News • Blog
Sexual health and LGBT population
Living with HIV
Post-exposure prophylaxis (PEP)
In order that your medications may be effective and active against HIV, they must be digested and absorbed by your body. The medications must get into your bloodstream, via the digestive system (stomach and/or intestines). Once this is achieved the medications need to be modified or "metabolized" by your liver or your kidneys such that they may ultimately exert their action by impeding HIV replication at the level of your CD4 cells.
Some of the more common factors that may have an influence on the absorption and/or metabolism of medications include:
Some medications need to be consumed with food, while others need to be taken on an empty stomach (fasting). Some medications have absolutely no dietary restrictions whatsoever. This is important to be aware of, given that food can exert, in certain cases, a significant impact on the absorption and metabolism of many medications. As a result, the presence or absence of food may serve to increase the levels of medications circulating in your bloodstream and may thereby increase the level of side effects. In contrast, some foodstuffs may actually decrease the level of medication in your system thus exposing you to levels inadequate to manage your HIV infection...this creates the ideal environment for the development of medication resistance.
While dietary constraints or restrictions may be a nuisance, when respected to the letter, they serve in the prevention of resistance. It is extremely important to inform yourself as to the dietary restrictions/permissions developed for your particular medications - ask your physician, and review from time to time with your pharmacist...particularly when modifications to your regimen are prescribed.
Given that your medications need to be digested and absorbed along the length of your intestinal tract (stomach and intestines), if you are suffering from nausea, vomiting and/or diarrhea, these symptoms may have a negative impact on the digestion and absorption of your meds - when you are ill, from gastroenteritis, flu, etc.. and can't keep your medications down: speak with your physician and/or pharmacist as to how to manage your particular situation.
As is the case with certain foodstuffs and medications, there are several medications and/or homeopathic products that can exert a significant influence on the absorption or metabolism of your antiretrovirals. When the absorption or metabolism of a given medication is influenced by another medication or product, this association is termed an "interaction". Many medications, even those sold over-the-counter can have an impact on your anti-HIV medications. In addition, it is important to realize that even though labeled as "natural products", certain homeopathic interventions can cause significant interactions with your antiretroviral medications. As was described with certain food-drug interactions, some of these "natural products" may increase the blood level of your medications (raising the risk of side effects), while others may lower the therapeutic level of your medications (increasing the risk of mutations and eventual drug resistance).
Your pharmacist can assist you in determining the presence/absence of possible interactions between your antiretrovirals and any other medications/products you may be taking...or need to take in the future.
Whenever something is added - ensure that a revision of interactions is done - even with over the counter and natural products.
It must be stated that while absorption and metabolism difficulties do exist, they are not the principle causes of antiretroviral drug resistance. The primary reason is the difficulty to consistently adhere to the treatment regimen. Missed or forgotten doses permit levels of medications in your system that are unable to completely suppress HIV (sub-therapeutic levels). Sub-therapeutic levels encourage the reproduction, in the face of a small amount of medication. This scenario creates an ideal environment for the development of mutations able to circumvent the medications on board...resistance. It is important to stress the critical role that you hold in the prevention of resistance. No resistance = a therapy that will suppress HIV indefinitely. One of the greatest challenges facing individuals living with HIV and antiretrovirals is devising a system that ensures 100% medication compliance - not a single dose missed. Ever. Given human nature, this is not an easy task - remembering to take several medications every day...sometimes more than once per day. That being said, compliance to your medication regimen is the key to long-term control.