L-tryptophan (Herb/Suppl)

Brand and Other Names:tryptophan
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Dosing & Uses

AdultPediatric

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

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Interactions

Interaction Checker

and L-tryptophan

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    Contraindicated

      Serious - Use Alternative

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            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 (53)

              • 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

                cocaine 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.

              • 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)

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                Adverse Effects

                Frequency Not Defined

                Anorexia

                Dizziness

                Dry mouth

                Headache

                Nausea

                Sexual disinhibition

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                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

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                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.

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                Pharmacology

                Metabolism: Converted to nicotinic acid & serotonin as well as incorporated into proteins

                Excretion: N/A

                Mechanism of Action

                Incr serotonin synthesis

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                Images

                No images available for this drug.
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                Patient Handout

                A Patient Handout is not currently available for this monograph.
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                Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.