Question
Will dolutegravir effect how much metformin my body absorbs?
22 March 2022. Related: All topics, Drug interactions.
I have a question regarding the dosage of dolutegravir and metformin when taken together.
I have been on dolutegravir since 2020 and my doctor prescribed me metformin 1000 mg daily.
On the Liverpool HiV drugs interaction site it says that daily 50 mg dolutegravir dose significantly increases drug levels of metformin.
My doctor doesn’t know about my HIV positive status, can you please advise if I should take half tab of Metformin (together with DTG) or just 1000 mg as it is prescribed by my doctor?
Answer
Hi, how are you doing?
You are correct, there is an interaction between metformin and dolutegravir and this should be monitored.
This is because doultegravir can significantly increase how much metformin is absorbed by the body. This means there is a risk of hypoglyceamia (low blood sugar) if the metformin levels are too high.
The recommended starting dose of metformin is 500 mg twice daily (total 1000 mg a day) when taken with dolutegravir 50 mg once-daily. However this needs to be monitored by your doctor because of the risk from higher levels of metformin.
The Liverpool website also reports that metformin levels are increased even higher when dolutegravir is taken at 50 mg twice a day, which a few people might still do.
In addition, kidney function needs to be monitored at the same time when you start to use both medicines together. This is because metformin is cleared from the body by the kidneys. If you already have low kidney function this could increase level of metformin including to very dangerous levels.
Please discuss this with your doctor? At i-Base we are not doctors and cannot suggest dose adjustments, just information about drug interactions.
Also, any changes in dosing should only be after discussion with your doctor.
If the metformin is prescribed by a general doctor who doesn’t know about your HIV meds, please talk to your HIV doctor instead.
This is very important.
Josh.
Hi Nnete, thanks – it is important to discuss this with your doctor as metformin levels that are too high can be very dangerous.
Thank you so much I have on both in metformin and dolutegavir and understand I need to have kidney function tested.