Side Effects: Definition, Types, FDA Role and Favorable Results

It refers to any unwanted effect caused by a drug.

All medicines have side effects, but the side effects are milder in many people, or patients can deal with them.

These side effects give rise to unwanted symptoms caused by medical treatment.

They are also called ” adverse effects ” or “adverse reactions.”

All medications can cause side effects, especially if you do not use them as recommended.

This includes prescription drugs, over-the-counter medications, herbal remedies, and natural supplements.

Side effects can range from mild, such as drowsiness or discomfort (nausea), to severe, as life-threatening conditions, although these are rare.


The risk of side effects varies from person to person.

You should consult the brochure that is provided with the medication.

But generally, the benefits of the medication are more important than the minor side effects.

Some of the side effects may disappear after taking the medication for a while, but when side effects continue to occur, you should see the doctor know what should be done in these cases.

The specialist can reduce the dose or change your medication.

Do not stop taking the medication suddenly unless the doctor says so.

Emergency services should be called immediately if the patient has the following symptoms when taking medication:

  • Trouble breathing.
  • Swelling of the face, lips, tongue or throat.
  • Weakness or loss of consciousness or feeling that you may faint.

Since these are signs of a severe allergic reaction to the medication.

All drugs have side effects, from homemade aspirin to the most sophisticated prescription medicine.

Many are minor, some are just an inconvenience, others are serious, and some are simply strangers.

The gastrointestinal system is perhaps the most common side effect of drugs that work inside your body.

Almost any drug can cause nausea or upset stomach; for medications that are for topical use, skin irritation is a common complaint.

For more information about the side effects of a medication, see the label of the over-the-counter products or on the leaflets or printed materials that have the prescription drugs.

Because inserts often include a long list of possibilities, you may also need to talk to your doctor about these effects and what to expect.

I need to see a doctor

If you believe that if the patient is having a severe allergic reaction to a medication, immediate medical help should be sought.

Contact your general practitioner or pharmacist immediately if:

  • If a side effect appears as severe in the medication information leaflet.
  • If a side effect occurs, that is serious even when not in the medication information leaflet.

You do not need to see your doctor when there are mild side effects, such as nausea, especially if the patient can manage them independently.

Report side effects

The side effects of a medication must be reported through the yellow card scheme.

A free application is available for iOS and Android devices, which allows you to report side effects through your phone or tablet.

In the option of How do I report the side effects of a medication?

Side effects that a medication can have

The information leaflet of the medicine supplied will show its known side effects.

If you do not have the information leaflet for the medication, you can find a copy in the online electronic medication compendium.

The medication information leaflet will show if each side effect is:

  • Very common: more than 1 in 10 people are affected.
  • Frequent: between 1 in 10 and 1 in 100 people are affected.
  • Uncommon: between 1 in 100 and 1 in 1,000 people are affected.
  • Rare: between 1 in 1,000 and 1 in 10,000 people are affected.
  • Very rare: less than 1 in 10,000 people are affected.

Types of side effects

An allergic reaction can occur with any drug.

This can range from pruritus and rash to a potentially fatal anaphylactic reaction.

Some drugs can not avoid triggering side effects due to their chemical structure.

The standard medication for the allergy diphenhydramine (also known by the brand Benadryl) is one of them.

Although it relieves allergy symptoms, it also blocks the chemical acetylcholine, which causes drowsiness and a host of other side effects, including dry mouth.

Some drugs have barely noticeable side effects in the correct dose.

Generally, warfarin (Coumadin, Jantoven), used to prevent blood clots, usually works well and is not bothersome, but it can also cause severe internal bleeding.

Side effects can occur only when a medication is mixed with other medicines. This could be called a drug interaction.

For example, drinking alcohol while taking narcotic painkillers can cause an accidental overdose.

Another example is grapefruit juice, which can affect the blood levels of several medications, including some medicines for blood pressure and cholesterol.

The role of the FDA

Before a medicine goes on the market, the Food and Drug Administration must approve it.

New drug applications filed by pharmaceutical companies have evidence that the drug has the effect it is supposed to have and is safe.

This test comes from testing the drug, first in animals and then in humans.

Once the basic safety and efficacy issues are resolved, the Food and Drug Administration will approve the medication if its benefits outweigh its risks.

However, sometimes the tests do not reveal everything about the side effects of a medication, and they do not appear until after the medicine enters the market and more people start using it.

That’s where the Food and Drug Administration program comes in.

The post-marketing surveillance program of the Food and Drug Administration seeks voluntary contributions, mainly from health professionals, about the unwanted effects they see in the real world.

Sometimes these reports are numerous or severe enough for the Food and Drug Administration to recommend its use and exercise regulatory action, such as adding warnings to the medication label; this happened with the medication for psoriasis Raptiva.

The Food and Drug Administration required that the medication carries in its container the strongest warning from the agency, known as a black box warning; after it received reports of brain infections and meningitis in patients taking the medication, the drug was then withdrawn from the market.

The Food and Drug Administration also wants information from consumers regarding side effects.

All prescription medications and many over-the-counter products must be labeled with a toll-free number that the agency has to tell you about the side effects of the medicines, called “adverse events.”

Sometimes, post-marketing information that enters the Food and Drug Administration is so disturbing that medication is suspended.

Baycol, which reduces cholesterol, was strongly related to a breakdown of muscle tissue that could be deadly.

The drug was approved in 1997, and the manufacturer stopped selling it four years later.

The anti-inflammatory drug Durant spent only one year on the market and was approved only as a short-term product. The Food and Drug Administration program discovered serious liver problems when people took the medication longer.

Pharmaceutical companies must also report adverse events to the Food and Drug Administration program. Otherwise, it may result in prosecution.

In 1985, employees of two pharmaceutical companies were fined or sentenced to community service for failing to report adverse events involving the blood pressure medicine Selacryn and the Oraflex arthritis drug.

Both products were subsequently taken off the market.

Favorable results

Not all side effects are harmful. Some are frankly welcome.

In the case of finasteride, introduced in 1992 to treat the noncancerous enlargement of the prostate gland, it was discovered that it made the hair grow.

Now it is marketed for that purpose under the name of Propecia.

Today, millions of men use a low dose of finasteride to treat male pattern baldness.

Similarly, minoxidil was initially marketed as a pill for high blood pressure, and it was discovered that there was hair growth in people who used it.

Today, as a lotion or foam, it is a popular medication for treating baldness.