The Truth About Over-The-Counter Cold, Flu and Pain Medications

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The Truth About Over-The-Counter Cold, Flu and Pain Medications

The Truth About Over-The-Counter Cold, Flu and Pain Medications

Colds and flu, headaches, pain and allergies – these are some of the most common conditions many people experience on a daily basis. While these problems are seldom serious, you don’t want to spend money on a doctor’s visit when you can just pop over to the pharmacy for an over-the-counter (OTC) remedy. It will save you time, money and is just too convenient not to do.

The Consumer Healthcare Products Association (CHPA) estimates that the average American household will spend $338 per year on OTC medications, while taking 26 trips a year to purchase them, compared to an average three trips to a doctor.1 It is also estimated that most people, about 83%, will first try an OTC product for a minor ailment before deciding to see a doctor.1 For every dollar spend on an OTC medication, the U.S. healthcare system actually saves seven dollars.1

An OTC product can be described as a medicine that is acquired without the need for a prescription from a doctor. These medicines can be given by a pharmacist to relieve the symptoms of minor ailments.2 Some OTC medications may require a prescription if they are needed in higher dosages than is available in OTC formulations.

Some of the most common conditions that can be treated by a quick trip to the pharmacy and an OTC product include:2

  • Headaches
  • Minor aches
  • Minor pain
  • Fever
  • Diarrhea
  • Coughing
  • Cold and flu symptoms
  • Allergies
  • Dry, red or allergic eyes
  • Stomach pains and cramps
  • Sore throat
  • Minor skin irritations
  • Constipation

Though most OTC medications are regarded by the public as ‘safe’, it does not necessarily mean that they are without side-effects. In fact, every medicine has a side-effect profile. It is just a matter of the benefit outweighing the risk.2 OTC medications can also interact with other chronic medications while some may aggravate a chronic condition without the person even being aware.2

Some of the most common issues with OTC medication usage include:3

  • Subtle overdosing by the patient without realizing
  • Chronic use of OTC medications only meant to be used as acute
  • Interactions with chronic medications
  • Can affect chronic conditions like blood pressure, diabetes
  • Polypharmacy – taking combination medications without realizing there are duplication of ingredients
  • Incorrect pediatric dosages given due to lack of knowledge or failing to read dosing instructions given on the packaging
  • Adverse reactions due to medication overuse or high dosages ingested

Treating colds, flu and pain with OTC medications

A runny and stuffy nose, sore throat, coughing, body aches and sinus headaches are all symptoms of the common cold and flu viruses.2 The problem with viruses is just that – they are viruses. This means that a trip to your doctor to get an antibiotic prescribed, won’t save you from the 7–14 days it takes a virus to fizzle out.2 Antibiotics are only prescribed for bacterial infections, or when a cold or flu develops into a chest or severe sinus infection.

There are, however, OTC medications for every symptom. While these products may be able to relieve your symptoms, taking multiple of them at a time puts you at a higher risk for side-effects and places extra stress on your liver to process them, as they are ultimately seen as foreign substances entering the body and ‘needing detoxification’.4,5

There is also a small chance of addiction to certain OTC products, like dextromethorphan, an opioid-type cough suppressant. The National Institute on Drug Abuse also warns against the use of nasal decongestant products containing pseudoephedrine.6 Pseudoephedrine has a stimulant effect and can be used to make the drug methamphetamine (meth; crystal meth). It is usually only handed out by pharmacists from ‘behind the counter’, but it is important to be aware of its stimulant and possible addictive nature.6,7

What are the most common OTC remedies for colds, flu and pain?

Adults can suffer from two to four colds a year, while children may experience an average of eight colds a year.8Your pharmacist is most likely going to offer you one of four types of OTC medications, either as separate tablets, or as combination preparations.3

  • Pain medication like acetaminophen (Tylenol), non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (Advil) or aspirin (Bayer)
  • Nasal decongestants like pseudoephedrine (Sudafed) or phenylephrine (DayQuil)
  • Antihistamines like diphenhydramine (Benadryl)
  • Cough suppressants like dextromethorphan (Robitussin)

The overuse of these medications can all lead to some serious side-effects. In the next section we will discuss the mechanisms of action and side-effect profiles of some of these commonly used OTC medications.

