Dosing & Uses
Depression
8-12 g/d PO divided QID/TID
Lower dosage effective in combination with other antidepressants
Administration
Take with low-protein, carbohydrate-rich meals or snacks
Safety and efficacy not established
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (0)
Serious - Use Alternative (9)
- citalopram
citalopram and L-tryptophan both increase serotonin levels. Avoid or Use Alternate Drug. Combination may increase risk of serotonin syndrome or neuroleptic malignant syndrome-like reactions.
- desvenlafaxine
L-tryptophan and desvenlafaxine both increase serotonin levels. Avoid or Use Alternate Drug.
- isocarboxazid
isocarboxazid and L-tryptophan both increase serotonin levels. Avoid or Use Alternate Drug.
- linezolid
linezolid and L-tryptophan both increase serotonin levels. Avoid or Use Alternate Drug. Linezolid may increase serotonin as a result of MAO-A inhibition. If linezolid must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last linezolid dose or after 2 weeks of monitoring, whichever comes first.
- lorcaserin
L-tryptophan and lorcaserin both increase serotonin levels. Avoid or Use Alternate Drug.
- methylene blue
methylene blue and L-tryptophan both increase serotonin levels. Avoid or Use Alternate Drug. Methylene blue may increase serotonin as a result of MAO-A inhibition. If methylene blue must be administered, discontinue serotonergic drug immediately and monitor for CNS toxicity. Serotonergic therapy may be resumed 24 hours after last methylene blue dose or after 2 weeks of monitoring, whichever comes first.
- phenelzine
phenelzine and L-tryptophan both increase serotonin levels. Avoid or Use Alternate Drug.
- tranylcypromine
tranylcypromine and L-tryptophan both increase serotonin levels. Avoid or Use Alternate Drug.
- vilazodone
L-tryptophan, vilazodone. Either increases toxicity of the other by serotonin levels. Avoid or Use Alternate Drug. Concomitant use is not recommended.
Monitor Closely (54)
- 5-HTP
5-HTP and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- almotriptan
almotriptan and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- amitriptyline
amitriptyline and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- amoxapine
amoxapine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- buspirone
buspirone and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- clomipramine
clomipramine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- cocaine topical
cocaine topical and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- desipramine
desipramine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- dexfenfluramine
dexfenfluramine and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- dextroamphetamine
dextroamphetamine and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- dextroamphetamine transdermal
L-tryptophan, dextroamphetamine transdermal. Either increases effects of the other by serotonin levels. Modify Therapy/Monitor Closely. Initiate with lower doses and monitor for signs and symptoms of serotonin syndrome, particularly during initiation or dosage increase. If serotonin syndrome occurs, discontinue dextroamphetamine transdermal and concomitant serotonergic drug(s).
- dextromethorphan
dextromethorphan and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- dihydroergotamine
dihydroergotamine and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- dihydroergotamine intranasal
dihydroergotamine intranasal and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- doxepin
doxepin and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- duloxetine
duloxetine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- eletriptan
eletriptan and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- ergotamine
ergotamine and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- escitalopram
escitalopram and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- fenfluramine
fenfluramine and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- fluoxetine
fluoxetine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- fluvoxamine
fluvoxamine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- frovatriptan
frovatriptan and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- imipramine
imipramine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- isoniazid
isoniazid and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- levomilnacipran
levomilnacipran and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- lithium
L-tryptophan and lithium both increase serotonin levels. Use Caution/Monitor.
- lofepramine
lofepramine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- lsd
L-tryptophan and lsd both increase serotonin levels. Use Caution/Monitor.
- maprotiline
maprotiline and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- meperidine
L-tryptophan and meperidine both increase serotonin levels. Modify Therapy/Monitor Closely.
- milnacipran
milnacipran and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- mirtazapine
L-tryptophan and mirtazapine both increase serotonin levels. Use Caution/Monitor.
- morphine
L-tryptophan and morphine both increase serotonin levels. Use Caution/Monitor.
- naratriptan
naratriptan and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- nefazodone
nefazodone and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- nortriptyline
nortriptyline and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- paroxetine
paroxetine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- pentazocine
L-tryptophan and pentazocine both increase serotonin levels. Use Caution/Monitor.
- protriptyline
protriptyline and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- rasagiline
rasagiline and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- rizatriptan
rizatriptan and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- SAMe
L-tryptophan and SAMe both increase serotonin levels. Use Caution/Monitor.
- selegiline
selegiline and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- selegiline transdermal
selegiline transdermal and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- sertraline
sertraline and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- St John's Wort
L-tryptophan and St John's Wort both increase serotonin levels. Modify Therapy/Monitor Closely.
- sumatriptan
sumatriptan and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- sumatriptan intranasal
sumatriptan intranasal and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
- tramadol
L-tryptophan and tramadol both increase serotonin levels. Use Caution/Monitor.
- trazodone
trazodone and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- trimipramine
trimipramine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- venlafaxine
venlafaxine and L-tryptophan both increase serotonin levels. Modify Therapy/Monitor Closely.
- zolmitriptan
zolmitriptan and L-tryptophan both increase serotonin levels. Use Caution/Monitor.
Minor (0)
Adverse Effects
Frequency Not Defined
Anorexia
Dizziness
Dry mouth
Headache
Nausea
Sexual disinhibition
Warnings
Contraindications
Hypersensivity
Cautions
Bladder cancer
Diabetes mellitus
Achlorhydria/malabsorption
Cataract formation
Some bipolar pts are acutely sensitive & would not tolerate dosage >1-2 g/d
Clinical worsening & suicide ideation may occur despite medication
Pregnancy & Lactation
Pregnancy Category: C
Lactation: avoid during breastfeeding
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Metabolism: Converted to nicotinic acid & serotonin as well as incorporated into proteins
Excretion: N/A
Mechanism of Action
Incr serotonin synthesis
