8 Medications with Surprising Secondary Uses

8 Medications with Surprising Secondary Uses

[ ♪ Intro ] Modern medicine is pretty incredible. Walk into any drug store and you’ll see
shelves of pills and syrups to treat your drippy nose, your rumbly stomach, or your
aching back. The pharmaceutical industry has poured billions
of dollars into coming up with new treatments for everything from the common cold to cancer
— but not every treatment is brand new. Medications that were developed to treat one
condition can end up being useful for seemingly unrelated ailments, which actually involve
similar parts of the body or brain. Here are 8 medications that turned out to
do more than researchers initially thought. First up is dextromethorphan. You might recognize it as the main ingredient
in your favorite over-the-counter cough suppressant. This medication helps ease your hacking, but
it doesn’t work like some cough medicines that loosen mucus in your windpipe. Instead, dextromethorphan acts on your brain. It basically tells your lungs to chill out. It’s actually an opioid derivative, and
we think it binds to and blocks a bunch of different neurotransmitter receptors, like
NMDA and serotonin receptors. That’s why it’s useful for treating other
conditions. Dextromethorphan, combined with another chemical
that keeps it from being broken down as quickly, is actually the only FDA-approved medication
for treating pseudobulbar affect — where a person can’t control episodes of laughing
or crying. It’s usually seen after a stroke or a brain
injury or in neurodegenerative conditions. In a healthy brain, there’s a careful balance
between excitatory signaling and inhibitory signaling — telling cells to fire off a
message or not to fire. Pseudobulbar affect is considered a disinhibition
syndrome, meaning there’s less inhibitory signaling than normal. So the balance is off and there’s too much
firing in the cells that control emotions. Dextromethorphan is thought to help because
it can block NMDA receptors, which reduces excitatory signaling and restores overall
balance. This helps patients better control their emotional
expressions, so when they get the giggles, it’s not because they literally can’t
help it. Dextromethorphan isn’t the only drug that
blocks NMDA receptors. There’s also memantine, a drug that’s
usually used to treat Alzheimer’s disease. Alzheimer’s is really complex, but scientists
think that one of the big problems is something called glutamate toxicity. Glutamate is a neurotransmitter involved in
excitatory signaling in the brain. So when there’s too much excitatory signaling,
a lot of extra glutamate ends up hanging around and binding to receptors. And over time, this overdose can kill neurons. So the logic behind memantine is that blocking
NMDA receptors could reduce glutamate signaling and prevent that toxicity. And it seems to work! Several review papers that looked at multiple
studies showed that it can help with cognitive function and agitation in Alzheimer’s patients. But memantine might also help with other brain
conditions, like obsessive compulsive disorder, or OCD. OCD is fairly common — an estimated 1-3%
of the U.S. population has it. But there aren’t too many medications to
treat the symptoms. These range from persistent anxiety-causing
obsessions about things like germs, to feeling compelled to do certain repetitive actions,
like turning the lights on and off. Recently, scientists have noticed that in
both human and animal studies, changes in glutamate signaling in the brain seem to contribute
to OCD symptoms. So they decided to try drugs that interact
with NMDA receptors to balance things out. And several clinical trials seem to show that
memantine improves symptoms more than a placebo — which is good news for OCD patients who
are struggling to find a treatment that works for them. Addictions can be hard to kick, but scientists
have been working on medications like naltrexone that can help. It’s usually prescribed as part of addiction
treatment for opioids, like heroin. These drugs activate opioid receptors in the
brain, which kicks off the biological processes that trigger feelings of pleasure and reward. Over time, repeated use of the drug can change
signaling in the brain so that someone needs the drug to feel normal, and without the drug
they can’t really function. And that’s when it becomes an addiction. Naltrexone binds to opioid receptors, too
— but instead of activating them, it blocks them. That way, it can keep addictive drugs from
interacting with brain cells as much. It’s also prescribed to help with alcohol
addiction, but it’s not totally clear how this works, since ethanol molecules don’t
bind to opioid receptors. One hypothesis is that when an addicted brain
gets flooded with ethanol, it releases endorphins, which also activate the opioid system and
could reinforce the behavior. And that’s what naltrexone might help stop. Now, naltrexone is also being used to treat
behavioral addictions, like gambling or compulsive hair pulling. This might not seem super surprising — after
all, what works for one addiction should work for another, right? But think about it this way: when someone
takes opioids or drinks alcohol, those substances get in their bloodstream and bind to receptors
in their brain, leading to physical effects and contributing to addiction. Behavioral addictions don’t involve a substance. They’re a result of how a particular behavior
makes a person feel. So naltrexone seems to treat addiction whether
there’s a physical substance or not. And that seems to suggest that endorphins
or opioids binding to opioid receptors activate the same pathways. And the more scientists understand about addiction
and the brain pathways involved, the better we can treat it. The drug sildenafil was originally developed
to treat problems like pulmonary hypertension. That’s where arteries and capillaries in
the lungs and heart get constricted, making it harder for blood to flow properly. So the heart has to work harder to pump, which
can make it weaker over time. Specifically, sildenafil blocks the activity
of an enzyme called phosphodiesterase type 5, or PDE5. PDE5 breaks down another compound that’s
involved in relaxing smooth muscles — the ones that surround blood vessels and some
organs like the intestines. So when PDE5 is active, those muscles contract
and blood vessels get narrower. And blocking the enzyme lets them relax, leading
