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Dangerous Combos FAQ


Nov 30, 2001
Atlanta, Ga
OK, I'm going to need everyone's help on this. We are putting together a FAQ listing every known dangerous drug combo. I need everyone (with time) to post the bad drug mixes that they are aware of with as much supporting evidence as possible. If you are going to post a dangerous/deadly combo, please include any fatality info, how to avoid the combo, and what to do if you've mixed two drugs that don't interact well.

Here is an example to get us started, I'm not including sources as I don't have time to look up my references.

MDMA inhibits the body's ability to regulate it's temperature, often overheating the user. DXM inhibits sweating and when combined with MDMA can induce hyperthermia.

Also, DXM and MDMA are broken down by the same enzyme in the liver. When both drugs are taken, the enzyme can't break them both down and liver damage may occur.

Combining these drugs may also result in a potentially fatal condition called Serotonin Syndrome. Symptoms may include high body temperature, increased heart rate and seizure.

Ways to avoid this combo:
Don't roll if you have been using cold medicines with DXM in them. Don't mix brands of pills that haven't been EZ-Tested.
If you've taken this combo, stay cool. If you are in a rave or party, go to an outside chill area. Drink enough water to stay hydrated, but no more than 2 liters per hour.

[This message has been edited by Griff (edited 15 February 2001).]
[This message has been edited by Kyk (edited 17 March 2001).]

[Edit: fixed vB coding in all posts after upgrade, deleted some redundant/irrelevant posts - Orlando]
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Neural Shock

Nov 25, 1999
The FAQ at http://www.erowid.org/chemicals/dxm/faq/dxm_faq.shtml confirms the above. Also on the subject of DXM, do not mix DXM with:
  • Antidepressants of any kind. MAOIs (monoamine oxidase inhibitors) are the worst; DXM + a MAOI will kill you. DXM with other antidepressants can cause serotonin syndrome, an unpleasant and occasionally fatal condition.
  • Diet drugs like phentermine, fenfluramine (Redux), or phen-fen. Again, a risk of serotonin syndrome.
  • Non-drowsy antihistamines (allergy medicines) like Allegra, Seldane, or Hisminal.

Also mentioned in http://www.erowid.org/chemicals/dxm/faq/dxm_mixing.shtml#toc.13 are the contraindications:
  • DXM & barbiturates
  • DXM & moderate or more benzodiazpeines
  • DXM & amphetamines - high blood pressure
  • DXM & opiates - risk of respiratory failure
  • DXM & yohimbine or any other alpha-2 adrenergic antagonist - Olney's Lesions

[This message has been edited by Griff (edited 18 March 2001).]

[Edit: the erowid FAQ linked to was originally hosted on Frognet. However, Frognet has crashed, and looks like it will be down permanently. I've therefore edited the original links to point to the erowid versions - Simon]
[ 21 February 2003: Message edited by: Simon ]
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Neural Shock

Nov 25, 1999
Drugs to avoid when taking MAOIs, and two weeks after stopping MAOIs are:
  • All SSRIs (prozac, zoloft, and several other anti-depressants)
    SSRIs block the reuptake of serotonin in the brain. Because MAOIs inhibit the breakdown of serotonin, the combination of MAOIs and SSRIs can lead to dangerously high levels of serotonin in the brain (serotonin syndrome). Symptoms of serotonin syndrome include nausea, vomiting, blackouts, memory loss, increased blood pressure and increased heart rate.
  • Demerol
  • Cold preparations (tablets, capsules, or liquids such as Comtrex)
  • Cough medications containing decongestants or Demerol (Plain Robitussin is OK)
  • Sinus medications
  • Nose drops or nasal sprays
  • Nasal decongestants
  • Hay fever medications
  • Diet pills
  • Amphetamines --- speed
  • MDMA --- Ecstasy
  • MDE, MDA, and other "MD" compounds
  • Cocaine --- crack
This is sourced from Erowid

Also avoid DXM at recreational doses, as mentioned in the above reply.

