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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 7 of 7. This is the beginning of the thread.
Posted by kelv on December 23, 2006, at 12:47:16
Catechol-O-methyl transferase (COMT) (EC 2.1.1.6) is an enzyme first discovered by biochemist Julius Axelrod. COMT is the name given to the gene which codes for this enzyme. The O in the name stands for oxygen, not for ortho.
Catechol-O-methyl transferase is involved in the breakdown of the catecholamine neurotransmitters, dopamine, epinephrine and norepinephrine.
COMT inhibitors are found in green tea. Drinking green tea is, therefore, thought to provide a useful short-term boost to antidepressant medication by increasing the half life of extracellular noradrenaline and dopamine. [citation needed] Tea may also help reduce the risk of breast cancer.[2]-WIKIPEDIA.
Posted by blueberry1 on December 23, 2006, at 12:47:17
In reply to Stimulant @ AD booster-Green Tea?, posted by kelv on December 21, 2006, at 11:50:51
All I know is that one night I drank green tea for the first time and I nearly had a panic attack. I tried it because it was supposedly calming due to the theanine in it. I then tried theanine on its own and got very uncomfortably stimulated from it. Then I tried a little theanine mixed in some green tea and yikes I had a panic attack. Thankfully zypexa shut it down in a couple hours. But if green tea prolongs norepinephrine and dopamine then that makes sense to me.
Posted by kelv on December 23, 2006, at 12:47:18
In reply to Re: Stimulant @ AD booster-Green Tea?, posted by blueberry1 on December 21, 2006, at 18:54:44
> All I know is that one night I drank green tea for the first time and I nearly had a panic attack. I tried it because it was supposedly calming due to the theanine in it. I then tried theanine on its own and got very uncomfortably stimulated from it. Then I tried a little theanine mixed in some green tea and yikes I had a panic attack. Thankfully zypexa shut it down in a couple hours. But if green tea prolongs norepinephrine and dopamine then that makes sense to me.
Drinking strong Green Tea, does indeed seem to prolong, even bolster the effects of my ADD/HD medicine, as the science above suggests, to allow lower doses, more effective results. I have no experience with ADs and GT.
Posted by linkadge on December 23, 2006, at 12:47:18
In reply to Re: Green Tea-boosting Stimulants, ADs » blueberry1, posted by kelv on December 21, 2006, at 20:51:48
I have learned to avoid green tea with anything that inhibits the reuptake of norepinephrine.
I remember drinking green tea while on a TCA and feeling overstimulated.
Green tea citalopram was ok.
I think COMT inhibition MAO inhibition is ok. For instance quercetin is both a COMT and MAO inhibitor.
Linkadge
Posted by jimmygold70 on December 23, 2006, at 12:47:18
In reply to Stimulant @ AD booster-Green Tea?, posted by kelv on December 21, 2006, at 11:50:51
These are the interactions for Entacapone - a COMT inhibitor. Might they hold true for green tea? Exercise caution!
------------------------------
Entacapone
Comtan® PrintDrug Interactions
• Amoxapine
• Ampicillin
Antipsychotics
Anxiolytics, Sedatives, and Hypnotics
Barbiturates
• Buprenorphine
• Butorphanol
• Chloramphenicol
• Cholestyramine
• Dobutamine
• Dopamine
• Dronabinol, THC
• Droperidol
• Ephedra, Ma Huang
• Ephedrine
• Epinephrine
• Erythromycin
• Ethanol
• Furazolidone
• Isocarboxazid
• Isoetharine
• Isoniazid, INH
• Isoproterenol
• Linezolid
• Maprotiline
• Methyldopa
• Mirtazapine
• Nabilone
• Nalbuphine
• Nefazodone
• Norepinephrine
Opiate agonists
• Pentazocine
• Phenelzine
• Pramipexole
• Probenecid
• Procarbazine
• Rasagiline
• Rifampin
• Ropinirole
• Selegiline
• Tranylcypromine
• Trazodone
Tricyclic antidepressants
NOTE: Entacapone is highly protein bound. In vitro studies have shown no binding displacement between entacapone and other highly bound drugs, such as warfarin, salicylic acid, phenylbutazone, and diazepam.[5769] In vitro studies have shown that entacapone can inhibit the cytochrome P450 isoenzymes 1A2, 2A6, 2C6, 2C19, 2D6, 2E1 and 3A4, but only at very high entacapone concentrations (> 200 microM) that would not be seen during normal clinical usage.[5769]
It should be noted that entacapone may usually be taken concomitantly with the selective MAO-B inhibitors rasagiline and selegiline.[5769] For example, no drug-drug interactions have been shown between entacapone and selegiline in two multi-dose interaction studies.[5769] Stable doses of entacapone were used together with rasagiline in clinical trials.[9086] The practitioner should be alert to adverse effects and need for dosage titrations.
Patients should not receive entacapone in combination with non-selective monoamine oxidase inhibitors (MAOIs) such as isocarboxazid, phenelzine, or tranylcypromine.[5769] This includes agents with non-selective MAO inhibiting activity like furazolidone [5343], isoniazid, INH [4930], linezolid [5330] or procarbazine [5356]. Monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) are the two major enzymes involved in the metabolism of catecholamines. It is theoretically possible that the combination of entacapone and a non-selective MAOI would result in inhibition of the majority of pathways responsible for normal catecholamine metabolism. Typically, at least 14-days should elapse between the discontinuation of the non-selective MAOI and the use of entacapone to avoid potential interactions.
