Steph’s Note: Remember back to before pharmacy school? You were raging sick, snotty nose running, couldn’t think straight, and you hit up the corner pharmacy for some relief. You zombie-walked your way through the front doors, past the aisles of makeup and clearance Halloween candy. Then, crap. You hit the cough and cold aisle. Not just a small section. An entire aisle dedicated to confusing your poor, congested brain. Heck, they threw 3 shelves of acetaminophen products at you too! As a non-pharmacy person, that’s a lot. Even as a pharmacy student, that’s a LOT. Trying to learn all of those over the counter (OTC) products is kinda overwhelming.

Let me start off by saying that, our author, Tiffany Nguyen (a PY4 at the VCU School of Pharmacy in Richmond, VA), won’t go over all of the different OTC options in this post. Only because, as you can imagine, it would actually turn into a tl;dr. But what she will dive into are the different products for the cold/cough and well… bowel-related issues.

Of note, for the cold and cough section, she will be mentioning some products that were nicely explained here. So if you need a refresher on decongestants and antihistamines, start over there, and then come back for more! Take it away, Tiffany!

Therapies for Cold and Cough

So let’s tackle cold and cough first - mostly because, at the time I’m writing this, it’s the beginning of the flu season and the peak time for catching the common cold.

So here’s your PSA for the day, PLEASE go get your flu shot. In the words of Nike, just do it.

The common cold can result from any of more than 200 viruses, which includes common rhinoviruses and coronaviruses. It is transmitted through the air on respiratory droplets or from mucus secretions.

So wash your hands. Sneeze into an elbow or (better yet) a tissue! It might actually help prevent you or others from getting sick. It takes about 2-4 days for symptoms to develop and will hopefully (fingers crossed) just last 7-14 days. The peak time for catching the common cold is September-October and early Spring.

So how the common cold works is that the virus du jour binds to the cells in your nose or nasopharynx (right past your nasal cavity), replicates, and spreads. The cells that have been affected send out signals and activate inflammatory mediators. And then hopefully your body does its job to kick some virus butt.

To help your body do that, let’s chat some OTCs. First, let’s tackle a couple of natural products (because it wouldn't be a good OTC article without mentioning at least a couple!).

Zinc

Yes, that’s right, one and the same metal as that on the periodic table. It doesn’t have much data for the common cold, but it still shows up in products like Zicam. I’m going to go out on a limb and say it’s hard to take this product correctly. Why is that, you ask? Patients have to take it within the first 24 hours of symptom onset and then every 2 hours while they are awake.

Now let’s be real here. It’s hard enough to get a patient to a medication 3 times a day, let alone 12 times a day! So you see my hesitation.

The only way I could see this possibly working is if the patient uses the lozenge formulation. (I can’t have been the only one at one time or another who’s eaten cough drops or lozenges like candy!)

Even though lozenges may be a little easier to do every 2 hours, they can also cause mouth irritation, a metallic taste, and even nausea. Also important to note is that patients should not use these zinc lozenges for more than 5-7 days because they can lead to copper deficiency. So zinc products aren’t necessarily all they’re cracked up to be.

Fun fact #1: Zinc used to be in some nasal cold relief products; however, because it caused some loss of the sense of smell, it was removed from the market. (And you thought being congested was bad…)

Echinacea

Echinacea is an herb that is a genus of the daisy family (hello throwback to taxonomic rankings), and it gained some popularity for possibly shortening the length and severity of the common cold. Unfortunately, the data just haven’t backed this idea. Whether it’s due to the wide variety of types of Echinacea available, the different parts of the plant used in products (root vs herb vs both), the different preparation methods, or because it just doesn’t do anything at all, the reported benefits just have not panned out in the numbers.

It’s also important to note that it is considered a supplement by the FDA according to the 1994 DSHEA law, meaning products containing Echinacea are not regulated to the same extent as medications. As this 2003 JAMA article notes, what’s on the label of Echinacea products may or may not be what’s in the bottle! Some of these herbal products are also mixed with other supplements, so be very wary of drug interactions.