Reversible MAOIs, such as Syrian Rue will potentiate LSAs, Psilocybin/Psilocin, DMT, Mescaline, various other phenethylamines & tryptamines. It's possible to overdose by going overboard with MAOI potentiation.

Finally, there are foods to be avoided with MAOIs, detailed at Erowid

[Edit: Fixed broken links - Simon]
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Neural Shock

Nov 25, 1999
Do not take GHB if you are taking:
  • benzodiazepines ("minor tranquillisers" such as Valium and Xanax)
  • phenothiazines ("major tranquillisers" like Thorazine and Stellazine)
  • various painkillers (barbiturates and opiates)
  • alcohol
  • anticonvulsants (Dilantin and phenobarbital)
  • many over-the-counter allergy and sleep remedies
  • any other CNS depressants
The absolute minimum time between taking GHB and taking alcohol is four hours, and you should make it six-eight hours if you are really drunk
. GHB's effects last maximum 3 hours unless you boost of course.

Also, do not take GHB if you suffer from any of the following conditions:
  • severe illness of any kind
  • epilepsy
  • convulsions
  • bradycardia or slowed heart-beat
  • Cushing's syndrome
  • severe cardiovascular disease
  • severe hypertension.
I got this info from a supplier, so I can't post the link
. I'll find other links if I can. Anyone with any more detail on the above should post it. I want to find more detail on the over-the-counter allergy and sleep-remedy bits.

[This message has been edited by Neural_Shock (edited 15 February 2001).]
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Feb 14, 2001
DXM inhibits sweating
The DXM faq section 6.1.5 states:
Diaphoresis (sweating)
Category: Frequent
Many DXM users note sweating both while on DXM and for several hours after coming down. Some have noted a peculiar odor to the sweat, which may be metabolites of DXM or may simply be a consequence of enhanced sense of smell. In any case, just drink lots of water and you should be fine.
I can also tell you this from first hand experience. I also doubt that it inhibits sweating while combined mdma. The DXM faq states that one of the symptoms of seretonin syndrome is sweating.

I just wanted to bring this to your attention, becuase some posters on usenet weren't too happy about Dancesafe putting out this bogus info. I believe Dancesafe have corrected this.
MDMA and DXM isn't a safe combo, but it's due to the other two factors stated in the original post.

I just discovered this board last week it seems like a great place with alot of cool people.
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Sep 16, 2000
Alcohol + anything, including itself.

70% of emergency room visits have alcohol involved. And most overdoses of drugs include alcohol.
MOST drugs (except GHB) have a very high safety margin, if ingested alone. My advice: stay away from combos.
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Nov 30, 1999
Milwaukee, WI, USA
Does anyone know of possible interactions with SSRE's such as Tianeptine(Stablon)? Also since the half life of Tianeptine is only 2.5 hours does that mean it wouldn't cause problems after that?


Bluelight Crew
Dec 6, 1999
Central Nervous System [CNS] Depressants
Central nervous system [CNS] depressants are drugs that slow down brain activity. CNS depressants include a wide range of drugs such as alcohol, barbiturates (Amytal, Nembutal, Seconal), benzodiazepines (Ativan, Halcion, Librium, Valium, Xanax), chloral hydrate, GHB, GBL, methaqualone (Quaaludes), buspirone (Buspar), and zolpidem (Ambien). CNS depressants can cause confusion and dizziness, and impair judgment, memory, intellectual performance, and motor coordination, especially when taken in excess and combined with one another. When mixed together, CNS depressants amplify each other's effects, which can cause severely reduced heart rate and even death. Overdoses of depressants produce effects that are the same as alcohol overdoses. The person becomes extremely drowsy and passes out. Their heartbeat slows and respiration will become shallow. Their skin may feel cold and clammy, and death may result from respiratory failure. CNS depressants are also dangerous when combined with opiates and opioids (like codeine, hydrocodone, oxycodone, and heroin).

