Nutritional Supplement

L-Tryptophan

Also indexed as: Tryptophan

  • Negative Interactions

    18

    • L-Tryptophan

      Almotriptan

      Potential Negative Interaction

      Triptans work by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them with eletriptan could increase eletriptan-induced side effects. However, no interactions have yet been reported with eletriptan and 5-HTP or L-tryptophan.

    • L-Tryptophan

      Citalopram

      Potential Negative Interaction

      Citalopram increases serotonin activity in the brain. 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking either of these compounds with citalopram may increase citalopram-induced side effects. Dietary supplements of L-tryptophan (available only by prescription from special compounding pharmacists) taken with paroxetine (a drug that has similar actions as citalopram) caused headache, sweating, dizziness, agitation, restlessness, nausea, vomiting, and other symptoms.

      Some doctors have used small amounts of L-tryptophan in combination with SSRIs, to increase their effectiveness. However, because of the potential for side effects, 5-HTP and L-tryptophan should never be taken in combination with citalopram or other SSRIs, unless a doctor is closely monitoring the combination. Foods rich in L-tryptophan do not appear to interact with citalopram or other SSRIs.

      Citalopram
      L-Tryptophan
      ×
      1. Threlkeld DS, ed. Central Nervous System Drugs, Antidepressants, Selective Serotonin Reuptake Inhibitors. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, 1997.

    • L-Tryptophan

      Eletriptan

      Potential Negative Interaction

      Eletriptan works by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them with eletriptan could increase eletriptan-induced side effects. However, no interactions have yet been reported with eletriptan and 5-HTP or L-tryptophan.

    • L-Tryptophan

      Escitalopram

      Potential Negative Interaction

      Escitalopram increases serotonin activity in the brain. 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking either of these compounds with escitalopram may increase escitalopram-induced side effects. Dietary supplements of L-tryptophan (available only by prescription from special compounding pharmacists) taken with paroxetine (a drug that has similar actions as escitalopram) caused headache, sweating, dizziness, agitation, restlessness, nausea, vomiting, and other symptoms.

      Some doctors have used small amounts of L-tryptophan in combination with SSRIs, to increase their effectiveness. However, because of the potential for side effects, 5-HTP and L-tryptophan should never be taken in combination with escitalopram or other SSRIs, unless a doctor is closely monitoring the combination. Foods rich in L-tryptophan do not appear to interact with escitalopram or other SSRIs.

      Escitalopram
      L-Tryptophan
      ×
      1. Threlkeld DS, ed. Central Nervous System Drugs, Antidepressants, Selective Serotonin Reuptake Inhibitors. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, 1997.

    • L-Tryptophan

      Fluoxetine

      Potential Negative Interaction

      L-tryptophan is an amino acid found in protein-rich foods. Foods rich in L-tryptophan are not believed to cause any problems during fluoxetine use. However, dietary supplements of L-tryptophan taken during fluoxetine treatment have been reported to cause headache, sweating, dizziness, agitation, restlessness, nausea, vomiting, and other symptoms.

      Fluoxetine
      L-Tryptophan
      ×
      1. Threlkeld DS, ed. Central Nervous System Drugs, Antidepressants, Selective Serotonin Reuptake Inhibitors. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Apr 1997, 264r-4s.

    • L-Tryptophan

      Fluvoxamine

      Potential Negative Interaction

      Fluvoxamine works by increasing serotonin activity in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them with fluvoxamine may increase fluvoxamine-induced side effects. Until more is known, 5-HTP and L-tryptophan should not be taken with any SSRI drug, including fluvoxamine.

    • L-Tryptophan

      Frovatriptan

      Potential Negative Interaction

      Triptans work by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them at the same time as 5-HT1 agonists could increase unwanted side effects. However, at the time of this writing there are no known interactions with 5-HT1 agonists and 5-HTP or L-tryptophan.

      Frovatriptan
      L-Tryptophan
      ×
      1. Wolters Kluwer Health, Inc. Facts and Comparisons [online] 2007 [cited 2007 Feb]. Available from http://www.factsandcomparisons.com.

    • L-Tryptophan

      Naratriptan

      Potential Negative Interaction

      This interaction is based on this drug belonging to a drug class. While this drug may differ from the text and references below, drugs within this class work in a similar way and this interaction is applicable to drugs within the same class.