to more blood flow. During the testing phase of sildenafil, scientists
noticed that it not only affected blood vessels in the lungs — it also affected blood vessels
in the penis, because PDE5 is really active there too. And this meant a bonus side effect: long-lasting
erections. As a result of this … perk, the pharmaceutical
company rebranded the drug as an erectile dysfunction medication and continued research. So sildenafil is now well known as Viagra. There are other hypertension drugs with useful
side effects, too. Like spironolactone, which was developed for
treating high blood pressure and heart failure. This medicine blocks the binding of aldosterone,
a hormone secreted by the adrenal glands right above your kidneys. Aldosterone tells kidney cells to reabsorb
sodium so you don’t pee it out, which helps keep your body’s salt levels balanced. And all those salts are pretty important. They keep your nerves firing, your muscles
functioning, and your fluids balanced — so your cells stay nice and plump without getting
too swollen. But when there’s too much aldosterone, too
much sodium gets absorbed back into the bloodstream. That, in turn, makes more water get reabsorbed,
which means there’s a lot more fluid packed into your blood vessels — causing high blood
pressure. So when spironolactone binds to and blocks
these receptors, aldosterone can’t do as much, and blood pressure goes down. But then doctors noticed that spironolactone
also blocks progesterone and androgen receptors, which opened the door to new possible uses
— like treating hormonal acne. Blocking androgen receptors means androgen
hormones can’t bind. And this can lead to perks like less sebum
— that oily gunk that protects your skin from drying out, but causes zits if there’s
too much of it. But because it blocks androgen hormones like
testosterone, it can have side effects in biosex males — including gynecomastia, which
is the growth of male breast tissue, and reduced fertility. In fact, spironolactone is so effective at
blocking androgens that it can be prescribed along with estrogen for transwomen who choose
to undergo hormone therapy. Propranolol is another drug used to treat
hypertension — but in a different way. It’s a beta blocker, named because they
block beta-adrenergic receptors, which are mostly found in organs like the heart and
kidneys. Propranolol keeps chemicals like epinephrine
and norepinephrine from binding — which you might know by a different name: adrenaline
and noradrenaline. These compounds kick your body into gear,
getting your heart to pump faster, dilating your pupils, and making you more alert. All that “adrenaline rush” stuff. So the main effect of a beta blocker on the
heart is to make it beat slower, lowering blood pressure. But research seems to show that propranolol
might also help with certain kinds of anxiety — though it’s not totally clear how it
works, and the data is spotty. It could be because propranolol reduces the
physiological sensations of high stress — like the sweaty palms and fast breathing that are
also caused by epinephrine signaling. Without those sensations, anxiety levels in
the brain might not spike as much, which could be enough to show some confidence before a
speech or an important interview. And the list of hypertension medications with
useful side effects doesn’t stop there! A drug called minoxidil was developed to open
potassium channels in smooth muscle cells, like the ones that line blood vessels. Opening these channels lets potassium ions
flow through, which sets off a chain reaction that ultimately causes the muscle cells to
relax. And this leads to wider blood vessels and
lower blood pressure. But one of the side effects of minoxidil is
hypertrichosis, which is a fancy way of saying a lot of hair growth. So it’s also a great hair loss treatment. You’ve probably even heard of it before
— as the brand name Rogaine. What’s going on molecularly is a bit of
a mystery. But some researchers think that because minoxidil
can cause more blood flow, this provides more nutrients to the hair follicles and can encourage
new cell growth. What we do know is that minoxidil seems to
shorten the length of telogen, the resting phase of the hair growth cycle. See, every strand of your hair isn’t always
growing. Hair follicles chill in telogen for a few
months before kicking back into anagen, the growing phase where new hairs are formed. So by shortening telogen and jumpstarting
anagen, minoxidil can encourage new hair to grow before it would have on its own. And that’s not the only medication that
surprisingly affects hair. Bimatoprost is a drug that’s usually prescribed
to treat glaucoma. Glaucoma is condition where a buildup of fluid
increases the pressure inside someone’s eye, to the point of damaging the optic nerve. If it’s not treated, it can lead to loss
of sight and even total blindness. Bimatoprost is a synthetic prostaglandin,
a hormone-like chemical found throughout the body that helps the eye drain extra fluid,
getting the pressure closer to normal. It’s not totally clear how bimatoprost interacts
with certain eye tissue to activate pathways involved in drainage, but it seems to work. And it comes in an eyedropper form, making
it easy for patients to use. But once again, doctors noticed a weird side
effect: patients using bimatoprost found that their eyelashes were growing longer than normal. And after some more research, it’s officially
FDA-approved for cosmetic use, and marketed as Latisse. It’s not entirely clear how bimatoprost
encourages eyelash growth, either. But it seems like it encourages eyelash follicles
to jump back into the anagen phase prematurely, like minoxidil. And it even seems to stimulate melanin production
in pigment-producing cells, which leads to longer, darker, fuller eyelashes. All of these medications were initially developed
with one goal in mind, but we learned a lot from studying all of their effects. These discoveries give doctors and patients
more options for treating medical conditions… and for fixing their cosmetic woes. So we can’t really knock a treatment until
we’ve tried it — with peer-reviewed clinical trials, of course. Thanks for watching this episode of SciShow,
which is produced by Complexly — a group of people who believe the more we understand
about ourselves and the world, the better. If you want to learn more about human health
and medicine, check out one of our other channels, Healthcare Triage, at youtube.com/healthcaretriage. [ ♪ Outro ]