1. Adverse effects of acetaminophen

Acetaminophen is generally regarded as one of the safest pain medications to take. It can even be used for infants as young as two months with the chance of side-effects being very low. Acetaminophen is a non-opioid analgesic that is used to treat pain and fever.9 Because it is not an opioid, it will not cause any dependency. It is, however, used in combination prescription pain medications containing codeine (an opioid) for use in severe pain.9

Acetaminophen also goes by the name paracetamol, and is classed as a NSAID-type medication, though the mechanism of action is not the same and it does not have anti-inflammatory activity like other NSAIDs.9 Most OTC pain medications work by inhibiting the COX pathways that manufacture pro-inflammatory substances called prostaglandins.9 Acetaminophen appears to have an effect on the COX pathway, but is also able to reduce pain by inhibiting the central nervous system and can activate the cannabinoid system, leading to an analgesic effect.9

Acetaminophen is also prescribed as a chronic pain medication for conditions like osteoarthritis and lower back pain, giving more insight to the adverse effects of using the medication for a long-term period.10

Hepatotoxicity of acetaminophen

The standard acetaminophen tablet contains 500 mg of active ingredient. The maximum recommended intake for an adult is 4 g a day.2 Anything higher increases the chance of hepatic toxicity. The suggested dose where hepatic toxicity occurs is 8,4 g and even though the side-effects and toxicity of acetaminophen is low at low dosages, and overdose can be fatal.4 This happens because acetaminophen is broken down by the liver before it gets absorbed into the blood stream to exert its analgesic effects. Each time a small amount is converted into a byproduct that is toxic to the liver cells. This can accumulate and damage the liver cells even further, leading to toxicity.4,9 Studies have also noted that this hepatotoxic effect can be exacerbated and occur at lower dosages in people addicted to alcohol, and concomitant use of acetaminophen and alcohol ingestion is not recommended.10

The risks of using acetaminophen in pregnancy

Acetaminophen has long been used as the only safe pain medication in pregnancy. However, recent studies have found that acetaminophen and its metabolites cross the placenta and undergo a different set of changes that can have adverse effects on the fetus.10

The use of acetaminophen in pregnancy has been linked to neurodevelopment disorders in children, asthma and problems in male sexual organ development.10 A study performed in Denmark showed that children exposed to acetaminophen before birth were at a greater risk of developing hyperkinetic disorders and attention deficit hyperactivity disorder (ADHD) by the time they reached 7 years.22 Another study published in the Autism Research journal indicated that there is a strong link between maternal acetaminophen use during pregnancy and the development of autistic spectrum disorders (ASD). Mothers who used acetaminophen chronically during pregnancy (more than 20 weeks of gestation) doubled the risk of their babies developing infantile autism and hyperkinetic disorders.23

Maternal use of acetaminophen has also been linked to causing asthma and wheeze in children after birth, possibly by having an effect on lung cell development in utero. 10

Acetaminophen use linked to reduced empathy for others

A research study published in Frontiers in Psychology in 2019 has indicated that acetaminophen has the ability to reduce brain activity in areas linked to emotional awareness and motivation.24 This effect has led researchers to believe that acetaminophen can reduce positive empathy for other people. They measured this by giving participants 1000 mg or 1 g (well under the recommended dosage) of acetaminophen and then exposed them to written scenarios set to trigger empathy. The subjects taking the acetaminophen showed considerably less positive empathetic effects towards the scenarios than those taking the placebo tablets. 24 They concluded that acetaminophen could reduce affective (but not cognitive) empathy towards people. 24  

It is estimated that acetaminophen causes about 500 deaths and 50000 visits to emergency departments each year in the U.S., usually as a result of acute liver failure.9 It is very important to note which combination cold and flu medications contain acetaminophen, and not take an acetaminophen tablet for pain with them as this will increase the maximum daily dose and impact on the liver.