Opiates and Opioids
This is a class of drugs that includes opium, heroin, morphine (MS Contin), codeine (Tylenol 2, Tylenol 3, Tylenol 4), hydromorphone (Dilaudid), oxycodone (Percodan, Percocet, and Oxycontin), meperidine (Demerol), hydrocodone (Vicodin, Norco, Lortab), propxyphene (Darvocet and Darvon), fentanyl (Duragesic and Actiq), and others. Like alcohol, opiates are dangerous when used in combination with drugs that suppress breathing. These include alcohol, barbiturates, benzodiazepines (Xanax, Valium, Ativan), CNS depressants (see above) and GHB. Combining opiates with other drugs that make you sleepy can basically lead the user into a sleep from which they will never wake up. It should be noted that opiate overdose is easily treatable and can be counteracted with Narcan available at your local emergency room.

This is a class of drugs that includes LSD, PCP, ketamine, mushrooms, mescaline, and Ecstasy. The most dangerous combination is the combination of PCP-like drugs with alcohol or other sedatives. This combination can kill you. Taking atropine-like drugs with anything that stimulates the cardiovascular system or raises the body temperature (like Ecstasy) can lead to dangerous disturbances of heart rhythms or increased body temperature. Hallucinogens with amphetamine-like actions (like mescaline) can be dangerous when taken in combination with other stimulants. This goes for Ecstasy (MDMA) also. MDMA, which has stimulant properties, may cause a user's heart rate to rise to dangerous levels when used in combination with other stimulants, like cocaine or methamphetamine (also see Stimulants below). Reactions may vary from person to person. As always, err on the side of caution.

As noted, using ketamine and alcohol is a dangerous combination. At lower levels, nausea and sickness will result. At higher levels serious health problems can occur. Ketamine, by itself, is valuable in a medical setting since it slows breathing at a lower rate than other anaesthetics. But combining ketamine with another CNS depressant, including GHB, can slow down breathing to a dangerously low or even fatal level (see CNS Depressant section). PCP (phencyclidine), like ketamine, is also an NMDA antagonist. As such, combinations with ketamine, alcohol, and other CNS depressants can also lead to negative health consequences.

Monoamine oxidase inhibitors (MAOIs) can cause a dangerous or lethal increase in heart pressure when combined with Ecstasy. Nardil (phenelzine), Parnate (tranylcypromine), pargyline, Marplan (isocarboxazid), Eldepryl (l-deprenyl), and Aurorix / Manerix (moclobemide), Ayahuasca also contains MAOIs (harmine and harmaline). Combining MDMA and MAOIs has been pushed by some, usually the uninformed, as means for increasing Ecstasy's effects. However, this is an extremely dangerous and potentially lethal combination.

It is dangerous to combine anything with alcohol that makes you sleepy (see CNS section). This includes opiates/opiods (heroin, morphine, Demerol, Percocet, Oxycontin), barbiturates, benzodiazepines (Xanax, Valium, Ativan) and GHB. It should also be noted that a large percentage of deaths and hospitalizations associated with Ecstasy have usually involved a combination with alcohol.

Possible dangerous combinations include a mix of marijuana with heart or blood pressure medication or with drugs that supress the function of the immune system. One recent study shows that the combination of marijuana with cocaine can lead to very dangerous effects on the heart.

This is a class of drugs that includes cocaine, methamphetamine (Desoxsyn), amphetamine (Adderall), MDMA (ecstasy -- which has hallucinogen and stimulant characteristics), dextroamphetamine (Dexedrine), methylphenidate (Ritalin), and dexmethylphenidate (Focalin). Stimulants can be dangerous when taken in combination with over-the-counter cold remedies that contain decogestants because the combined effect of the two can raise blood pressure to a dangerous level. Stimulants can also be dangerous when taken in combination with MAOIs. Cocaine is dangerous in combination with anything that makes people more sensitive to seizures, such as the prescription medication buspirone or extremly high levels of xanithines, like caffeine or theophylline. Stimulants are also dangerous when taken in combination with one another. Negative effects include heart attack, stroke, and death. People with a history of hypertension or other heart problems are especially susceptible problems associated stimulant and stimulant combinations.

