L-tryptophan
General
Complementary/Alternative Medicine: This monograph describes a natural or herbal product that is not subject to FDA guidelines for medicines. Patients and clinicians are advised to read package labels carefully to ensure safe and efficacious use.
Pronunciation:
el trip-tuh-fan
Trade Name(s)
- tryptophan
Ther. Class.
mood stabilizers
smoking deterrents
Common Uses
- Premenstrual dysphoric disorder (PMDD)
- Depression.
- Smoking cessation.
- Insomnia.
Action
L-tryptophan is an essential amino acid that is converted by the body to 5–hydroxytryptophan (5–HTP) and then to serotonin. Both L-tryptophan and 5–HTP cross the blood-brain barrier and have sedative effects. Depletion of endogenous tryptophan can cause a relapse in depression symptoms.
Therapeutic Effect(s):
- Improved symptoms of depression.
- Improved sleep.
Pharmacokinetics
Absorption: Unknown
Distribution: Unknown
Metabolism and Excretion: Unknown
Half-life: Unknown
TIME/ACTION PROFILE
ONSET | PEAK | DURATION | |
---|---|---|---|
PO | unknown | unknown | unknown |
Contraindication/Precautions
Contraindicated in:
- Hypersensitivity.
- Pregnancy and lactation.
Use Cautiously in:
- Eosinophilia.
- Kidney disease.
- Liver disease.
Adverse Reactions/Side Effects
EENT: visual blurring
GI: abdominal pain, dry mouth, heartburn, nausea
Hemat: eosinophilia-myalgia syndrome
Neuro: ataxia, drowsiness, headache, lightheadedness
* CAPITALS indicate life-threatening.
Underline indicate most frequent.
Interactions
Natural Drug Interaction
- Increased risk of serotonergic effects and serotonin syndrome with SSRIs, dextromethorphan, meperidine, tricyclic antidepressants, monoamine oxidase inhibitors, and tramadol.
- Increased sedation with CNS depressants.
Natural-Natural:
- Additive sedation with herbs or supplements that have sedative properties such as kava St. John's wort valerian 5–HTP and others.
- Increased risk of serotonin syndrome with St. John's wort. .
Route/Dosage
PO (Adults): Insomnia: 1 gram 20 minutes before bedtime; Depression: 300 mg/day; Prementrual syndrome: 6 grams/day; Smoking cessation: 50 mg/kg/day.
Availability
Capsules:
Tablets: 500 mg
Assessment
- Assess sleep patterns prior to and periodically during therapy.
- Monitor for signs and symptoms of esosinophilia-myalgia sydrome (severe myalgia, arthralgia, intense eosinophilia) Less common symptoms include respiratory prodrome (cough, dyspnea, pulmonary infiltrates), limb edema, scleroderma, mononeuritis, evanescent skin rash, mild LFT elevations, and leukocytosis. If these symptoms occur, discontinue l-tryptophan.
Implementation
- PO Administer without regard to food.
Patient/Family Teaching
- Instruct patient to take as directed; do not take more than directed.
- Advise patient to notify health care professional of symptoms of esosinophilia-myalgia sydrome occur.
- Advise female patient to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
Evaluation/Desired Outcomes
Improvement in insomnia and premenstrual disorder.