If patients are insistent upon trying Echinacea to alleviate their cold symptoms, Echinacea is reportedly time sensitive. Patients should begin taking within 24-48 hours of symptom onset. Important note: this is not recommended for anyone who has autoimmune disorders or immunosuppression since it can suppress the immune system even further.

Ascorbic Acid

I know, I know, you’re all thinking, “Fiiiiinally!” The classic natural product for cough and cold. Ascorbic acid, aka vitamin C, has some evidence for decreasing the duration of a cold by 1-1.5 days. But importantly, its effects are mostly demonstrated with at least 2 grams per day. That’s a lotta lotta vitamin C, and honestly, your body can only absorb so much at one time. Since it’s a water soluble vitamin, excess is excreted in the urine, but taking large doses (more than 4 grams per day) can lead to other problems like diarrhea and kidney stones (especially in men).

All of these natural products can be as expensive as the next couple of products we’re going to discuss, but they don’t really have the data to prove they’ll actually work. So, using any of them definitely comes with the caution of “use at your own risk”.

So now that we’ve gone through the natural options, let’s walk a little further down that cold and cough aisle. There are liquids and capsules and tablets, oh my!

Pro Tip: ALWAYS look at the back to check out the active ingredient!

Anyways, while wandering the aisle, you cough, and it feels like you’re hacking up half a lung. As much as you don’t want to have to think, you have to assess your cough. There are two types of coughs: a productive cough (where you can feel that phlegm moving) or nonproductive cough (dry).

Let’s first pretend that it’s a productive cough.

Guaifenesin

In this case, reach for the expectorant. Expectorants work by thinning out the phlegm in the lower respiratory tract and increasing secretions in your upper respiratory tract to move that phlegm out. It’s important for patients to take this with plenty of fluid, which can help to loosen and thin phlegm.

Guaifenesin ER tablets should not be used in children less than 12 years old. Also depending on the formulation, they can have phenylalanine present. (Patients with phenylketonuria (PKU) have to avoid phenylalanine.)

Scenario 2, we’ll move on to the dry cough now. If you have a dry, hacking cough that is unproductive, cough suppressants are for you!

Dextromethorphan

This is a non-opioid, non-controlled cough suppressant agent without the addictive properties found with other cough meds.

Dextromethorphan is contraindicated if taken within 14 days of monoamine oxidase inhibitors (MAOI). The MAOI will enhance the serotonergic effects of dextromethorphan and can even cause serotonin syndrome. Dextromethorphan also has additive central nervous system depression when used with alcohol, antihistamines, and psychotropic medications.

Interestingly, there are many OTC products that contain both guaifenesin and dextromethorphan. Seems a little counterproductive to have an expectorant in with a cough suppressant, right? Like they might work against each other?

Confusing, but I suppose if the patient is coughing so much that sleep isn’t possible… maybe it’s worth a try.

Fun fact #2: Dextromethorphan is an N-methyl-D-aspartate (NMDA) receptor blocker at high doses. If you remember anything about illicit drugs, this means it can have effects similar to PCP, including hallucinations and euphoria. The practice of taking too much dextromethorphan is known as “robo-tripping” due to abuse with dextromethorphan-containing Robitussin. This is also why many states have enacted an age restriction on the purchase of dextromethorphan products (often ~18 years old).

Codeine

Although increasingly more difficult to obtain from retail pharmacies, another cough suppressant is codeine. This is a C-V schedule controlled substance, and if it is a liquid, there cannot be more than 200 mg of codeine in 100 mL to qualify as OTC.

Fun fact #3: Codeine is commonly abused with the anti-emetic promethazine because the combination produces a high/euphoric effect. It’s also called purple drank or lean.

In summary, there are quite a few active ingredients that can help your cold and cough, but they also happen to come with a lot of warnings, including for abuse.

The next class of cough and cold remedies also happens to have a drug that is misused. It even made it to the small screen (which BTW, such a good show! But not for the faint of heart or those who are underage). Any guesses? HINT —>

You got it. Decongestants. Decongestants help patients to breathe more easily by reducing nasal and sinus congestion. For mechanisms, check out this post.