      Sumatriptan works by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them with sumatriptan could increase sumatriptan-induced side effects. However, no interactions have yet been reported with sumatriptan and 5-HTP or L-tryptophan.

    • L-Tryptophan

      Olanzapine-Fluoxetine

      Potential Negative Interaction

      This interaction is based on this drug belonging to a drug class. While this drug may differ from the text and references below, drugs within this class work in a similar way and this interaction is applicable to drugs within the same class.

      Triptans work by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them at the same time as 5-HT1 agonists could increase unwanted side effects. However, at the time of this writing there are no known interactions with 5-HT1 agonists and 5-HTP or L-tryptophan.

      Olanzapine-Fluoxetine
      L-Tryptophan
      ×
      1. Wolters Kluwer Health, Inc. Facts and Comparisons [online] 2007 [cited 2007 Feb]. Available from http://www.factsandcomparisons.com.

    • L-Tryptophan

      Paroxetine

      Potential Negative Interaction

      Paroxetine increases serotonin activity in the brain. 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking either of these compounds with paroxetine may increase paroxetine-induced side effects. Dietary supplements of L-tryptophan (available only by prescriptions from special compounding pharmacists) taken with paroxetine caused headache, sweating, dizziness, agitation, restlessness, nausea, vomiting, and other symptoms. Some doctors have used small amounts of L-tryptophan in combination with SSRIs, to increase the effectiveness of the latter. However, because of the potential for side effects, 5-HTP and L-tryptophan should never be taken in combination with paroxetine or other SSRIs, unless the combination is being closely monitored by a doctor. Foods rich in L-tryptophan do not appear to interact with paroxtine or other SSRIs.

      On the other hand, the combination of 45 mg DL-tryptophan (a synthetic variation of L-tryptophan) per pound of body weight (a relatively high dose) with zimelidine, a drug with a similar action to paroxetine, did not cause these side effects in another trial.

      Paroxetine
      L-Tryptophan
      ×
      1. Threlkeld DS, ed. Central Nervous System Drugs, Antidepressants, Selective Serotonin Reuptake Inhibitors. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Apr 1997, 264q-4r.
      2. Walinder J, Carlsson A, Persson R. 5-HT reuptake inhibitors plus tryptophan in endogenous depression. Acta Psych Scand Suppl 1981;290:179-90.

    • L-Tryptophan

      Paroxetine Mesylate

      Potential Negative Interaction

      This interaction is based on this drug belonging to a drug class. While this drug may differ from the text and references below, drugs within this class work in a similar way and this interaction is applicable to drugs within the same class.

      Sertraline increases serotonin activity in the brain. 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking either of these compounds with sertraline may increase sertraline-induced side effects.

      In one report, dietary supplements of L-tryptophan (available only by prescriptions from special compounding pharmacists) taken with paroxetine (a drug similar to sertraline) caused headache, sweating, dizziness, agitation, restlessness, nausea, vomiting, and other symptoms. On the other hand, the combination of 45 mg DL-tryptophan (a synthetic variation of L-tryptophan) per pound of body weight (a relatively high dose) with zimelidine, a drug with a similar action to sertraline, did not cause these side effects in another trial. Some doctors have used small amounts of L-tryptophan in combination with SSRIs, to increase the effectiveness of the latter. However, because of the potential for side effects, 5-HTP and L-tryptophan should never be taken in combination with sertraline or other SSRIs, unless the combination is being closely monitored by a doctor. Foods rich in L-tryptophan do not appear to interact with sertraline or other SSRIs.

      Paroxetine Mesylate
      L-Tryptophan
      ×
      1. Threlkeld DS, ed. Central Nervous System Drugs, Antidepressants, Selective Serotonin Reuptake Inhibitors. In Facts and Comparisons Drug Information. St. Louis, MO: Facts and Comparisons, Apr 1997, 264q-4r.
      2. Walinder J, Carlsson A, Persson R. 5-HT reuptake inhibitors plus tryptophan in endogenous depression. Acta Psych Scand Suppl 1981;290:179-90.

    • L-Tryptophan

      Rizatriptan

      Potential Negative Interaction

      Triptans work by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them at the same time as 5-HT1 agonists could increase unwanted side effects. However, at the time of this writing there are no known interactions with 5-HT1 agonists and 5-HTP or L-tryptophan.

