well let's be more clear about what falls under which category of contraindicated substances (non-exhaustive list):
Depressants (substance that have a depressive effect on the central nervous system):
alcohol, kava, sedatives, sleep-aids, tranquilizers, anxiolytics, analgesics, anaesthetics, benzodiazepines (for instance diazepam aka valium, etc..), poppies, opium (and poppy extract), heroine, morphine, codeine, opiates & opioids, ketamine, pcp, dxm, ghb & gbl, ether, LSA.
In other words, any substance that can make one feel sleepy, drowsy, sedated.
Note that excess of any depressant substance can lead to respiratory depression, come, convulsions, suffocation and death.
Substances causing bradycardia (slow down heart beat):
this is the case of quite a few depressants, notably ketamine and heroine.
Foxglove (digitalin) is also known to cause severe bradycardia.
Note that excess of any substance causing bradycardia can lead to hypotension, cardiac arrhythmia(=irregular heart beat) and periferal vasoconstriction (=contraction of blood vessels in body extremities, which are left poorly irrigated with blood, possibly causing necrosis of extremities in the most extreme cases).
Substances causing hypotension (decrease blood pressure):
dimenhydrinate (aka dramamine) and related medecines, sinicuichi...
Note that excess of any hypotensive substance can lead to periferal vasoconstriction, bradycardia and cardiac arrhythmia.
Stimulants (substance that have a stimulating effect on the central nervous system, making you feel speedy):
cocaine, crack, exstasy, amphetamines (speed), methamphetamine, phenethylamines (mdma, mda, mescaline, and 2C's such as 2c-b are all phenethylamines), ephedra, ephedrine, pseudoephedrine, herbal exstasy, khat, yohimbe (yohimbine).
Note that excess of any stimulant substance can lead to hypertension, tachycardia (fast heart beat) and arrhythmia, and therefore it can be really dangerous for one's heart (cardiovascular incident).
Substances causing hypertension (increasing blood pressure) and/or tachycardia (accelerating heart beat):
That is the case of many stimulants such as cocaine, excstasy, amphetamines (speed), metamphetamine, phenethylamines (mdma, 2c-b...), ephedra, ephedrine, pseudoephedrine, herbal exstasy, khat. It's also the case for a few tryptamines (such as 5-meo-dmt), amanita muscaria (fly agaric mushroom), solanaceae plants such as datura (atropine, scopolamine), dxm, yohimbe (yohimbine), and also many aphrodisiacs which action is to cause elevated blood pressure and vasodilatation.
Note that excess of any hypertensive substance can lead to serious cardio-vascular incident.
Substances causing vasoconstriction (contraction of blood vessels):
pseudoephedrine, ephedra & ephedrine (and therefore herbal exstasy also), LSA (contains ergines with powerful vasoconstrictive properties, notably ergometrine), ergot alkaloids (ergotamine, ergometrine and quite a few other ergines...), dimenhydrinate (aka dramamine), cocaine and crack , adrenaline, noradrenaline, dopamine.
Note that any substance causing serious vasoconstriction can lead to hypertension, tachycardia and arrhythmia, so there's a real risk for one's heart (cardiovascular incident)
Substance causing vasodilatation (dilatation of blood vessels):
yohimbe, yohimbine, poppers and also quite a few aphrodisiacs which action is to cause elevated blood pressure and vasodilatation.
Note that excess of any substance causing pronounced vasodilatation can lead to cardiovascular incident.
All of these are to be avoided when using IMAO's!
If you wanna mix a chemical or plant with IMAO's, you have to do your own researches to ensure that this substance does not fall under any of these categories (as obviously I could not list every known chemicals and plants in here, so many are lacking)
PS: of course, keep in mind that one should not take IMAO's along with tyramine nor when using antidepressants (especially tryciclic antidepressants). See my previous post.
