What To Avoid When Taking Metformin | Drug Interactions | Pharmacology
Hi everyone this lesson is on what to avoid if you are taking metformin so we’re going to talk about some beverages and dietary choices that can influence the side effects that can occur from metformin but most of this lesson is going to be basically a pharmacology lesson where we’re going to talk about a lot of medications that can interact with metformin before
We get into those interactions let’s talk about what metformin is metformin is a medication used to lower or reduce blood glucose levels it lowers blood glucose levels by several mechanisms these include inhibiting gluconeogenesis in the liver which is the production of new glucose from other nutrient substrates metformin also inhibits glucose uptake from the
Gastrointestinal system and it increases insulin sensitivity so multiple mechanisms to lower the blood glucose level which is important when metformin is used for conditions like type 2 diabetes and other conditions like polycystic ovary syndrome however metformin can cause a variety of mild and severe side effects some of these include hypoglycemia which is a low
Blood glucose level so it can lower the blood glucose level too much although this is a rare side effect but we’re going to talk about some other medications that can interact with metformin to increase the likelihood of this happening and metformin can also lead to some other side effects including headaches diarrhea and also a severe condition known as lactic
Acidosis where the blood becomes acidic so those are some severe side effects that can occur and this is why it’s important to make note of some things that can increase the risk of these side effects from metformin use before we get into those there are certain patient characteristics that increase the risk of having side effects one of them is liver disease another
One is kidney disease another one is heart disease and having a recent myocardial infarction or a recent heart attack can increase the risk of having these side effects as well and then a previous allergic reaction to metformin if someone has had a history of an allergic reaction metformin this is also another risk factor as well so most of these liver disease
Kidney disease and heart disease if a patient does have them and they’re on metformin they are at an increased risk for lactic acidosis so very important to recognize if a patient has these patient characteristics but there are other factors that can increase or decrease the risk of metformin side effects we’re going to talk about those in the next upcoming slides
So some dietary choices can increase the risk for metformin side effects these include alcohol consumption especially excessive alcohol consumption so drinking alcohol again especially heavy alcohol consumption can increase the risk of lactic acidosis this is the very serious condition that we talked about before and it’s very important to recognize now alcohol can
Also increase the risk of hypoglycemia which is a low blood glucose level or low blood sugar so very important to recognize as well so for patients on metformin it’s important to avoid alcohol consumption or at least limit alcohol consumption because this alcohol consumption can also contribute to liver disease which can also increase the risk for lactic acidosis
As well and another important point to make note of here is that if there is excessive alcohol consumption and excessive exercise around the same time this can lead to an increased risk of hypoglycemia as well for patients that are on metformin so i just want to mention that here as well grapefruit consumption may also increase the risk for metformin side effects
As well so consuming grapefruits and or grapefruit juice can increase the risk of side effects from many many different medications the reason is is because grapefruit and grapefruit juice can inhibit certain enzymes in the liver that metabolize many different medications now this is a bit controversial with regards to metformin it may cause an increased level
Of metformin to accumulate within the liver which can ultimately lead to an increased risk of lactic acidosis but there is limited evidence with regards to this so although grapefruit consumption can increase the risk of side effects from many different medications because of its interaction and inhibition of drug metabolism the evidence with regards to metformin
Interactions with grapefruit and grapefruit juice is limited at this point but i want to mention that here as well now let’s talk about different prescription medications that can interact with metformin to increase the risk of side effects from metformin before we get into those it’s important to consult your physician or health care provider with regards to the
Following medications so if you are on these medications it’s important not to stop them before talking to your health care provider some of them are going to be contrast media now this is going to be important when you’re in hospital and getting imaging done contrast media can interact with metformin some of these include iodinated media ioversol and metrizimide
So these are some contrast media that can interact with metformin what they do is that they actually decrease the renal clearance of metformin leading to elevated concentrations that can ultimately increase the risk of some of those side effects we talked about before including lactic acidosis there are certain chest pain medications that can also interact with
Metformin these include renault zine so rinalizine can interact decreasing the elimination of metformin leading to increased levels of metformin so again another important medication to recognize so as you can see there’s going to be many different medications we’re going to talk about here so it’s going to be very pharmacology focused so it’s going to help a lot