  1. Yay, you mentioned Spironolactone! And you also mentioned the reason I take it. It is a wonderful medication, I’ve also noticed that I don’t get many breakouts, anywhere on my body….

    Though, my skin is super dried out because of it. But, I do not care, I am taking a journey I should have started years ago.

  2. Wellbutrin and Zyban. They are both the same drug. Zyban was/is sold as a quit smoking aid. Wellbutrin is prescribed for depression. No big deal except they charged far more for Zyban. I doubt Zyban is prescribed much anymore though. Also many drugs get very slight changes made that really have little to no change in effect and then get sold again under a new name for top dollar while the older version can be bought generic. Pharmaceutical companies are the biggest scammers in the world.

  3. I take propranolol for both my high heart rate and extreme anxiety (along with other medications for anxiety) and I have to say it works very well for both

  4. Before I watch: I take Prasosin, a blood pressure medication that surprised doctors when it became apparent that people with severe PTSD who took it just stopped having nightmares. I also take hydroxychloroquine, a malaria medication. I dont have malaria but I do have sjogrens and RA.

  5. What about the drug originally used to fight protozoa parasite infection, now used as a "behavior modifier" for people with alcohol abuse problems… Antabuse

  6. Adderall was originally used to keep pilots awake, and as a weight loss drug. Now, it's used to reduce symptoms of ADHD. Just be careful with it- it can make existing heart problems worse

  7. Montelukast = asthma medication but can be used as a mast cell stabilizer for people like me with a mast cell disorder , without montelukast I believe I’d be dead by now

  8. Scientists are now finding that there is one treatment that addresses prevents and even cures multiple maladies it’s called the keto diet. It seems most of these illnesses are caused or worsened by the crap we eat especially sugar and polyunsaturated oils, it’s almost as if the modern diet was a creation of drug companies so they could sell lots of useless treatments to illnesses that didn’t exist before they told us what a healthy diet was.

  9. Naltrexone can also be custom formulated into a low dose form and used to treat a wide range of issues. It seems to work on some kinds of pain, which is awesome as it’s far less harsh on the body than stronger drugs like gabapentin and opiates. It’s also being used with some great success in patients with issues like CFS/ME and Fibro. I know several people on it for post-Lyme Disease Syndrome, ME, fibro and/or arthritis who swear by it.

  10. I use propranolol for anxiety, and I personally have found it to work incredibly well. It doesn't stop me from feeling nervous in my head, but I don't get a fuzzy memory, flushed face/neck, sweaty palms, or shaking. I recommend it for people hoping to stop the physical symptoms of anxiety.

  11. people always think im a bit nuts but ive always like dxm, smoke a littel weed with it man and im communing with tree spirits in my backyard with my dog.