This is a class of drugs that is intended for the relief of short-term anxiety. Alprazolam (Xanax), bromazepam (Lexotan), clobazam (Frisium), clonazepam (Klonopin), diazepam (Valium), lorazepam (Ativan), prazeman (Centrex), oxazepam (Serenid), flunitrazepam (Rophynol), temazepam (Euhypnos), and Triazolam (Halcion) are all benzodiazepines. While these drugs are not particularly toxic by themselves, at certain doses, amnesia-like side effects result in reduced inhibition, impaired judgment, poor coordination, and slower reaction time. All of these things can lead to unsafe behavior. When combined with other CNS depressants (see above), like alcohol, and/or opiates, benzodiazepines can lead to shallow breathing, respiratory failure, and even death.

Methadone magnifies the effects of alcohol and other central nervous system [CNS] depressants, such as antihistamines, cold medicines, sedatives, tranquilizers, other prescription and over-the-counter (OTC) pain medications, barbiturates, seizure medications, muscle relaxants, other opiates, and certain anesthetics including some dental anesthetics. Some dentists use a drug called Stadol (butorphanol artrate) which is a narcotic agonist/antagonist that reportedly will send a methadone user into acute withdrawl. Opioid partial agonist and agonist/antagonist drugs such as Buprenex, Talwin, Stadol, and Nubaine should never be used in the methadone-tolerant individual. Severe opiate withdrawal syndrome can be precipitated by drugs of this type. Alcohol and other central nervous system depressants should not be taken or consumed while methadone is being taken. Combinations taken in excess can lead to shallow breathing, respiratory failure, and, ultimately, death.

Reports have indicated that tramadol (Ultram and Ultracet) is more likely to induce seizure activity when given together with a selective serotonin reuptake inhibitor (SSRI [see list below]). Use of tramadol with MAO inhibitors or SSRIs increases the risk of adverse events, including seizure, serotonin syndrome, and even death. Use of tramadol with CNS depressants increases the rate of respiratory depression.

(These drugs can be dangerous when combined with tramadol. See above.)
  • Citalopram (Celexa, Cipramil, Emocal, Sepram)
  • Escitalopram oxalate (Lexapro, Cipralex)
  • Fluoxetine (Prozac, Fontex, Seromex, Seronil, Sarafem)
  • Fluvoxamine maleate (Luvox, Faverin)
  • Paroxetine (Paxil, Seroxat, Aropax, Deroxat)
  • Sertraline (Zoloft, Lustral, Serlain)
BL Drug Combo Fatality Reports
Methadone + Xanax
Tramadol + SSRI
Morphine + Xanax
Opiates + benzodiazepines (coma)

Please note that while some may use one of the dangerous drug combinations listed above at low doses without negative consequences, even a small step up in dose can multiply the health risk by a greater factor where drug combinations are concerned. A person in an altered state of consciousness does not always use the best judgment – so please be careful and ALWAYS error on the side of caution.

Information gathered and quoted from:
Cynthia Kuhn, Scott Swartwelder, and Wilkie Wilson from the Duke University Medical Center and their book "Buzzed" W.W. Norton and Co., 1999; web sources; and Bluelight members.
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Feb 6, 2000
melbourne, AU
Prozac is a SSRI (selective serotonin reuptake inhibiter) - ie it blocks the reuptake transporters to keep serotonin in the synapse.

MAOI stands for monoamine oxidase inhibitor. MAO is the stuff that breaks down serotonin and other neurotransmiters (like dopamine) after they get sucked back into the cell thru the reuptake trasporters.