      Rizatriptan
      L-Tryptophan
      ×
      1. Wolters Kluwer Health, Inc. Facts and Comparisons [online] 2007 [cited 2007 Feb]. Available from http://www.factsandcomparisons.com.

    • L-Tryptophan

      Sibutramine

      Potential Negative Interaction

      The amino acids L-tryptophan and 5-hydroxytryptophan (5-HTP) are occasionally used to treat mental depression. Taking sibutramine with L-tryptophan or 5-HTP might result in a rare, but serious group of symptoms known as “serotonin syndrome.” Symptoms associated with serotonin syndrome may include confusion, anxiety, muscle weakness, incoordination, and vomiting. Therefore, individuals taking sibutramine should avoid supplementing with L-tryptophan and 5-HTP.

      Sibutramine
      L-Tryptophan
      ×
      1. Sifton DW, et. Physicians' Desk Reference. Montvale, NJ: Medical Economics Company, Inc. 2000, 1509-13.

    • L-Tryptophan

      Sumatriptan Succinate

      Potential Negative Interaction

      This interaction is based on this drug belonging to a drug class. While this drug may differ from the text and references below, drugs within this class work in a similar way and this interaction is applicable to drugs within the same class.

      Sumatriptan works by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them with sumatriptan could increase sumatriptan-induced side effects. However, no interactions have yet been reported with sumatriptan and 5-HTP or L-tryptophan.

    • L-Tryptophan

      Tramadol

      Potential Negative Interaction

      Tramadol, which blocks serotonin reuptake in the brain, has been associated with two cases of serotonin syndrome. 5-HTP and L-tryptophan are converted to serotonin in the brain. While no interactions have yet been reported with tramadol and 5-HTP or L-tryptophan, taking 5-HTP or L-tryptophan with tramadol may increase the risk of tramadol-induced side effects, including serotonin syndrome.

      Tramadol
      L-Tryptophan
      ×
      1. Mason BJ, Blackburn KH. Possible serotonin syndrome associated with tramadol and sertraline coadministration. Ann Pharmacother 1997;31:175-7.
      2. Hernandez AF, Montero MN, Pla A, Villanueva E. Fatal moclobemide overdose or death caused by serotonin syndrome? J Forensic Sci 1995;40:128-30.

    • L-Tryptophan

      Venlafaxine

      Potential Negative Interaction

      Venlafaxine, a potent serotonin reuptake inhibitor, has been associated with several cases of serotonin syndrome. 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking them with venlafaxine may increase venlafaxine-induced side effects. While no interactions with venlafaxine and 5-HTP or L-tryptophan have been reported, until more is known, people taking venlafaxine are cautioned to avoid 5-HTP or L-tryptophan.

      Venlafaxine
      L-Tryptophan
      ×
      1. Brubacher JR, Hoffman RS, Lurin MJ. Serotonin syndrome from venlafaxine-tranylcypromine interaction. Vet Hum Toxicol 1996;38:358-61.
      2. Weiner LA, Smythe M, Cisek J. Serotonin syndrome secondary to phenelzine-venlafaxine interaction. Pharmacotherapy 1998;18:399-403.
      3. Bhatara VS, Magnus RD, Paul KL, Preskorn SH. Serotonin syndrome induced by venlafaxine and fluoxetine: a case study in polypharmacy and potential pharmacodynamic and pharmacokinetic mechanisms. Ann Pharmacother 1998;32:432-6.
      4. Diamond S, Pepper BJ, Diamond ML, et al. Serotonin syndrome induced by transitioning from phenelzine to venlafaxine: four patient reports. Neurology 1998;51:274-6.

    • L-Tryptophan

      Zolmitriptan

      Potential Negative Interaction

      Zolmitriptan works by stimulating serotonin receptors in the brain. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them with zolmitriptan could increase zolmitriptan-induced side effects. However, no interactions have yet been reported with zolmitriptan and 5-HTP or L-tryptophan.

