Expert: Dr Ian Jackson - please note UK based - 10/18/2009

Question
Is it possible and/or likely that a mix of drugs (esp. those that have strong interactions with one another) can have a synergistic effect on the length of time that side effects persist or even upon the severity of the side effects?

For example, if you were given in one day (within 2-3 hours): Versed, Valium, Fentanyl, Atropine, Propofil, Lidocaine, Marcaine, & Epinephrine, while already taking codeine & keflex --

Would this combination have any effect on an overdose (1 mg) of Halcion given 3 weeks later in a 95 lb female?

Are all of those in the first group highly reactive with one another, in which case, why would a healthcare professional use them all at the same time?

Do you know if it's possible for this combination, all given withing 3 weeks, to cause someone to exhibit lasting and debilitating psychotic behavior? -- someone who does not have a history of such behavior?

Answer
Hi Susan

The list of drugs you mention - midazolam, diazepam, fentanyl, atropine, propofol, lidocaine, bupivacaine and epinephrine can all be used together safely with codeine and cephalexin. However it would be unusual to use such a combination especially two different benzodiazepines (midazolam and diazepam). It sounds like a recipe that was used for a degree of sedation during a local anaesthetic procedure and they tried several different drugs. This does not happen in the UK and we would not consider using the above combination. However in itself there is no reason that they can't be used - though if you are only 95lbs it must have taken a while to recover.
Now the overdose of triazolam - this is not a drug we use in anaesthesia in the UK so I have no experience of its use. It does appear to be a large dose particularly in someone so light. Ater 3 weeks I would not expect the previous drugs to have any interaction with this however.
Now as to the psychotic behaviour - this is difficult to answer as first reaction is that single doses shouldn't cause any issue. However we do know that certain unlucky individuals with susceptability to psychosis can be set off by exposure to one off doses of street drugs. So I would have to say that the drug 'could' (I can't say did) lead to the issues you describe. I believe there is evidence that triazolam is linked to the development of psychotic symptoms.
I wish you all the best and hope that you improve.
Dr Ian Jackson