SSRIs and MAOIs are very different. these two should not be combined. mdma and MAOIs should not be combined. SSRIs should not be taken at the height of a roll, but can protect the serotonin system following a roll.
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Aug 29, 2000
Buffalo NY.. but known to visit CFL now and then.
Originally posted by: fairnymph
posted 18 March 2001 04:35 AM

Remeron (mirtazapine) and mushrooms
-No medical evidence, just my own personal experience.
- I had extreme difficulty breathing for 1-2 hours, irregular, slowed heart rate. I almost went to the ER, but fortunately I got through the breathing bit. It may be because I run daily that my heart got me through, so I expect that for normal people the interaction would be even worse.
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May 2, 2001
This is mostly a list of cytochrome P450-2D6 inhibitors, which i suggested for addition here earlier. It mostly applies to DXM, but note that mixing any two drugs on the list may potentially be dangerous, since mixing a drug with potentially harmful effects (like DXM) with even small amounts of another cyp-2D6 inhibitor can cause both drugs to accumulate to dangerous levels in the body (since they can't be broken down). There's also some other stuff about MAOIs.

DXM + an MAOI is a dangerous combination; Robitussin DM is not okay, probably not even in normal doses. for a while, i took Manerix (moclobemide), which is a reversible MAOI, and was expressly warned never to mix it with cough medicines containing DXM. even though the dietary limitations for tyramine intake (like, no tomatoes, no cheese) don't apply to reversible MAOIs, there are still a few restrictions: no more than 300 g of aged cheese or 1000 g of any cheese, and no products derived from yeast, like Marmite and Vegemite. you also cannot mix them with DXM.
to many people, this may be irrelevant, because there are no reversible MAOIs approved for use in the US.

CYP-2D6 Inhibitors
There are a large number of drugs that inhibit the action of the liver oxidoreductase enzyme cyp-2d6 (cytochrome p450-2d6). This enzyme is responsible for metabolizing a number of drugs, including MDMA and methamphetamine. Mixing a cyp-2d6 inhibitor with MDMA or crystal, or mixing two or more inhibitors, is considered highly dangerous because it prevents you from eliminating the drug, meaning that it will be present in higher concentrations for a longer time.

This list of CYP-2D6 and CYP-3A inhibitors is from the DXM FAQ, with some annotations:
  • ajmalicine 2D6 strongest (164)
  • carbon monoxide poison 2D6 (160)
  • chloroquine antiparasitic 2D6 med-low (172)
  • chlorpheniramine (found in some cough medicines and anti-allergic preparations) antihistamine 2D med-high (151)
  • citalopram antidepressant 2D6 med-low (166)
  • clozapine antipsychotic 2D6 low (171)
  • desipramine tricyclic antidepressant 2D6 low (152)
  • diphenhydramine (Dramamine, Gravol, Benadryl) antihistamine 2D med-high (151)
  • doxorubicin anticancer 2D6 med-low (165)
  • fluoxetine (Prozac) antidepressant 2D6 med-high (152)
    [*]fluvoxamine (Luvox) antidepressant 2D6 med-high (152)
    [*]imipramine tricyclic antidepressant 2D6 med (152)
  • lomustine anticancer 2D6 med (165)
  • mepyramine antihistamine 2D6 high (151)
    methadone addiction treatment 2D6 med (162
    [*]moclobemide (Manerix) MAO-A Inh. (reversible) 2D6, also 2C19, 1A2 (147)
    [*]nortryptiline (Elavil) antidepressant 2D6 med-low (155)
  • oxamniquine antiparasitic 2D6 med-low (172)
  • paroxetine (Paxil) antidepressant 2D6 high (152)
    [*]PCP recreational 2D (150)

    - if this is true, then ketamine may be an inhibitor as well.
  • primaquine antiparasitic 2D6 med-low (172)
  • propranolol beta-blocker 2D6 low (156)
  • quinidine 2D6 (148)
  • quinine antiparasitic 2D (151)
  • sertraline antidepressant 2D6 med-high (167)
  • triprolidine antihistamine 2D med-high (151)
  • vinblastine anticancer 2D6 med-low (165)
  • vinorelbine anticancer 2D6 med-low (165)
    - Drug Uses P450-3A Enzymes Potency Ref
  • 7,8-benzoflavone 3A4 (activator) (153)
  • cannabidiol component of marijuana 3A med (161)
  • cocaine recreational 3A low (157)
  • clotrimazole agricultural fungicide 3A (activator) very high (154)
  • cyclophosphamide 3A low? (158)
  • ifosfamide 3A low? (158)
  • ketoconazole 3A (145)
  • pilocarpine cholinomimetic 3A low (149)
    - Drug Uses P450-3A Enzymes Potency Ref
  • 1-aminobenzotriazole Nonspecific med-high (159)
  • chlorophyllin geriatric Nonspecific (146)
  • general anaesthetics Nonspecific (163)
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Mar 16, 2001
Here are a few notes about interaction of recreational drugs with protease inhibitors and other anti-HIV/AIDS medications. All information taken from a 24 page booklet titled "Medical Drug Interactions with Street Drugs." The author is Julie Klems and she is affiliated with a group called Needle Exchange Emergency Distribution (NEED) out of Berkeley, CA, USA.