    • L-Tryptophan

      Zolpidem

      Potential Negative Interaction

      Nine cases of zolpidem-induced hallucinations associated with serotonin reuptake inhibiting antidepressants have been reported, some lasting for several hours. 5-HTP (5-Hydroxytryptophan) and L-tryptophan are converted to serotonin in the brain, and taking them with zolpidem may increase zolpidem-induced hallucinations, though no interactions have yet been reported with zolpidem and 5-HTP or L-tryptophan.

      Zolpidem
      L-Tryptophan
      ×
      1. Elko CJ, Burgess JL, Robertson WO. Zolpidem-associated hallucinations and serotonin reuptake inhibition: a possible interaction. J Toxicol Clin Toxicol 1998;36:195-203.

  • Supportive Interactions

    15

    • L-Tryptophan

      Clozapine

      Replenish Depleted Nutrients

      Some people who take clozapine become mentally depressed after taking the drug for a few weeks. Studies have shown that clozapine can reduce blood levels of the amino acid L-tryptophan, which is often deficient in people with depression. More controlled research is needed to determine whether the interaction is significant and whether individuals taking clozapine might benefit from supplemental L-tryptophan or 5-hydroxytryptophan (5-HTP).

      Clozapine
      L-Tryptophan
      ×
      1. Meltzer HY. Clinical studies on the mechanism of action of clozapine: the dopamine-serotonin hypothesis of schizophrenia. Psychopharmacology 1989;99 Suppl:S18-27 (Berlin).

    • L-Tryptophan

      Diclofenac

      Replenish Depleted Nutrients

      Diclofenac causes complex changes to L-tryptophan levels in the blood, but the clinical implications of this are unknown. More research is needed to determine whether supplementation with L-tryptophan is a good idea for people taking diclofenac.

      Diclofenac
      L-Tryptophan
      ×
      1. Davies NM, Anderson KE. Clinical pharmacokinetics of diclofenac. Therapeutic insights and pitfalls. Clin Pharmacokinet 1997;33:184-213.

    • L-Tryptophan

      Allopurinol

      Support Medicine

      In a preliminary study, seven of eight individuals with severe mental depression showed improvement when they took L-tryptophan and allopurinol; of these seven, five experienced full remission. Controlled research is necessary to determine whether this combination might be more effective for severe depression than standard treatment.

      Allopurinol
      L-Tryptophan
      ×
      1. Stern SL, Mendels J. Drug combinations in the treatment of refractory depression: a review. J Clin Psychiatry 1981;42:368-73.

    • L-Tryptophan and Vitamin B3

      Amitriptyline

      Support Medicine

      Combination of 6 grams per day L-tryptophan and 1,500 mg per day niacinamide (a form of vitamin B3) with imipramine has shown to be more effective than imipramine alone for people with bipolar disorder. These levels did not improve the effects of imipramine in people with depression. Lower amounts (4 grams per day of L-tryptophan and 1,000 mg per day of niacinamide) did show some tendency to enhance the effect of imipramine.

      The importance of the amount of L-tryptophan was confirmed in other studies, suggesting that if too much L-tryptophan (6 grams per day) is used, it is not beneficial, while levels around 4 grams per day may make tricyclic antidepressants work better.

      Amitriptyline
      L-Tryptophan and Vitamin B3
      ×
      1. Chouinard G, Young SN, Annable L, Sourkes TL. Tryptophan-nicotinamide, imipramine and their combination in depression. Acta Psychiatr Scand 1979;59:395-414.
      2. Walinder J, Skott A, Carlsson A, et al. Potentiation of the antidepressant action of clomipramine by tryptophan. Arch Gen Psychiatry 1976;33:1384-9.
      3. Shaw DM, MacSweeney DA, Hewland R, Johnson AL. Tricyclic antidepressants and tryptophan in unipolar depression. Psychol Med 1975;5:276-8.

    • L-Tryptophan and Vitamin B3

      Amoxapine

      Support Medicine

      Combination of 6 grams per day L-tryptophan and 1,500 mg per day niacinamide (a form of vitamin B3) with imipramine has shown to be more effective than imipramine alone for people with bipolar disorder. These levels did not improve the effects of imipramine in people with depression. Lower amounts (4 grams per day of L-tryptophan and 1,000 mg per day of niacinamide) did show some tendency to enhance the effect of imipramine.