  12. I was gonna guess DXM was gonna be in this, wasn't gonna guess it was gonna be the first one. Gotta love that crazy ass drug… robotrippin' adventures..

  13. As someone with ocd, a hair pulling disorder (trichotillomania) and no eyelashes as a result, theres now three drugs I need to try 😂😂

  14. "more effective than placebo" … no disrespect and I really enjoy the videos (honestly, you guys and gals rock) … but wouldn't 50% of completely ineffective treatments be statistically "better" than the average placebo?

  15. Biosex though really your a science show, get a grip chopping and dicing has never sucessfully made a man carry a baby or a woman inpregnate a woman, facts are what you deal in not feelings and dreams

  16. It's funny how you talk about Spiro and Minoxidil in the same video. One is used by transwomen, the other by transmen. I prefer using biotin for my hair growth because too much Mino can lead to hair loss and it's also lethal to kitties.

    Biotin helps in the time being.

    Spiro: titty Skittles
    Biotin: moustache m&m's

  17. I was prescribed propanalol for headaches. It helped some, but after about 3 weeks, my ptsd was completely GONE! Later, I read in a science magazine that propanalol was being tested on veterans with ptsd. I know first-hand: it works!

  18. The mind and the body feedback on one another in a loop. It seems obvious to me that treating symptoms in the body would affect how the mind responds and vice-versa.

  19. I love how Viagra was used as a heart med & now marketed as a erectile dysfunction med. What some forget is the too much can cause a heart attack

  20. I'm surprised Prazosin/Minipres was not mentioned. A hypertension pill that also works as a nightmare medication should be on the list!

  21. There's a potent anti-epileptic called Pregabalin (brand name Lyrica ), which is basically a modified version of the neurotransmitter GABA ( Gamma-Aminobutyric Acid ), which acts as a neural suppressant.

    It's secondary use is for the treatment of severe Neuropathic Pain , such as Trigeminal Neuralgia , Restless Legs Syndrome & Fibromyalgia .

    There's also anecdotal evidence that it is effective for Generalized Anxiety Disorder .

  22. Another fun side effect of propranolol is that it makes people less racist (at least in terms of performance on implicit bias tests).


  23. Propanalol also prevents nightmares in some patients (including myself), though that probably is related to its anti-anxiety properties.

  24. Djust recently started taking propanolol, not for brood pressure, but to prevent tremors in hands – has been verr effective, big improvement.

  25. To add to the list:

    Glucagon – used for low blood sugar, also treats beta blocker and calcium channel overdose

    Insulin and albuterol – in addition to high blood sugar and asthma/copd treats hyperkalemia (high potassium)

    Ibuprofen – sometimes given IV to neonates with PDA (patent ductus arteriosus)

    Gabapentin – for seizures also used for pain

    Several antidepressants also used for pain

    Botox – also used for neurological disorders

    Metformin – in addition to diabetes also used to treat PCOS and fertility issues

    Metoclopramide – acid reflux also used to treat insufficient milk production

    Quinidine – antimalarial also used as an anti arrhythmia med

    Erythromycin and azithromycin – antibiotic also used for gut motility

    Naloxone – Narcan used for opioid rescue when taken orally can be used for narcotic induced constipation

    Fleet enema – my personal favorite. This enema is mainly sodium phosphate and when taken orally can be used for phosphate replacement especially when IV sodium phosphate is on shortage.

    Intralipids – for IV nutrition also used for anesthesia rescue

    Bupropion – antidepressant for smoking cessation

    Statins – anticholesterol medication like Lipitor used as an anti inflammatory, immunomodulator and possible antibiotic.

  26. This is a disaster. Whatever doctor came up with the statistics of the percentage of people with OCD in the us is clearly a madman. He is torturing the hell out of them by listing 2 odd numbers. And you.. why the hell didn't you say around 2%? You offended Monk! MONK!

  27. Naltrexone can kill you if you drink(and you turn red, have a hard time breathing) that's how it works. Plus it's actually chemically addictive. I got headaches and anxiety when I didn't take one…

  28. Naltrexone is amazing. I am a terrible alcoholic and this drug has helped me top finally get sober. It's almost a miracle drug

  29. Naltrexone is even more toxic than heroin , also it doesn't work , people still use opiods even with the treatment, no one is the same genetically and some people do not methalize medication the same way , also if you have MTHFR ' MEDICATION ' CAN BE LETHAL ESPECIALLY METALOSIS LUPUS OR LACK OF SEROTONIN (WHICH BY THE WAY IS FORMED IN THE STOMACH NOT THE BRAIN ) WHICHY FIRST QUESTION IS WHY ISN'T FOOD AND EXERCISE AND NATURAL THERAPY AND NATUROPATHY USED FIRST BEFORE BEING USED AS A GUINEA PIG BY EVIL GREEDY PHARMACEUTICAL COMPANIES AND MURDERING GOVERNMENT?

