4mg clonazepam is way too much. More like 0.5-1mg but not too fast acting. Unless, of course, you have a huge tolerance.
Ativan is a decent option, 1-2mg to start, up to 4 if necessary, and it can be given i.m. if you have the proper formulation in vials (few will.)
Xanax is a poor choice, leads to amnesia, blackouts, nudity, etc. in the context of psychedelics/other drugs.
RC benzos are not well enough understood, stick with the tried and true.
Valium is ideal, 10mg-ish to start or more with tolerance, 5 if you're small or sensitive, up to 30-40 if you have a high tolerance. Librium probably OK too.
Bromazepam is good if you can get it.
A hypnotic like temazepam or Dalmane might be a decent option to knock you out totally, but I'd go with the anxiolytic options above.
Don't combine with booze or other downers.
also useful: hydroxyzine, an antihistamine sedative with 5ht2a antagonist qualities
anti-psychotics can be of some utility in the management of acutely agitated states, Leary recommends 50mg chlorpromazine i.m. which is probably a good starting place, in a clinical setting I'd use haldol 5/ativan 2 i.m. q1-2h until the patient is no longer agitated. Thorazine is appealing because it is promiscuous across different receptors, as LSD is albeit in the other direction, haldol a bit less so.
In re: Haldol and Thorazine, I'm talking about acutely agitated states and threat to sef/others, or a great deal of noise in your private residence that is going to attract untoward attention ... I used to keep a few vials/ampules on hand just in case an extreme situation were to occur when we were taking psychedelics, never had to use them. Kept 'em in my emergency kit with my narcan and BVM.
And actually, yeah, now that you'd mention it I'd probably add 50 benadryl to the 5/2, now that you mention it, but not too many times, for risk of delirium. Too much Ativan can also be disinhibiting. But anyway this is a rapid sedation protocol familiar to psych ER docs and while I would hope it would never be necessary to undertake it at the home or in a festival tent, I always came prepared to do so.
Zydis is not a bad choice, although I tend to go the more traditional route(s). As far as receptor promiscuity in neuroleptics go clozapine probably takes the cake but for obvious reasons isn't a good choice for acute administration. The classic choice in these cases has always been Thorazine but Haldol/Benadryl/Ativan 5/50/2 repeated as necessary is probably the best choice to rapidly bring down the severely agitated subject.
But yeah, Valium is my best recommendation, barring aforementioned severe agitation. Ativan a close second.
Also just the idea of having BZDs/a trip-stopper on hand can be of comfort with anxiety on the come-up anyway.