      The importance of the amount of L-tryptophan was confirmed in other studies, suggesting that if too much L-tryptophan (6 grams per day) is used, it is not beneficial, while levels around 4 grams per day may make tricyclic antidepressants work better.

      Amoxapine
      L-Tryptophan and Vitamin B3
      ×
      1. Chouinard G, Young SN, Annable L, Sourkes TL. Tryptophan-nicotinamide, imipramine and their combination in depression. Acta Psychiatr Scand 1979;59:395-414.
      2. Walinder J, Skott A, Carlsson A, et al. Potentiation of the antidepressant action of clomipramine by tryptophan. Arch Gen Psychiatry 1976;33:1384-9.
      3. Shaw DM, MacSweeney DA, Hewland R, Johnson AL. Tricyclic antidepressants and tryptophan in unipolar depression. Psychol Med 1975;5:276-8.

    • L-Tryptophan and Vitamin B3

      Benztropine

      Support Medicine

      Akathisia is an adverse reaction to anti-psychotic drugs, where a person has an uncontrollable desire to be in constant motion. One preliminary report suggested that 4,000 mg of L-tryptophan and 25 mg niacin per day taken with benztropine enhances the treatment of akathisia. Controlled studies are necessary to determine whether L-tryptophan and niacin supplements might benefit most people taking benztropine who experience adverse reactions to anti-psychotic drugs.

      Benztropine
      L-Tryptophan and Vitamin B3
      ×
      1. Kramer MS, DiJohnson C, Davis P, et al. L-tryptophan in neuroleptic-induced akathisia. Biol Psychiatry 1990;27:671-2.

    • L-Tryptophan and Vitamin B3

      Clomipramine

      Support Medicine

      Combination of 6 grams per day L-tryptophan and 1,500 mg per day niacinamide (a form of vitamin B3) with imipramine has shown to be more effective than imipramine alone for people with bipolar disorder. These levels did not improve the effects of imipramine in people with depression. Lower amounts (4 grams per day of L-tryptophan and 1,000 mg per day of niacinamide) did show some tendency to enhance the effect of imipramine.

      The importance of the amount of L-tryptophan was confirmed in other studies, suggesting that if too much L-tryptophan (6 grams per day) is used, it is not beneficial, while levels around 4 grams per day may make tricyclic antidepressants work better.

      Clomipramine
      L-Tryptophan and Vitamin B3
      ×
      1. Chouinard G, Young SN, Annable L, Sourkes TL. Tryptophan-nicotinamide, imipramine and their combination in depression. Acta Psychiatr Scand 1979;59:395-414.
      2. Walinder J, Skott A, Carlsson A, et al. Potentiation of the antidepressant action of clomipramine by tryptophan. Arch Gen Psychiatry 1976;33:1384-9.
      3. Shaw DM, MacSweeney DA, Hewland R, Johnson AL. Tricyclic antidepressants and tryptophan in unipolar depression. Psychol Med 1975;5:276-8.

    • L-Tryptophan

      Desipramine

      Support Medicine

      Combination of 6 grams per day L-tryptophan and 1,500 mg per day niacinamide (a form of vitamin B3) with imipramine has shown to be more effective than imipramine alone for people with bipolar disorder. These levels did not improve the effects of imipramine in people with depression. Lower amounts (4 grams per day of L-tryptophan and 1,000 mg per day of niacinamide) did show some tendency to enhance the effect of imipramine.

      The importance of the amount of L-tryptophan was confirmed in other studies, suggesting that if too much L-tryptophan (6 grams per day) is used, it is not beneficial, while levels around 4 grams per day may make tricyclic antidepressants work better.

      Desipramine
      L-Tryptophan
      ×
      1. Chouinard G, Young SN, Annable L, Sourkes TL. Tryptophan-nicotinamide, imipramine and their combination in depression. Acta Psychiatr Scand 1979;59:395-414.
      2. Walinder J, Skott A, Carlsson A, et al. Potentiation of the antidepressant action of clomipramine by tryptophan. Arch Gen Psychiatry 1976;33:1384-9.
      3. Shaw DM, MacSweeney DA, Hewland R, Johnson AL. Tricyclic antidepressants and tryptophan in unipolar depression. Psychol Med 1975;5:276-8.