  30. i have a friend who was prescribed naltrexone for a self harm addiction. unfortunately the drug also numbs pain so it didnt work out too well

  31. Really growing weary of that same old lazy excuse for refusing to even try to learn.
    "It's not clear how it works, but it does."
    WHY is it not clear?
    Because literally no one has ever bothered to LEARN how, that's why.

    They simply stop looking into it once they get so many positive results.
    There is absolutely no logical reasoning for not knowing how these chemicals function by now.
    Must be distracted by that sales woman in a skirt selling the chemicals doctors rely 100% upon.

  32. 1:15 Does anyone remember that bit on Best of the worst wherein mike started laughing loudly at nothing, despite mike rarely laughing? What if it was something like that?

  33. Mercaptopurine is a chemo therapy drug with seroius side effects of weaken immune system and potential liver failure. However, it only supress a very specific part of the immune system which is extremely useful to control certain auto immume disease. Those people take lower dosage which avoid the hair loss problem.

  34. Propranolol also gets used to treat migraines. An entire episode could probably be done on drugs used to treat migraines that are drugs originally intended as anti seizure medications or antidepressants or blood pressure medications or Botox.

  35. I'm really sad Topamax wasn't mentioned considering it has about 10 different uses that range from anti-seizure, mood stabilizer, treatment for nerve pain, migraine prevention, treatment for PTSD flashbacks, and I feel like I'm reading about a new use for it everyday.

  36. wow, i clicked "like" right from 7999 to 8000, what are the odds? xD
    nice stuff as always keep it up! ty for everything!

  37. I take Vyvanse, officially for adhd but I think I have BED as well cause I stopped binge eating, had a much easier time just saying no to junk food in general and started losing weight.

  38. The aspirine use to reduce chance to have hard attack (it have an outer use so important in person with height risk

  39. Anxiety is more complex than you or most doctors have any idea… I have been diagnosed it, and it not the first related problem I was diagnosed with… Anxiety causes countless other problems that doctors tried to treated first (depression when young, and high blood pressure recently). The problem is the anxiety, not it's secondary effects. Beta blockers help a ton!

    Feel free to turn #3 in to an entire episode! 🙂

  40. The Pharmaceutical Industry is responsible for the DSM, creating factitious mental illnesses & dangerous drugs under the guise of treating medical conditions.

    I'm not saying mental health conditions are not real, but that they invent drugs, then claim they've found a miracle treatment.

    That's why it's almost impossible to find balanced research on efficacy, subjects are cherry picked to falsify or exaggerate efficacy.

    Addiction is increasingly proven to be caused by a combination of genes & exposure to stress & trauma.

    Dr Peter Breggin & others have successfully taken these issues to court, proving many psychiatric drugs can do more harm than good, especially SSRIs & Antipsychotic drugs.

    I was dubious about this until I had first hand experience of this.

    There is no one size fits all drug therapy that works equally for everyone.

    Those of us on the Autism Spectrum are particularly sensitive to side effects that are worse than the cause of the problem that gets us prescribed drugs.

  41. In addition to what was mentioned in the video, propranolol is also a highly effective treatment for many people like myself who have migraines or Essential Tremor.

  42. Propranolol can also help with Essential Tremor (especially if it's aggravated by anxiety…) I have tremors in my right hand and my jaw, and have propranolol to take if it gets bad on a particular day.

  43. Yeah, I've heard about some cases where some guys took medication and it made them get their ears pierced and look like African pygmies.

  44. Spironolactone sucks as an anti androgen, it won't reduce anything masculine yet alone stop erections but it will put peach fuzz on your cheeks plus stuff your completion because the dosage used is massive for the drug making it very dangerous seriously dangerous.

  45. I’m on prazosin, otherwise known as minipress. It’s a medication for high blood pressure, but I don’t have high blood pressure. It helps with my PTSD nightmares 🤷🏻‍♂️

  46. I took Naltrexone to help me stop SH and everyone thought I was taking opioids. It was SO annoying and embarrassing

  47. Yeah modern medicine is incredible. Infested with scavengers who want nothing more than to reap every last dollar from an ailing populace. You think they care about helping anyone?

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