Pro Tip #2: if you see a product with a capital “D” at the end of the name, this often refers to the presence of a decongestant, specifically pseudoephedrine (e.g., Claritin D).

If you didn’t get my reference before with Breaking Bad and their “Blue Sky”, it was about using pseudoephedrine to make crystal meth. This is the reason people have to essentially register when they buy any product containing pseudoephedrine, and it’s also why there’s a limit on quantity purchased.

The federal Combat Methamphetamine Epidemic Act of 2005 mandates that a person can buy no more than 3.6 grams of pseudoephedrine in 24 hours and no more than 9 grams in 30 days (3-6-9 is how I remember it). This act actually includes not only pseudoephedrine but also ephedrine and phenylpropanolamine.

Ages in years; SE = side effects; CV = cardiovascular; HA = headache

Another more localized decongestant option is oxymetazoline, aka Afrin. Serious counseling point: patients should not use oxymetazoline for more than 3 days at a time due to the possibility of dependence and consequent rebound congestion when they actually do stop using it. This is where the saying “less is more” definitely applies.

A third option to help with the symptoms of congestion is an antihistamine. Antihistamines help with runny noses and sneezing due to their anticholinergic effects. Remember those effects by the rhyme about Alice in Wonderland: hot as a hare, red as a beet, dry as a bone, blind as a bat, and mad as a hatter. (Alternatively, there’s the good old favorite: can’t see, can’t spit, can’t pee, can’t s**t.) That is, they dry patients up!

First generation antihistamines like diphenhydramine, chlorpheniramine, and brompheniramine can cause CNS depression and sedation; on the other hand, they can paradoxically cause excitation in pediatric patients. They are contraindicated in newborns and premature infants given multiple reports of infant death, and they should absolutely not be used to make babies and children go to sleep.

Caution is also warranted in breastfeeding women, patients with acute asthma, and those who use MAOIs (monoamine oxidase inhibitors like selegiline). The elderly should also be cautious when using these medications due to their strong anticholinergic effects and effects on glaucoma (Beers criteria!).

Fun (finally not about illicit drug use) fact #4: Diphenhydramine also has some antitussive properties so it may be a good two-in-one if patients aren’t part of those groups listed above.

The second generation antihistamines, including cetirizine, loratadine, and fexofenadine, come with their own caveats. They can still cause CNS depression and sedation, especially if used with other sedating agents. Levocetirizine is contraindicated in patients with end stage renal disease (CrCl <10 mL/min) or on hemodialysis. It also shouldn’t be used in infants and children 6 months to 11 years old with renal impairment.

Fexofenadine should not be taken with any fruit juices, including grapefruit, apple, or orange. These juices can decrease bioavailability of fexofenadine by about a third! Co-administration with aluminum or magnesium-containing products like some antacids will also decrease absorption of fexofenadine.

Women who are pregnant (congratulations :D) can use loratadine and cetirizine.

So hopefully this information can help you determine which products are best for your patients with cough and cold. Still quite a lot of stuff to sift through, but hey, you got through it, and hopefully you (or whoever is wandering the pharmacy aisles) feels better soon!

Therapies for Constipation and Diarrhea

Time to shift gears a little to a different aisle in the pharmacy.

If you’re eating right now, I promise you’ll be alright. The pictures won’t be like THAT.

Diarrhea and constipation are two extremes that can be caused by diet, drugs, different medical conditions, or any/all of the above. It’s complicated.

Let’s start with diarrhea. As long as the diarrhea isn’t so severe as to cause dehydration (please see a doctor) and it’s not due to a GI infection (e.g., Clostridium dificile colitis, again please see a doctor), it may be helpful to call on some OTC friends to slow it down. There are two OTC anti-diarrheal options: bismuth subsalicylate (Pepto Bismol) and loperamide (Immodium).

Bismuth subsalicylate works both by limiting gut secretions (anti-secretory) and by attacking gut pathogens (antimicrobial). As an opioid receptor agonist in the gut, loperamide slows down the intestines to allow water to be reabsorbed, which leads to more formed stools.