Drugs known to be metabolized by catechol-O-methyltransferase (COMT), such as bitolterol (beta-agonist), dobutamine [6302], dopamine [6393], ephedrine (or ephedra, ma huang) [6994] epinephrine [6234] [6995], isoetharine, isoproterenol [6995], methyldopa [5990], and norepinephrine [6235], regardless of the route of administration (including inhalation) should be administered cautiously in patients receiving entacapone.[5769] Concomitant use may result in increased heart rates, possibly arrhythmias, and excessive changes in blood pressure. When a single 400 mg dose of entacapone was given with intravenous isoproterenol and epinephrine the overall mean maximal changes in heart rate during infusion were about 50% and 80% higher than with placebo for isoproterenol and epinephrine, respectively. Ventricular tachycardia was noted in one healthy volunteer during an interaction study with epinephrine infusion and oral entacapone administration. Treatment with propranolol was required. A casual relationship to entacapone administration seems probable. A pharmacokinetic interaction of apomorphine with catechol-O-methyl transferase inhibitors (COMT inhibitors, e.g., tolcapone or entacapone) is unlikely since apomorphine appears not to be metabolized by COMT.[5392]
As entacapone is primarily excreted in the bile, caution should be exercised when drugs known to interfere with biliary excretion, glucuronidation, and intestinal beta-glucuronidation are given concurrently with entacapone.[5769] These agents include ampicillin, chloramphenicol, cholestyramine, erythromycin, probenecid, and rifampin.[5769]
Entacapone should be given cautiously with other agents that cause CNS depression due to the possibility of additive sedation.[5769] Agents that may cause additive sedation when given concurrently with entacapone include amoxapine, antipsychotics [5022], anxiolytics, sedatives, and hypnotics, opiate agonists, sedating H1-antagonists, barbiturates, buprenorphine, butorphanol, dronabinol, THC, droperidol, ethanol, maprotiline, mirtazapine, nabilone [9044], nalbuphine, nefazodone, pentazocine, pramipexole, ropinirole, trazodone, and tricyclic antidepressants. No pharmacokinetic interaction was noted when entacapone, without levodopa and carbidopa, and imipramine were given together in a single-dose study.
[ Interactions Last Revised: 6/14/2006 3:47:00 PM ]
--------------------------------------------------------------------------------References
4930. Nydrazid® Injection (isoniazid, INH)package insert. Princeton, NJ: Apothecon; 1997 Aug.
5022. Mellaril® (thioridazine) package insert. East Hanover, NJ: Novartis Pharmaceuticals Corporation; 2000 Jun.5330. Zyvox™ (linezolid) package insert. Kalamazoo, MI: Pharmacia & Upjohn Company; 2005 Feb.
5343. Furoxone® (furazolidone) package insert. Eatontown, NJ: Roberts Pharmaceutical Corporation; No date.5356. Matulane® (procarbazine) package insert.Gaithersburg, MD: sigma-tau Pharmaceuticals, Inc.; 2002 July.
5392. Apokyn™ and Apokyn™ Pen (apomorphine) injection package insert. Durham, NC:Mylan Bertek Pharmaceuticals Inc.; 2004 April.
5769. Comtan® (entacapone) package insert. East Hanover, NJ: Novartis Pharmaceuticals; 2000March.
5990. Aldomet® (methyldopa) package insert. West Point, PA: Merck & Co., Inc.;1998 Jul.6234. Epinephrine injection 1:1000 package insert. Shirley, NY: American Regent, Inc.; 2003 Jan.
6235. Norepinephrine package insert. Irvine, CA: Gensia Sicor Pharmaceuticals; 2002 Apr.
6302. Dobutamine Hydrochloride in 5% Dextrose Injection package insert. Deerfield, IL: Baxter Healthcare Corp.;2002 Jul.
6393. Intropin® (dopamine hydrochloride) injection package insert. Manati, Puerto Rico: Du Pont Pharmaceuticals;1991 Jan.
6994. Renfrew C, Dickson R, Schwab C. Severe hypertension following ephedrine administration in a patient receiving entacapone. Anesthesiology. 2000;93:1562.6995. Illi A, Sundberg S, Ojala-Karlsson P, et al. The effect of entacapone on the disposition and hemodynamic effects of intravenous isoproterenol and epinephrine. Clin Pharmacol Ther 1995;58:221—7.
9044. Cesamet™ (nabilone) package insert. Costa Mesa, CA: Valeant Pharmaceuticals International; 2006 May.9086. Goetz CG, Schwid SR, Eberly SW, et al. Safety of rasagiline in elderly patients with Parkinson disease. Neurology. 2006;66:1427—9.
Posted by linkadge on December 24, 2006, at 14:48:31
In reply to COMT inhibitors interactions, posted by jimmygold70 on December 22, 2006, at 3:36:40
I have combined green tea with Fo-Ti, (which is one of the strongest herbal MAO-B inhibitors)
I did notice and increased response, but I also noticed something kind of freaky.
When I was a kid I used to be "FREAKED OUT" by muppets and other non living puppets made to seem real. I tried the combination of fo-ti and green tea, and noticed I was scared by such things again.
It was like there was that similar loss of boundaries between what was real and what wasn't
Linkadge
Posted by Darwin on December 31, 2006, at 12:21:28
In reply to Stimulant @ AD booster-Green Tea?, posted by kelv on December 21, 2006, at 11:50:51
Recently, I increased my green tea intake to 4 tea bags a day (2 in the morning and 2 in the evening). After a couple of days, I developed a bad headache and my hands and feet felt cold. I believe this was due to COMT inhibition in combination with the drugs and supplements I am currently taking (amitriptyline, selegiline, and phenylethylamine). The cold hands and feet were probably due to blood constriction caused by increased peripheral norepinephrine.
When I stopped the green tea my symptoms vanished. Black tea, which is a much weaker COMT inhibitor, has never caused a problem. I find that I can still drink green tea as long as I limit my intake to 2 bags a day.
Darwin
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