Using iboga anywhere near these types of drugs can be VERY dangerous, as iboga works on such a large number of neurotransmitters, with serotonin being a major one, anything that effects this heavily, needs to be completely out of the system, and sometimes quitting cold turkey can cause problems. I would suggest asking the doctor what is the quickest and easiest way to get off of all those types of medication as safely as possible, before even thinking about using iboga/ibogaine. Serotonin syndrome would be horrible, and possibly fatal!
Any anti-depressants, or anti-psychotic medications should be discontinued safely before using iboga. Benzodiazepines are safe with iboga. But various OTC supplements can have negative interactions, as well as some foods, or drinks can even be a bad idea. For instance, white grapefruit juice, which inhibits an enzyme in the liver that breaks down various other drugs (potentiates opiates and other drugs), can effect the metabolism of ibogaine. If you go to a provider, you must be sure to be 100% honest and tell them any and all medications, supplements, herbs, etc. that you have taken within the last few weeks to months.
This doesn't mean you can't get treatment, but it can possibly delay it, until it is safe for you to undergo such a serious and powerful experience. Those with a history of mental illnesses could also be a bad idea in a lot of cases, just as with any psychedelic, however, many tribes would use it in this way for certain, specific ailments.
It works extremely well for beating various addictive substances and habits, but many drugs are very dangerous with iboga and it may or may not help with withdrawal for any of these. Although, it is my belief, that in some cases using iboga properly can eliminate the source of the problem you began taking the pharmaceuticals for in the first place. But that is just something I like to believe, I have only anecdotal stories to tell about some of these types of healing reports.
Keep in mind, though, the Bwiti have been passed down knowledge and rituals for thousands of years, and with the limitations on our western research, the ability to rethink in new ways, and communicate as well as we should to learn certain benefits from the ancient traditions, there is very little hard data in using iboga for healing other various ailments. Also, the indigenous use probably has very poor data recorded in many of the remote areas where it is used as a medicine, along with probably a whole other slew of local herbs and plants with healing properties, that they use as well.
I suspect it could be beneficial in a lot of cases that aren't necessarily considered something you'd treat with iboga, but to find more than anecdotal evidence, there really isn't enough scientific data on it, other than for addiction interruption, nor are studies being done to really find the full treatment capabilities.
There are reports of people quitting xanax with an iboga total alkaloid extract, but stopping those cold turkey can also cause seizures in some cases, so just because I read that someone did it, doesn't necessarily mean that I wouldn't taper down as the doctor suggested before quitting them completely. For those with that problem, ideally, IMO it would be best to do so before the flood, so the iboga has an easier job fixing your imbalances, and you can start off right away developing new healthier patterns, which is the key to success.
One old habit, helps you fall back into another, and so on. Starting off clean and fresh after an iboga experience, while making conscious choices to build the life you envision for yourself, is the way to use iboga to improve your life. It can provide withdrawal relief, especially for opioids/opiates, and craving relief for a multitude of other drugs/negative behaviors. It can improve mood and outlook on life, and allow you to view it from a new perspective. It can help you break addictions to things you never realized you were addicted to, such as sugar, caffeine, other self destructive habits, etc.
But this is not universal for everyone who takes it. Some aren't ready, some don't have the discipline or focus to stick with the path, some don't have their therapeutic/mental health issues worked or sorted out, some lack a support group they can turn to, and some are just wired differently, I suppose.. Some people miss the message completely, when being overwhelmed by the sometimes difficult physical experience, and they forget about all the benefits that they could look at during and afterwards.
I'd say, get clean of anything that's possibly dangerous (obviously opiates are something you don't want to take with it, but you can dose iboga when you begin to feel withdrawal starting, for those who need it for that purpose), find a provider (that you truly feel comfortable with in every way), or a sitter that is willing to research all kinds of safety precautions, what to watch for, one who is not the type to freak out should you start saying or mumbling crazy things in a trance, but will do something should anything get serious/dangerous. They should read all the available internet information, and preferably have some background in psychedelics.
You might even wish to sign up over at
http://eboka.info to get more advice, find some professional treatment providers, and other very experienced members, that would also be happy to chime in on their thoughts, ideas, experiences, and safety recommendations.
If you find someone that you feel comfortable with, can trust, and offers a reasonable price, or you find your own sitter and supply, then start planning how you'd go about it all. I'd also pick up a small amount of root bark, and try some micro-doses (300-1000 mg powdered bark), and when comfortable, maybe even possibly work your way up to a few grams of bark over a couple hours, by just swallowing the ground bark and washing it down with some juice or water, until you get a nice little buzz going. Then lay back, relax, close your eyes, and sort of get to know iboga, without taking the full plunge. This can definitely be beneficial itself, and can also help you get familiar with the material, and probably make you feel a lot more comfortable when it's time to go for the flood dose!
But again, not until you're off any pharmaceuticals. (SSRI/SNRIs are bad news with iboga!)
Good luck!