BBW = black box warning; CI = contraindications

One of the most important counseling points when discussing diarrhea with your patients is to remind them to replete their fluids and electrolytes, especially in the elderly and children. For those two populations, they are more likely to not be able to bounce back as easily as an adult would. However, they are also two populations for whom that fluid repletion isn’t always straightforward. What if the elderly patient has kidney disease or heart failure? How much fluid can they handle? What will happen to their fluid status or electrolyte balance if you tell them to drink Gatorade??

Sorry, Gandalf. Sometimes a pharmacist gotta tap out and defer to the physician. (Image)

Might be a good referral moment to their primary care doctor. Just sayin.

So then let’s go to the flip side. Your patient with previously loose stools returns to the pharmacy and says she now hasn’t had a bowel movement in almost 4 days after a couple doses of loperamide (and she’s used to going every day). She’s tried eating some additional vegetables and has been sure to walk around the block every day without bathroom success.

From the 2013 American Gastroenterological Association guidelines, gradually increasing fiber with or without an osmotic agent or a stool softener would be first-line therapy. Fiber products include psyllium, which can help improve cholesterol and blood sugar levels (bonus!). The downside to increasing fiber intake? Patients have to also consume more liquid with these products, which might cause problems for some.

Since our patient reports already increasing her dietary fiber intake, it seems as though we may have to go to plan B.

You pull a bottle off the shelf thinking it’s just docusate, which is a surfactant stool softener. This means it allows the water and fat contained in the stool to mix better, which ultimately leads to softer stool. It’s the “mush” of the bowel regimen team.

Being a good pharmacy intern, you check the label on the bottle for additional information. You notice that there is in fact another active ingredient on there. The other medication is senna, which is a stimulant laxative, meaning it actually stimulates the body to expel stool. This is the “push” of the bowel regimen team. Senna takes about 8-10 hours to work, so taking it right before bed usually allows for nice morning relief.

You discuss the option of combination docusate + senna with your patient, but she says, “I can’t do it! Another 10 hours will feel like 10 years!”

So you reach for another stimulant option - bisacodyl. It is available both as tablets and suppositories. It tends to work more quickly than senna, but it’s also a little more aggressive. So it’s a good idea to warn patients to stay within reach of a bathroom.

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Glycerin suppositories are an osmotic option that also works pretty quickly (within half an hour). So if patients just can’t wait for the oral agents like docusate, senna, or polyethylene glycol to work (understandable), there are some from-the-bottom options for quicker relief.

A good time to give osmotics is 30 minutes after a meal when the stomach is already churning, but really, any other time works as well.

Remember, there is a pretty big window of when these drugs might work if taken orally. So depending on when you tell patients to take these, they might be waking up in the middle of the night for a potty run. (I’m looking at you magnesium hydroxide - why would anyone advise taking this right before bed unless they are having a procedure the next day?!?)

Final fun fact #5: Lactulose is used for hepatic encephalopathy as well. Win-win.

There you go. My semi-condensed version of what you could use for relief of cold and cough, diarrhea, and constipation. Hopefully after all of this, you have a better idea of which products to use or recommend when you come across one of these problems. It’s definitely one of those “take a breath, break it down, and you’ll get through it” moments.

OTC Take Home Points

Check labels to ensure you aren’t duplicating ingredients between products
Be wary of herbals and supplements given the possibility of drug interactions, indeterminate ingredients, and unclear efficacy
Discuss symptoms with patients to more accurately identify useful active ingredient options (don’t fall for the *coughcoughmucinexdmcoughcough*)
When giving OTC advice to patients, be sure to take into consideration the OTC product labeling, even if a product is also available as a prescription medication
- Example: Esomeprazole should only be used for 2 weeks according to OTC labels, even though of course we do use it longer as a prescription. This is meant to encourage people to follow up with providers if they have not improved to see if there’s something more serious occurring.

A Quick Guide to the Most Commonly Used OTC Meds