Other noted side-effects of acetaminophen include constipation, nausea, vomiting, possible renal toxicity, skin rashes and hypersensitivity reactions.9

2. The gastrointestinal side-effects of NSAIDs

NSAIDs are a group of medications known for their effects against pain, fever and inflammation. It is estimated that doctors write over 70 million prescriptions for NSAIDs in the U.S. each year, with the stats on OTC doses of NSAIDs reaching 30 billion.11 Popular OTC NSAIDs used for pain relief include propionic acids like ibuprofen and naproxen, and the salicylate-type NSAID aspirin.

Medications like ibuprofen and naproxen are very effective in reducing pain and inflammation. Ibuprofen can also be used in children for the effective treatment of pain and fever, from the age of 3 months, with similar efficacy and safety when compared to acetaminophen.5

Ibuprofen and naproxen work by inhibiting COX, the enzyme that converts arachidonic acid into pro-inflammatory prostaglandins, thromboxanes and prostacyclins.12 It binds non-selectively and reversibly to COX-1 and COX-2 enzymes.12 It is also because of this mechanism that most of the side-effects of ibuprofen and naproxen occur.

Aspirin has been used since ancient times as a remedy for pain, fever and inflammation. It is originally derived from willow tree bark.13 It works by selectively inhibiting COX-1 and modifies the activity of COX-2. It is also important to note that aspirin binds irreversibly to these enzymes. Because of this irreversible effect, aspirin can prevent platelet aggregation by inhibiting thromboxane, making it marketable as an anti-platelet for cardiac conditions even in low doses.13 Different than other NSAIDs, aspirin can also increase the production of anti-inflammatory lipoxins by modifying the activity of COX-2, which contributes to its potent anti-inflammatory effects.13

Common side-effects of OTC NSAIDs:12,13

  • Gastric bleeding and development of peptic ulcers
  • Possible kidney damage
  • Increased risk of cardiovascular events
  • Bleeding problems
  • Nausea and diarrhea
  • Skin irritations
  • May worsen asthma and hypertension
  • Interactions with other chronic medications

The suggested maximum daily doses for pain relief, fever and inflammation for ibuprofen is 1200 mg, naproxen 660 mg and aspirin 4000 mg.12 

Gastrointestinal adverse effects of NSAIDs

Prostaglandins released by COX-1 are responsible for building up the linings of the intestines and help to maintain organ function.11 When COX-1 is inhibited by NSAIDs, it can affect the integrity of the gastrointestinal mucosa. When this happens, a person can develop gastrointestinal symptoms like nausea and a feeling like the stomach is burning. The continuous use of high dosages OTC NSAIDs can lead to the development of gastric and peptic ulcers that may start to bleed.11,12 When bleeding occur with concomitant NSAID use, the ability of the body to naturally clot the blood will be impaired because of the inhibiting effect of NSAIDs on platelet aggregation substances like thromboxane.12,13 This effect is exacerbated with alcohol use and if the person is also on blood-thinning medication like warfarin.13

Studies have reported that there is a 15.7% chance of experiencing adverse effects when taking aspirin for cold and flu symptoms, and a 12% chance if taking ibuprofen.5 There is also a 21% chance that aspirin can induce asthma in adults.5 Ibuprofen in low doses are considered as the NSAID with the least gastrointestinal side-effects.5 Aspirin should not be used in children as there is a possibility of developing Reye’s syndrome.13

3. Decongestants may increase your blood pressure

Nasal congestion (a blocked and stuffy nose) is one of the main complaints when suffering from a cold or the flu. It can affect breathing and the overproduction of mucus can move to the chest, creating more congestion and coughing. When the nasal mucus drips down the back of the throat and into the stomach, it can cause irritation and redness in the throat and nausea.14

Treating nasal congestion falls on the use of OTC nasal decongestants. Nasal decongestants can be used either topically as sprays for the nose, or orally in syrups or tablets. The most common decongestants include pseudoephedrine (Sudafed) and oxymetazoline (Afrin). Phenylephrine is used in nasal preparations like NeoSynephrine.14