    • L-Tryptophan and Vitamin B3

      Doxepin

      Support Medicine

      Combination of 6 grams per day L-tryptophan and 1,500 mg per day niacinamide (a form of vitamin B3) with imipramine has shown to be more effective than imipramine alone for people with bipolar disorder. These levels did not improve the effects of imipramine in people with depression. Lower amounts (4 grams per day of L-tryptophan and 1,000 mg per day of niacinamide) did show some tendency to enhance the effect of imipramine.

      The importance of the amount of L-tryptophan was confirmed in other studies, suggesting that if too much L-tryptophan (6 grams per day) is used, it is not beneficial, while levels around 4 grams per day may make tricyclic antidepressants work better.

      Doxepin
      L-Tryptophan and Vitamin B3
      ×
      1. Chouinard G, Young SN, Annable L, Sourkes TL. Tryptophan-nicotinamide, imipramine and their combination in depression. Acta Psychiatr Scand 1979;59:395-414.
      2. Walinder J, Skott A, Carlsson A, et al. Potentiation of the antidepressant action of clomipramine by tryptophan. Arch Gen Psychiatry 1976;33:1384-9.
      3. Shaw DM, MacSweeney DA, Hewland R, Johnson AL. Tricyclic antidepressants and tryptophan in unipolar depression. Psychol Med 1975;5:276-8.

    • L-Tryptophan and Vitamin B3

      Imipramine

      Support Medicine

      Combination of 6 grams per day L-tryptophan and 1,500 mg per day niacinamide (a form of vitamin B3) with imipramine has shown to be more effective than imipramine alone for people with bipolar disorder. These levels did not improve the effects of imipramine in people with depression. Lower amounts (4 grams per day of L-tryptophan and 1,000 mg per day of niacinamide) did show some tendency to enhance the effect of imipramine.

      The importance of the amount of L-tryptophan was confirmed in other studies, suggesting that if too much L-tryptophan (6 grams per day) is used, it is not beneficial, while levels around 4 grams per day may make tricyclic antidepressants work better.

      Imipramine
      L-Tryptophan and Vitamin B3
      ×
      1. Chouinard G, Young SN, Annable L, Sourkes TL. Tryptophan-nicotinamide, imipramine and their combination in depression. Acta Psychiatr Scand 1979;59:395-414.
      2. Walinder J, Skott A, Carlsson A, et al. Potentiation of the antidepressant action of clomipramine by tryptophan. Arch Gen Psychiatry 1976;33:1384-9.
      3. Shaw DM, MacSweeney DA, Hewland R, Johnson AL. Tricyclic antidepressants and tryptophan in unipolar depression. Psychol Med 1975;5:276-8.

    • L-Tryptophan

      Lithium

      Support Medicine

      A small double-blind study found that combining 2–4 grams three times per day of L-tryptophan with lithium significantly improved symptoms in people with bipolar disorder or a mild form of schizophrenia. L-tryptophan is only available from doctors. It should be taken several hours before or after meals.

      Lithium
      L-Tryptophan
      ×
      1. Brewerton TD, Reus VI. Lithium carbonate and L-tryptophan in the treatment of bipolar and schizoaffective disorders. Am J Psychiatry 1983;140:757-60.

    • L-Tryptophan and Vitamin B3

      Nortriptyline

      Support Medicine

      Combination of 6 grams per day L-tryptophan and 1,500 mg per day niacinamide (a form of vitamin B3) with imipramine has shown to be more effective than imipramine alone for people with bipolar disorder. These levels did not improve the effects of imipramine in people with depression. Lower amounts (4 grams per day of L-tryptophan and 1,000 mg per day of niacinamide) did show some tendency to enhance the effect of imipramine.

      The importance of the amount of L-tryptophan was confirmed in other studies, suggesting that if too much L-tryptophan (6 grams per day) is used, it is not beneficial, while levels around 4 grams per day may make tricyclic antidepressants work better.

      Nortriptyline
      L-Tryptophan and Vitamin B3
      ×
      1. Chouinard G, Young SN, Annable L, Sourkes TL. Tryptophan-nicotinamide, imipramine and their combination in depression. Acta Psychiatr Scand 1979;59:395-414.
      2. Walinder J, Skott A, Carlsson A, et al. Potentiation of the antidepressant action of clomipramine by tryptophan. Arch Gen Psychiatry 1976;33:1384-9.
      3. Shaw DM, MacSweeney DA, Hewland R, Johnson AL. Tricyclic antidepressants and tryptophan in unipolar depression. Psychol Med 1975;5:276-8.

