Imodium A-D vs. Pepto-Bismol

The first thing you need to know is that there are two types of medications: those which contain one or more active ingredients (such as antibiotics) and those which do not (such as over-the-counter cold medicines). Some drugs are used for both purposes; others only serve one purpose. For example, acetaminophen is used primarily for pain relief but may also be taken internally to treat fever, nausea, vomiting, and other symptoms associated with infectious diseases such as the common cold.

Phenylephrine (also known as epinephrine), a drug commonly used to treat high blood pressure, is also sometimes prescribed for the treatment of some allergic reactions. However, phenylephrine can cause severe side effects if given intravenously because it causes rapid heart rate and increased blood pressure. Phenylephrine is available without a prescription only under brand names like Norco® and Preven®.

Phenylephrine is often used in combination with another medication called dipyrone. Dipyrone is a synthetic version of the hormone prolactin. Prolactin stimulates milk production in women during pregnancy and lactation. When combined with phenylephrine, the result is a powerful diuretic effect that can lead to dehydration and electrolyte imbalance. These effects can cause significant problems when combined with diarrhea caused by either peptic ulcer disease or peptic ulcers themselves.

The combination of phenylephrine and dipyrone may also worsen symptoms in patients suffering from pheochromocytoma, a rare tumor of the adrenal glands that causes anxiety, headaches, high blood pressure, and palpitations. Patients with pheochromocytoma often have impaired kidney function because the tumor produces large amounts of adrenaline. The combination of dipyrone and phenylephrine can trigger a potentially fatal exaggerated response in these patients.

When you start any new medication, whether it’s an antibiotic for strep throat or an over-the-counter pain reliever, be sure to let your doctor know. Medications that seem completely unrelated can interact in ways that affect the body. Some of these drug interactions can be dangerous or even deadly. For example, lots of people use acetaminophen to reduce fever and pain caused by a cold or the flu. However, if you are taking a prescription blood-thinner such as warfarin (Coumadin®), simply swallowing the wrong pill could prove fatal.

Make sure that you tell your doctor about any and all medications that you are taking or considering taking. While most people take only one or two different types of medication in any given day, you may be taking five or more. Many people use several different medicines on a daily basis and don’t even realize it.

Acetylsalicylic acid (aspirin)

Acetazolamide (Diamox)

Acetohydroxamic acid (AHA)

Aclidinium (Tuzistra®)

Adalimumab (Humira®)

Adapalene (Differin®)

Amphetamine (Benzedrine)

Azapropazone (Acephen®, Para-Aminophen®)

Benzoyl peroxide (PanOxyl®, Neutrogena®, Oxy®, Benzoic Acid)

Brompheniramine (Dimetapp®, Bromfed®, Piriton®)

Carbamazepine (Tegretol®)

Chlorpromazine (Thorazine®)

Clemastine fumarate (Tavist®)

Clobetasol propionate (Dermovate®, Temovate®)

Clorpresol (Cormax®, Cormoran®)

Codeine phosphate (Robitussin AC®, Roxicet®, Tylenol #3®)

Cyproheptadine (Periactin®, Cyprostatron®)

Cyclandelate (Cyclogyl-R®, Potassium Cyclamate)

Desloratadine (Clarinex®)

Diazepam (Valium®)

Donepezil (Aricept®)

Dorzolamide (Trusopt®)

Esomeprazole (Nexium®)

Fluticasone propionate (Flonase®, Flovent®, Cutivate®)

Glimepiride (Amaryl®)

Glipizide (Glucotrol®)

Glyburide (DiaBeta®, Micronase®)

Ibuprofen (Advil®, Motrin IB®, Nuprin®)

Imipramine (Tofranil®)

Ipratropium bromide (Atrovent®)

Lansoprazole (Prevacid®)

Loratadine (Claritin®)

Meloxicam (Mobic®)

Methotrexate (Rheumatrex®, Trexall®)

Morphine (MS Contin®, Kadian®, MSIR®, Apo-Morphine)

Nadroparin (Nadroparine®, Lantic®)

Naproxen (Aleve®, Naprosyn®)

Nifedipine (Adalat®, Procardia XL®)

Orlistat (Alli®, Xenical®)

Papaverine (Pavabid®, Pavalin®)

Pravastatin (Pravachol®)

Prednisone (Deltasone®, Liquid Pred®, Meticorten®)

Propantheline bromide (Pro-Banthine®)

Salbutamol (Ventolin®, Proventil®)

Salsalate (Amigesic®, Disalcid®)

Semapimod (AVE0010)

Simeprevir (Olysio®)

Sodium bicarbonate (Bikalit®, Eskazole®, Basac®)

Sparfloxacin (Zagam®)

Sunitinib (Sutent®)

Tacrolimus (Prograf®, also immunosuppressants)

Tamsulosin (Flomax®, Flomaxtra®)

Tobramycin (Tobrex®, Nebcin®)

Trabectedin (Yondelis®)

Vitamin E (Vit. E)

Zafirlukast (Accolate®)

Zileuton (Zyflo®, Zyflo CR®)

Zolpidem (Ambien®, Intermezzo®, Edluar®, Zolt™)

Zopiclone (Imovane®, Lunesta®, Zimovane®)

In addition to the above, be sure to let your medical team know if you are taking any of the following:

Amiodarone (Cordarone®, Pacerone®)

Drugs that dilate blood vessels

Following is a list of some common drugs that may increase the risk of bleeding when taken with clopidogrel.

Take with caution and tell your doctor if you are taking any of the following:

Acenocoumarol (Sintrom®, Seinok®)

Alprostadil (Caverjet®, Edex®)

Ammonia (household cleaners)

Antibiotics (Clindamycin, Tetracycline)

Antidepressants (Phenelzine, Isocarboxazid, Tranylcypromine, Selegiline)

Anti-inflammatory (Diclofenac, Ibuprofen, Indomethacin)

Antipsychotics (Chlorpromazine, Trifluoperazine)

Aspirin (Bayer®, Empirin®)

Caffeine (Coca-Cola®, Coke®, Pepsi®, NoDoz®, Vivarin®)

Calcium channel blockers (Nifedipine, Amlodipine, Norvasc®)

Sources & references used in this article:

Comparative efficacy of loperamide hydrocholoride and bismuth subsalicylate in the management of acute diarrhea by HL Dupont, JF Sanchez, CD Ericcson… – The American journal of …, 1990 – Elsevier

Self‐reported description of diarrhea among military populations in operations Iraqi Freedom and Enduring Freedom by SD Putnam, JW Sanders, RW Frenck… – Journal of travel …, 2006 –

Medications for the prevention and treatment of travellers’ diarrhea by DN Taylor, DH Hamer, DR Shlim – Journal of travel medicine, 2017 –

West Nile Incidence on the Rise, CDC Reports by RS JEFFERSON – Pediatric News, 2006 – …

Use of Proprietary Names by Prescribers When Prescribing Over-the-Counter (OTC) Drug Products by CM Tu – Therapeutic innovation & regulatory science, 2019 – Springer

Prevention and treatment of traveler’s diarrhea by G Juckett – American Family Physician, 1999 –

Traveler’s Diarrhea in Athletes by P Grantham – The Physician and sportsmedicine, 1983 – Taylor & Francis

Travelers’ Diarrhea, the Science of ‘Montezuma’s Revenge’ by F Blank – Food on the Move: Proceedings of the Oxford …, 1997 –