With pharmacists and pharmacy students for the next upcoming slides some other medications that can interact with metformin include tefenoquin which is an anti-malarial medication so you can remember quinn chloroquine would also be another anti-malarial medication but this one specifically tethenoquin can increase the level and effects of metformin so this is one
To avoid if a patient is on metformin celegiline is also another medication that can interact with metformin celegiline is a monoamine oxidase inhibitor it’s actually a parkinson’s disease medication and if a patient is on this this can increase the level and effects of metformin as well we can also see certain diuretic medications interacting with metformin to
Increase the risk of side effects from metformin so certain diuretics can increase the risk of lactic acidosis so it’s important to monitor them especially in patients with other underlying health conditions so a lot of times these diuretic medications are going to be used in patients who have liver disease and have heart disease so it’s important to monitor these
Patients especially if they’re on metformin as well to make sure that they are not going to experience lactic acidosis one of those diuretic medications is the very commonly used diuretic known as furosemide or lasix some carbonic anhydrase inhibitors can also interact with metformin to increase the risk of side effects from metformin use so certain carbonic anhydrase
Inhibitors can increase the risk of lactic acidosis and these include to pyramid and methazolamide so these are very important to recognize as well and topiramate is used for treating migraines in epilepsy and methazolamide is a treatment for glaucoma so two medications that should be thought about when a patient is also on metformin because these both increase the
Risk of lactic acidosis certain antibiotics can also interact with metformin as well these include the fluoroquinolones like moxifloxacin in ciprofloxacin macrolides like chlorethromycin and trimethoprim which is part of ceptra and cephalexin as well so use of these antibiotics may increase the risk of lactic acidosis the interactions are going to be a little more
Minor but if a patient is taking these antibiotics along with some other medications that cause minor effects on metformin they can accumulate and increase the risk of lactic acidosis some other commonly used medications that can interact with metformin include the ace inhibitors like ramipril lysinopril and kaftapro these actually increase the effects of metformin
And they may increase the risk of hypoglycemia so this is going to be very important to think about because a lot of patients can be on ace inhibitors and also be on metformin so again the risk is going to be very minor but if a patient is on some other medications that also cause very minor changes in the way metformin works they can add up and cause or increase
The risk of certain side effects and with regards to the ace inhibitors they can increase the risk of hypoglycemia the use of certain antidepressants can also interact with metformin these include the ssris like sertraline which is zoloft fluoxetine which is prozac fluvoxamine acetylopram and paroxetine bupropion can also interact with metformin as well most of them
Are going to have very mild effects some antidepressants increase the levels of metformin others increase the effects of metformin so again very very mild effects on metformin pharmacodynamics but with multiple medications if a patient is on multiple medications is important to think about because these can increase levels or increase the effects of menformin we can
Also see interactions with symetidine submedidine is actually an h2 blocker used to treat heartburn so use of cementitine may increase the effects of metformin as well now those are some more commonly used medications that can interact with metformin to increase the risk of metformin-induced side effects but there are other medications that can also do this as well
If you want more information on all the medications that can interact with metformin please check out some of the resources on some other medical reference websites for more information on this now i want to end this lesson on something that can actually reduce the risk or reduce the side effects from metformin use and that is actually supplementation with vitamin
B12 long-term use with metformin can actually lead to a vitamin b12 deficiency so because of that it can lead to vitamin b12 deficiency signs and symptoms which are very important because they can be irreversible in some cases so a lot of them are going to be neurological like symmetric paresthesias issues with two-point discrimination and issues with propioception
And patients can also experience signs and symptoms of depression as well so metformin can lead to a vitamin b12 deficiency especially with chronic use so i do want to mention here that supplementation with vitamin b12 during metformin use is very important so we can get vitamin b12 from a variety of food sources or from supplements so i want to mention that here
Because we can reduce the risk of vitamin b12 deficiency and reduce the risk of signs and symptoms of vitamin b12 deficiency if you want to learn more about the side effects of metformin use please check out my full lesson on that topic and if you haven’t already please like and subscribe for more lessons like this one thanks so much for watching and hope see you next time
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What To Avoid When Taking Metformin | Drug Interactions | Pharmacology By JJ Medicine