    • L-Tryptophan and Vitamin B3

      Protriptyline

      Support Medicine

      Combination of 6 grams per day L-tryptophan and 1,500 mg per day niacinamide (a form of vitamin B3) with imipramine has shown to be more effective than imipramine alone for people with bipolar disorder. These levels did not improve the effects of imipramine in people with depression. Lower amounts (4 grams per day of L-tryptophan and 1,000 mg per day of niacinamide) did show some tendency to enhance the effect of imipramine.

      The importance of the amount of L-tryptophan was confirmed in other studies, suggesting that if too much L-tryptophan (6 grams per day) is used, it is not beneficial, while levels around 4 grams per day may make tricyclic antidepressants work better.

      Protriptyline
      L-Tryptophan and Vitamin B3
      ×
      1. Chouinard G, Young SN, Annable L, Sourkes TL. Tryptophan-nicotinamide, imipramine and their combination in depression. Acta Psychiatr Scand 1979;59:395-414.
      2. Walinder J, Skott A, Carlsson A, et al. Potentiation of the antidepressant action of clomipramine by tryptophan. Arch Gen Psychiatry 1976;33:1384-9.
      3. Shaw DM, MacSweeney DA, Hewland R, Johnson AL. Tricyclic antidepressants and tryptophan in unipolar depression. Psychol Med 1975;5:276-8.

    • L-Tryptophan

      Selegiline

      Support Medicine

      Both L-tryptophan and 5-HTP have been used to treat depression. One controlled study showed that taking selegiline at the same time as 5-HTP enhanced the antidepressant effect when compared with 5-HTP alone. Further research is needed to determine whether taking selegiline and 5-HTP together might result in unwanted side effects.

      Selegiline
      L-Tryptophan
      ×
      1. Mendlewicz J, Youdim MB. Antidepressant potentiation of 5-hydroxytryptophan by L-deprenil in affective illness. J Affect Disord 1980;2:137-46.

    • L-Tryptophan and Vitamin B3

      Trimipramine

      Support Medicine

      Combination of 6 grams per day L-tryptophan and 1,500 mg per day niacinamide (a form of vitamin B3) with imipramine has shown to be more effective than imipramine alone for people with bipolar disorder. These levels did not improve the effects of imipramine in people with depression. Lower amounts (4 grams per day of L-tryptophan and 1,000 mg per day of niacinamide) did show some tendency to enhance the effect of imipramine.

      The importance of the amount of L-tryptophan was confirmed in other studies, suggesting that if too much L-tryptophan (6 grams per day) is used, it is not beneficial, while levels around 4 grams per day may make tricyclic antidepressants work better.

      Trimipramine
      L-Tryptophan and Vitamin B3
      ×
      1. Chouinard G, Young SN, Annable L, Sourkes TL. Tryptophan-nicotinamide, imipramine and their combination in depression. Acta Psychiatr Scand 1979;59:395-414.
      2. Walinder J, Skott A, Carlsson A, et al. Potentiation of the antidepressant action of clomipramine by tryptophan. Arch Gen Psychiatry 1976;33:1384-9.
      3. Shaw DM, MacSweeney DA, Hewland R, Johnson AL. Tricyclic antidepressants and tryptophan in unipolar depression. Psychol Med 1975;5:276-8.

  • Explanation Required

    1

    • L-Tryptophan

      Clorazepate

      Needs Explanation

      Test tube studies show that L-tryptophan and clorazepate dipotassium interact in the blood in such a way that the actions of the drug may be enhanced when high amounts of L-tryptophan are ingested. Controlled research is needed to determine the significance of this interaction and to investigate possible interactions between clorazepate and 5-hydroxytryptophan, a supplement related to L-tryptophan.

      Clorazepate
      L-Tryptophan
      ×
      1. Coassolo P, Briand C, Bourdeaux M, Sari JC. Microcalorimetric method to determine competitive binding. Action of a psychotropic drug (dipotassium clorazepate) on L-tryptophan human serum albumin complex. Biochem Biophys Acta 1978;538:512-20.

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