Taking a pharmaceutical while undergoing a very tough experience should be viewed as your last resort.
The most well known drug used by emergency professionals is Thorazine, but it is extremely psychologically hard on the recipient.
Most acute crisis which land someone in the care of an emergency professional are the result of intense anxiety. Psychedelics can and do precipitate uncontrollable feelings of anxiety, fear, paranoia, and other agitated states. According to medical professionals who have experience dealing with psychedelics, the primary pharmaceuticals used to treat these acute agitated states are the benzodiazapenes such as Valium or Xanax.
"If all psychological approaches fail and tranquillizers have to be used, it is much better to start with Librium (30-60 milligrams) or Valium (10-30 milligrams), which seem to alleviate painful emotions without interfering with the course of the session. As soon as possible, the patient should resume a reclining position with eyeshades and headphones, to continue the introspective approach to the experience."
- Stan Grof, LSD Psychotherapy
Haloperidol - An antipsychotic drug used to treat acute and chronic psychosis and is "considered particularly effective in the management of hyperactivity, agitation, and mania."
Risperdal (risperidine / risperidone) - A somewhat newer antipsychotic often considered the first choice among the anti-psychotics for treating extreme acute hallucinogen-induced psychotic episodes because of its high affinity for 5HT2a receptors. Anti-psychotics are not generally used to treat panic reactions or other psychedelic crisis which do not involve acting out.
Thorazine (chlorpromazine) - An antipsychotic with a large number of unpleasant side effects, a distant third or fourth choice when treating most psychosis or anxiety. "Thorazine and Mellaril are antipsychotic agents in a class called phenothiazines. They are excluded for use in the elderly because they do not have a very favorable side effect profile. If an agent is needed to control acute episodes of threatening behaviors or aggression, newer antipsychotic drugs like Risperdal or Haldol are preferred. "
Geriatric Drug Review]
Thorazine and other major tranquillizers are not specific neutralizers of the LSD effect. Used in high dosages, they have a general inhibiting effect that overrides and masks the psychedelic action of LSD. Detailed retrospective analysis of this situation usually shows that the patient experiences the action of both drugs simultaneously, and that the combined effect is rather unpleasant."
- Stan Grof, LSD Psychotherapy
reating a psychedelic crisis with Thorazine is to be avoided and is considered a form of extreme mental torture and has been known to result in weeks or months of psychological trauma for the person treated with this "mental straightjacket" while in the middle of a psychedelic crisis.
Valium (diazepam) - is used to treat anxiety and muscle spasms, as well as generally calming people down. Dosage used is between 2 and 10 mg for low level anxiety and 10-30 mg for acute, extreme attacks. Valium is schedule IV in the US partially because some people find the effects pleasant enough to use them recreationally. Valium, Xanax, and other equivalent benzodiazepines are considered by some members of the psychedelic community to be the best chemical treatment for extreme psychedelic crises.
Xanax (alprazolam) - Another benzodiazepine (like Valium) used to treat anxiety, muscle spasms, and to calm people down. Xanax comes on more quickly than valium and is considered more useful for treating acute episodes. Xanax pills are sometimes chewed to speed onset, although the taste can be unpleasant and soda, water, or fruit may be necessary to reduce the bitterness. Dosage for Xanax is .25-1 mg for low anxiety, and 1-3 mg for extreme acute attacks. See Valium. Xanax may be somewhat more sedating than Valium.