Demerol on its own:
http://www.rxlist.com/demerol-drug.htm
"...SIDE EFFECTS
The major hazards of meperidine, as with other narcotic analgesics, are respiratory depression and, to a lesser degree, circulatory depression; respiratory arrest, shock, and cardiac arrest have occurred..."
Demerol With Xanax, a tranquilizer.
(Same url) "Demerol
"Dosage should be adjusted according to the severity of the pain and the response of the patient. Meperidine is less effective orally than on parenteral administration. The dose of DEMEROL should be proportionately reduced (usually by 25 to 50 percent) when administered concomitantly with phenothiazines and many other tranquilizers since they potentiate the action of DEMEROL..."
Demerol with Zoloft, an SSRI (a serotonin reuptake inhibitor):
Drugs.com
"Zoloft (sertraline) and Demerol HCl Interactions
Interaction(s) found:
meperidine and sertraline (Major Drug-Drug)
MONITOR CLOSELY: Concomitant use of agents with serotonergic activity such as serotonin reuptake inhibitors, monoamine oxidase inhibitors, tricyclic antidepressants, 5-HT1 receptor agonists, ergot alkaloids, lithium, St. John's wort, phenylpiperidine opioids, dextromethorphan, and tryptophan may potentiate the risk of serotonin syndrome, which is a rare but serious and potentially fatal condition thought to result from hyperstimulation of brainstem 5-HT1A and 2A receptors. Symptoms of the serotonin syndrome may include mental status changes such as irritability, altered consciousness, confusion, hallucinations, and coma; autonomic dysfunction such as tachycardia, hyperthermia, diaphoresis, shivering, blood pressure lability, and mydriasis; neuromuscular abnormalities such as hyperreflexia, myoclonus, tremor, rigidity, and ataxia; and gastrointestinal symptoms such as abdominal cramping, nausea, vomiting, and diarrhea.
MANAGEMENT: In general, the concomitant use of multiple serotonergic agents should be avoided if possible, or otherwise approached with caution if potential benefit is deemed to outweigh the risk. Patients should be closely monitored for symptoms of the serotonin syndrome during treatment. Particular caution is advised when increasing the dosages of these agents. The potential risk for serotonin syndrome should be considered even when administering serotonergic agents sequentially, as some agents may demonstrate a prolonged elimination half-life. For example, a 5-week washout period is recommended following use of fluoxetine before administering another serotonergic agent. If serotonin syndrome develops or is suspected during the course of therapy, all serotonergic agents should be discontinued immediately and supportive care rendered as necessary. Moderately ill patients may also benefit from the administration of a serotonin antagonist (e.g., cyproheptadine, chlorpromazine). Severe cases should be managed under consultation with a toxicologist and may require sedation, neuromuscular paralysis, intubation, and mechanical ventilation in addition to the other measures."
Page 10 of http://www.lucire.com.au/documents/pdf/RefocussingUpstream.pdf
"...Responses to any medication are governed by three genetically determined systems: transporters, receptors and cytochromes. There is also drug sensitivity, just like allergy to penicillin, and CYP450 metabolism might be normal in those cases.
We know nothing that can as yet be clinically applied about the first two, but genetic testing is available for CYP450 polymorphism..."
Charts are available to predict reactions to and interactions between drugs that are metabolised by CYP450.
These charts go a long way to elucidate adverse drug events, which are clinically visible but universally unacknowledged and unrecognised in Australia.
Note that the use of one drug, such as Aropax (and other "SSRIs") can turn a rapid metaboliser into a poor metaboliser by inhibiting cytochrome P2D6 needed both to metabolise itself and often more so for the second drug. That is one of the reasons that polypharmacy is a pernicious practice..."
