In Canada—

Other commonly used names are Tryptophan

• Antidepressant therapy adjunct
• Antimanic

L-tryptophan ( L-TRIP-toe-fan) is used along with other medications to treat mental depression. Also, L-tryptophan is used along with lithium to treat bipolar disorder.

L-tryptophan is available in the following dosage forms:

Oral
• Capsules (Canada)
• Tablets (Canada)

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

• 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

Take with a low-protein, carbohydrate-rich meal or snack to prevent an upset stomach.

Dosing—

The dose of L-tryptophan will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of L-tryptophan. If your dose is different, do not change it unless your doctor tells you to do so.

The number of capsules or tablets that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are taking L-tryptophan.

• For oral dosage forms (capsules or tablets):
  • For mental depression:
    • Adults—8 to 12 grams per day, given in 3 to 4 equally divided doses
    • Children—Use and dose must be determined by your doctor.

Missed dose—

If you miss a dose of this medicine, it is not necessary to make up the missed dose. Skip the missed dose and continue with your next scheduled dose. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store the capsule or tablet form of this medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

It is important that your doctor check your progress at regular visits, to allow dosage adjustments and help reduce any side effects.

This medicine may cause some people to become drowsy, dizzy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert.

This medicine may cause dryness of the mouth. Using sugarless candy or gum, ice, or a saliva substitute may be helpful. Check with your physician or dentist if dry mouth continues for more than 2 weeks.

Avoid excessive exposure to ultraviolet light to reduce the chance of cataract formation.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Get emergency help immediately if any of the following symptoms of overdose occur

• Agitation;  confusion;  diarrhea;  fever;  overactive reflexes;  poor coordination;  restlessness;  shivering;  sweating;  talking or acting with excitement you cannot control;  trembling or shaking;  twitching;  vomiting 

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• Dizziness;  drowsiness ;  dry mouth;  headache;  loss of appetite;  nausea 

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.