re: Diphenhydramine necessitating bronchodilator, etc
Regarding the issue of using a bronchodilator with diphenhydramine/dimenhydrinate, or any antihistamine. IMHO, this is just bunk. I think I know the webpage where you read this, or at the least, I have read the same on other web pages, and I don't believe this to be an accurate statement.
Being a cough suppressant has nothing to do with the respiratory drive or with bronchoconstriction/dilation. I think the original author of the statement you refer to got confused regarding cough suppression and respiratory depression. These are two separate and different things.
First, diphenhydramine is not a cough suppressant in the same way as opiates and dextromethorphan (DXM) are. It reduces cough by drying the airways, mostly as a result of the anticholinergic effects of the antihistamines (which are not very receptor selective drugs). DXM and opiates act directly on the cough reflex center to decrease cough.
Even if antihistamines did act on the cough reflex, excessive cough suppression does not equal respiratory depression. This can be seen in the huge, recreational doses of DXM taken by many people. DXM has no opioid activity, and thus does not cause respiratory depression. However, it does act on the cough reflex center and decreases cough. Doses of up to 1000 to 1500mg (30 to 100 times the effective cough control dose) produce no real alterations in respiration.
Respiratory depression can be caused by many things. An opiate overdose can decrease respiratory drive by the effect of opioids acting on opiate receptors within the respiratory control circuitry in the brain. This can be deadly in overdose. Antihistamines can also cause respiratory depression in overdose, but by a distinct pathway than from opioid induced respiratory depression. Antihistamine induced respiratory depression is likely due to a mixture of both antihistamine and anticholinergic effects, is seen only in massive overdose, and a bronchodilator (or opiate antagonist) would do little to counteract this effect.
There is no direct pharmacological link between the supposed cough suppressant effects of antihistamines, the cough suppressant effect of opioids, the respiratory depression caused by opioid overdose, nor the respiratory failure induced by massive antihistamine overdose. There is no good reason to take a bronchodilator with an antihistamine to protect you from respiratory depression when abusing narcotics. If anything, more drugs is just going to result in more side effects and you dying more easily.
As for the amount of alcohol in antihistamine or other medical syrups or elixers, unless you plan on drinking a volume comparable to the amount of vodka you would drink on a bender, you are not going to get any real alcohol effects. The percentage of alcohol in medicines is small (generally), and the volume you consume is small (compared to how much we drink when we are drinking).
Lastly, adding lorazepam will probably potentiate your opiate high, due to the sedative and modest mood elevating effects of lorazepam (similar to a few drinks, but without the ugliness of alcohol). It will also increase the respiratory depressant effects of opioids (i.e. to many Lorries with your Opies = huge oxygen savings
...Before the Wake said of diphenhydramine and opiates... "This mixture should be taken with a bronchodialator/decongestant because diphenhydramine is also a cough suppressant. The green label version of Alka Seltzer cold medicine contains a sufficient dose of decongestant and sodium bicarbonate (which slows metabolism). If the diphenhydramine product contains alcohol, the loading dose of the opiate should be reduced by 30% and the any booster doses should be taken no sooner than an hour afterwards."
Can anyone explain the recommendation of a bronchodilator/decongestant? What would be an example I could throw in the mix (Lorazepam (prescribed), Zoloft, Tylenol 1s (CWE))?
Can't find this "green label Alka-Seltzer" either.
...
What about Gravol (Dimenhydrinate)? [Better/worse than Diphenhydramine? Dosage info? Decongestant a requisite/recommendation as with Diphenhydramine?]"