypromine [e.g., Parnate])—Using these medicines with L-tryptophan may increase the chance of side effects

Other medical problems—The presence of other medical problems may affect the use of L-tryptophan. Make sure you tell your doctor if you have any other medical problems, especially:

• Achlohydria or malabsorption (digestion problems)—L-tryptophan may cause breathing problems in patients with certain types of digestion problems
• Bladder cancer—L-tryptophan may increase the risk of bladder cancer
• Cataracts—L-tryptophan may cause cataracts
• Diabetes mellitus (sugar diabetes)—L-tryptophan may cause diabetes in patients with a family history of diabetes