Decongestants work by exerting an effect on the alpha-adrenergic receptors. They potentiate the effects of these receptors to improve nasal drainage and ventilation through a vasoconstricting effect.15,16 When used in nasal sprays, the nasal passages will be opened immediately, however, topical use for longer than five days can cause rebound congestion and medicine-induced runny nose.15 When oral decongestants are used, they take between 30–60 minutes to work and are not as effective as topical preparations.16

Studies have indicated that topical nasal decongestants have less side-effects than tablets. The most common side-effects reported for nasal decongestants include:15

  • Increased blood pressure
  • Palpitations
  • Sleeplessness
  • Anxious feelings
  • Appetite loss
  • Headaches
  • Restlessness

Because of the mild stimulant effects of decongestants, they may cause addiction, especially when taken with other cold medications containing caffeine.6 The maximum daily dose of pseudoephedrine for adults is 2400 mg. The maximum daily dose for children is 1200 mg and should not be given to children under 6 years.17

Effect on blood pressure

Decongestants like pseudoephedrine causes vasoconstriction of blood vessels and can exert other adrenaline-like effects because it acts on the adrenergic receptors. Studies have shown that oral decongestants can cause spikes in blood pressure and increased pulse rate and palpitations.18 The studies also showed that these effects are less when taking a sustained release product, instead of an immediate release product.18 In people already suffering from high blood pressure, these medications should be avoided as they can not only cause a spike in blood pressure, but also intervene in the efficacy of the patient’s hypertensive medication.

4. Antihistamines and drowsiness

Antihistamines are some of the most common OTC medications given for sinus and nasal symptoms. Antihistamines work by inhibiting the histamine 1 (H1) receptor.14 This helps to reduce mucus secretion, bronchoconstriction, edema and smooth muscle contractions.14

Unfortunately, by blocking the H1 receptor it can cause an array of side-effects:19

  • Sedation and drowsiness
  • Confusion
  • Dry mouth
  • Headache
  • Blurred vision
  • Urinary retention
  • Psychomotor impairment
  • Constipation
  • Dry nose

First generation antihistamines like diphenhydramine and chlorpheniramine can cause severe drowsiness. This can lead to decreased concentration, falls in older people and inability to perform tasks at work, etc. There are newer antihistamines available like cetirizine (Zyrtec) and loratadine (Claritin) that do not cause sedative effects.20 However, it is the older generation histamines that are usually included in combination cold and flu preparations. To counter the effect of drowsiness, some of these combination OTC products contain caffeine, giving them a stimulant effect, especially when decongestants are included in the formulation.

It is to be noted that these synthetic antihistamines suppress a natural histamine response. Therefore, in order to completely heal one’s body, underlying issues need to be taken into consideration. Allergic reactions occur due to immune dysfunction, especially gut microbiota imbalance. To be succinct, initially, avoid the food or food product which causes allergy or unpleasant sensitivities and then work to heal the gut, and allow to the body to detox. Ultimately, slowly re-introduce the food or food product that is organic, non-gmo, and/or low-pesticide. It is not the natural real food that is an allergen, it is the environmental toxins or impurities in combination with one’s gut microbiota and poor nutritional intake and imbalances that is causing a pandemic of allergies and sensitivities.

How to use OTC cold, flu and pain medications safely

If you feel like you are getting sick, you might want to give your immune system a boost to help it fight off the virus by taking an elderberry supplement, or a vitamin C and zinc supplement.21 If your immune system is functioning optimally, the symptoms will move along quickly and you won’t have to take OTC medications.

When visiting the pharmacy to purchase OTC medications, be sure to inform the pharmacist of any chronic medications you are taking, if you are diabetic or hypertensive or have any history of gastrointestinal issues. This will help them to guide you to the correct OTC medications.3 If you are taking medications from the shelves, like products containing aspirin or acetaminophen, make sure that you read and understand the dosage instructions. Be on the lookout when taking more than one OTC medication so that there is no duplication of ingredients.3

Remember if you start to feel worse after taking any OTC medication, visit your doctor or emergency department as soon as possible.


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