Doing speed or ecstacy even once can be deadly when taking these medications.

Anecdotally people say that you become very sensitive to speed, ecstasy and ketamine when on protease inhibitors.

Alcohol and sedative tolerance is also lowered by these medications.

Anecdotally people say that heroin, marijuana and cocaine have typical/usual reactions when taking anti-HIV/AIDS medications. Be warned, however, that cocaine dramatically increases the proliferation of the virus in your body. Avoid speedballs if at all possible; if you must get a fix, try to use heroin by itself.

The interaction of GHB with these medications is unknown but people are encouraged to exercise extreme caution.


Mar 16, 2001
Grapefruit Juice v2.0 -- written by frizzantik

This is not really about dangerous combinations, but anyone who'd read this thread would probably be interested in this information...

Grapefruit Juice FAQ

Grapefruit juice can act as a potentiator for the following prescription drugs sometimes used recreationally:
  • codeine
  • methadone
  • oxycodone (OxyContin, Percoset)
  • dextromethorphan (DXM)
  • alprazolam (Xanax)
  • clonazepam (Klonopin, Rivotril)
  • midazolam (Versed)
  • triazolam (Halcion)
Caution should be excercised if consuming grapefruit juice before or while taking these drugs. Though most people report mild potentiation (if any), if one is taking extremely large doses, any potentiation could be dangerous.

Method of Action
Grapefruit juice can inhibit the gastrointestinal activity of two enzymes known as cytochrome P450 CYP3A4 and CYP1A2, though the effect on CYP1A2 is minimal. This causes elevated plasma levels of some drugs, because they are able to pass into the bloodstream without being broken down by enzymes in the intestine. Due to variations in enzyme levels in the intestine from person to person, effects will vary.

The specific chemical responsible for this action is not known. There are a few suspects including various flavonoids and other phytochemicals called furanocoumarins. Concentrations of these compounds vary from one batch of juice to another. Higher concentrations are found in white juice compared to red, and the highest concentrations are found in the pulp of the fresh fruit. One glass (200 ml) of fresh juice was found to be equal in effect to two or three glasses of double strength reconstituted frozen juice. This suggests that store bought juice, which is often from concentrate, must be consumed in large quantites to for effects to be noticed. Consuption of 6-8 glasses of fresh juice may lead to inhibition of CYP3A4 in the liver. The potentiating effect of grapefuit juice may last 5 or mores hours after ingestion.

A Note on Codeine & Oxycodone
Codeine is metabolised by both CYP3A4 and CYP2D6. CYP3A4 metabolised codine into norcodine which isn't very active, while CYP2D6 metabolises codiene into morphine which is responsible for codiene's effect. When the CYP3A4 enzyme is inhibited by grapefruit juice, more codiene may be metabolised by CYP2D6. This is theoretical and is not supported by literature at this time.

Like codeine, oxycodone is metabolized by both CYP3A4 and CYP2D6, with the more potent metabolite, oxymorphone, produced by CYP2D6. When the CYP3A4 pathway is blocked, more oxycodone may be metabolised by CYP2D6.

Grapefruit Juice and Cimetidine (Tagamet)
Cimetidine acts on a different enzyme than grapefruit juice, specifically CYP2D6. CYP2D6 metabolises many opiates and opiods, but grapefruit juice has no effect on CYP2D6.

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