1. How long will it take for the medicine to work?
It may take a number of weeks to find the right dose, and even more time for your healthcare provider to know how well the medicine works to control your seizures. How long this takes will be different for each person. It may require 14-21 days to achieve the steady therapeutic blood concentrations. Factors affecting dose optimization include how often you have seizures, what other medicines you may be taking, and how your body responds to phenobarbital.
2. How long will my phenobarbital level have to be monitored?
In general, your levels will need to be monitored as long as you are taking the medication. Phenobarbital, like other anti-epileptic drugs, is usually taken every day (sometimes several times a day) for your lifetime. Exceptions to this may be adults who have outgrown their epileptic syndromes from childhood or people whose seizures are caused by a temporary condition and only need the medication for a limited time.
3. Will phenobarbital affect other medicines that I am taking?
It might. Be sure to tell your healthcare providers the names of all prescription medicines, herbal or dietary supplements, vitamins, and over-the-counter medicines you take. Some of these may interfere with how phenobarbital works, lowering or raising the level in your blood. Phenobarbital may also affect how other medicines work.
4. I am taking the drug primidone. Why is my doctor monitoring phenobarbital?
Primidone is another medication that is used to control seizures. Phenobarbital is the major breakdown product (metabolite) of primidone that is also active in controlling seizures. To ensure that there is enough active drug in your blood to control your symptoms without causing toxicity, your healthcare provider may monitor phenobarbital when you are prescribed primidone.
This article was last reviewed on August 23, 2015. | This article was last modified on August 23, 2015.
The review date indicates when the article was last reviewed from beginning to end to ensure that it reflects the most current science. A review may not require any modifications to the article, so the two dates may not always agree.
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