Well, firstly I need to ask you, it is the phenobarbital part of a pain killing ingredient, something like the Tylenol type of drug that it is having a combination of 2 different drugs?? I mean, I need to ask this because I have never ever heard of phenobarbital to be used as an ingredient for a pain killing drug. So, I guess that I need to ask you: whether have you been rx’d phenobarbital to use along with a pain killer drug or no?
I’m not sure if you know it or no but phenobarbital is having no known analgesic properties, it is only a theoretical usage of it in the treatment of a kind of pain due to its anti spasmodic qualities and this can be pretty useful for the back injuries, mostly (or I can say only). Let me give you an example, the low dose Diazepam is occasionally given to patients (of course prescribed) along with a pain killer (also prescribed) for this purpose. This is due to the fact that these 2 combined are able to heal those painful spasms that are accompanying those types of pain cases.
However, as much as I know, phenobarbital is having only a few approved usages in nowadays in medicine. That’s due to the fact of it’s pretty short therapeutic index – it has been established that it is very and very easy to overdose on barbiturates due to the very and very narrow margin between the dangerous dose and the safe dose so you should be EXTREMELY careful when used. The biggest and main purpose in the late days for this one it is only for a certain few types of seizures as well as few epilepsy states. Besides, it is also having a controversial place in some detoxification treatments for people that are having alcohol or/and benzodiazepine addiction. I know that benzodiazepines have taken almost every single place of barbiturates in nearly every single area that these 2 types of drugs are inhabiting and here I can mention for example: anxiety, insomnia, epilepsy as well as pre med sedation. Once again, I have said in ALMOST and NEARLY everywhere because it is still pretty much used as an anesthesia induction in some hospitals, however, one sure thing is that this is under a very strong and highly supervised circumstances and also it is being very important that it needs to be administered by an specialist, by an anesthetist.
I really don’t want to seem rude or anything but, with respect, your question seem to me to be puzzling due to the fact that what are you asking: what is going to happen in case an “otherwise healthy person” is taking phenobarbital. After that you are saying that this is only a part of a pain killer that you have been given by a doctor, however this makes me to have the assumption that you are being unwell or you need it for a special and certain condition that you should be aware of.
In case you have been given this medication by a professional doctor (prescribed) then it should be done for a diagnosed health issue and then there should be no problems for you to use this medication as it is being prescribed by your pharmacist and your doc. in the other hand, in case this is not the exact case then in only my personal opinion , if I would be you, I would tread extremely and extremely carefully around on using phenobarbital. This is very and very serious and using it with no doc’s supervision it can be very and very asking for additional and unwanted problems. as I have said this thing earlier in the post, it is extremely easy to overdose on phenobarbital. There is one more reason for this apart from it very narrow therapeutic index, you should know that phenobarbital is causing very significant anterograde amnesia which would make you to fall asleep extremely and extremely easy which later, you are going to wake up approximately one hour or maybe 2 hours later while you have totally forgotten that you have previously used your dose and because of this you are going to re dose once again. I know what I am talking about because there was a woman I knew myself and she has died like this. I know a lot of other people like this one but they were not my “friends”.
Anyway, as a final conclusion to all of this, I only can say that this is only my personal and subjective opinion which does not give me the right to tell you if you need to use this drug or you should not. but, what I do want to tell you is that you need to be very careful if you want to use it, and that’s especially in case you are not using this med while you are under a doctor supervision. I know myself that there are a lot of people thinking that they do not need doctor’s care but when they have done it the wrong way and they have only made it all worse than they understand that they need the doctor’s care. And there are such cases when they have done it so bad that the doc’s can’t help them and in the end of the day guess who is the bad person? Of course the doctor. I just want to help, otherwise I would not be writing this long post. Hope you would be healthy.