Drug Allergies

There are several types of "adverse reactions" to medications, including drug allergies. A drug allergy is a group of symptoms caused by an allergic reaction to a medication.

Most medications produce several different effects in your body. They produce the desired effect of relieving symptoms or helping to cure an illness or medical condition, but they can also produce other effects that you don't want. Although most people use the term "side effect," the term adverse drug reaction is a more appropriate general term for effects that are undesired, unpleasant or potentially harmful.

In general, adverse reactions to drugs are fairly common. Almost any medication can cause an adverse reaction. Reactions range from irritating or mild side effects, such as nausea and mild rash, to allergic responses including life-threatening anaphylaxis (see "Types of drug allergy").

What is the difference between a side effect and a drug allergy?

Sometimes it's tough to know the difference! But having a side effect to a medication does not mean you're allergic to it. Side effects are more common, do not involve the body's immune system, are more likely to occur at higher doses, and can often be prevented. Different people may have different side effects from the same medication. Researchers are finding out that genetics may play a role in how people respond to medication.

Side effects are usually an extension of the way the medication works in your body. For example, a pill taken to lower blood pressure may lower it too much. This could make someone feel faint when they stand up. In many cases, the higher the dose of the medication, the more likely a side effect will occur.

Drug allergies are less common, involve the body's immune system, can occur with any dose of medication, and can be life threatening.

All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/Drug-Allergies

An allergic reaction occurs when the body's immune system produces antibodies and activates disease-fighting cells in response to an offending substance in the environment – in this case, a specific drug.

The antibodies release chemicals that injure the surrounding cells and cause the physical symptoms of an allergic reaction. Certain specialized cells in the skin and mucous membranes release chemicals known as histamines.

In the first step of drug allergy development, the body becomes sensitized (i.e., the immune system is triggered) by the first exposure to the medication. A subsequent exposure causes an immune response, including the production of antibodies and release of histamine. Therefore, drug allergy reactions occur after a person has been previously exposed to the drug one or more times without any allergic reaction.

Drug allergies may be due to the direct effects of a medication, as occurs with penicillin, vaccines, blood transfusions, insulin and intravenous (IV) fluids. These medications involve the body's immune system directly.

Other drug allergies may be caused indirectly by medications that do not involve the immune system but trigger histamine release in the body. Medications such as ASA and anti-inflammatory drugs, morphine and related medications (known as opiates), local anesthetics, and some fluids given intravenously during X-rays can indirectly cause drug allergies.

In general, the number and severity of adverse reactions increase as the dose increases. However, this relationship doesn't apply to people who are allergic to a medication. For these people, even small amounts of the medication can trigger an allergic reaction, which can range from minor and simply annoying to severe and life threatening.

In theory, all medications can cause allergic drug reactions. Some common medications that have been associated with allergic reactions include:

• antibiotics such as penicillin, cephalosporins, and sulphonamides
• blood pressure medications such as ACE inhibitors
• opiates such as codeine and morphine
• non-steroidal anti-inflammatory drugs (ASA-like drugs) such as ibuprofen and indomethacin

All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/Drug-Allergies

Several different types of drug allergic reactions can occur: reactions can range from a rash to joint pain or kidney problems. The body's response can affect many organ systems, but the skin is the system most frequently involved.

Drug allergies can vary greatly in severity. They may be dangerous, as the body's response can happen very quickly with a strong reaction (within 1 to 15 minutes), which can be life threatening, as in anaphylaxis (see below).

In contrast to other types of adverse drug reactions, the number and severity of allergic reactions do not usually correlate with the amount of medication taken. For people who are allergic to a drug, even a small amount of the medication can trigger an allergic reaction. Examples of reactions are:

• skin rashes and itching
• fever
• constriction of the airways and wheezing
• swelling of the upper throat, which impairs breathing
• a decrease in blood pressure, sometimes to dangerously low levels

Serum sickness is a delayed type of drug allergy that occurs a week or more after exposure to a medication or vaccine. The immune system misidentifies a medication or a protein in the vaccine as a potentially harmful substance, and it develops an immune response to fight it, causing inflammation and various other symptoms.

Symptoms of serum sickness do not develop until 7 to 21 days after initial exposure to the medication or vaccine. However, people may develop symptoms in 1 to 3 days if they have previously been exposed to the medication or vaccine.

Anaphylaxis is a sudden, potentially life-threatening allergic reaction that involves the whole body. Symptoms can develop within seconds or minutes.

Symptoms of anaphylaxis may include the following:

• difficulty breathing
• wheezing
• rapid or weak pulse
• irregular heartbeat or palpitations
• blueness of the skin, including the lips or nail beds
• swelling of the upper throat
• fainting, light-headedness, dizziness
• skin redness, hives, and itching
• nausea, vomiting, diarrhea, abdominal pain or cramps
• confusion or anxiety
• slurred speech

Anaphylaxis is an emergency condition requiring immediate medical attention. Call your local emergency number (such as 9-1-1) as soon as you experience any of these symptoms. Early treatment is crucial!

People with known severe allergic reactions may carry an injection containing epinephrine (e.g., EpiPen, Twinject) or other allergy kit in addition to wearing a MedicAlert bracelet.

All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/Drug-Allergies

The signs of an allergic reaction can range from mild to life threatening. Some allergic reactions can occur without any previous symptoms of an allergy. Make sure you talk to your doctor or pharmacist right away if you experience anything unexpected after starting a new medication.

Most allergic reactions occur within one hour of taking the medication, and involve the following common signs and symptoms:

• hives (itchy, slightly red and swollen patches on the skin)
• skin rash
• itching of the lips, tongue and/or face
• sensitivity of the skin to sunlight (an itchy and scaly rash when skin is exposed to sun)

Within 1-2 weeks of taking a medication, these additional signs and symptoms may be present:

• fever
• muscle and joint aches
• swollen throat glands (lymph nodes)

Low blood pressure, wheezing, and other signs may indicate a potentially life-threatening reaction known as anaphylaxis (see "Types of drug allergy").

All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/Drug-Allergies

Most drug allergies respond well to treatment. Proper treatment combined with stopping the "culprit" medication can help most people to start to recover from a mild-to-moderate medication allergy reaction in 48 to 72 hours.

The first step in treating a drug allergy is stopping and avoiding the allergy-causing medication and other related medications. Mild allergy symptoms (rash, itching and mild hives) may be relieved with antihistamines such as diphenhydramine or chlorpheniramine, and topical corticosteroids may also be recommended ("topical" means "applied to a specific area of the skin"). If asthma-like symptoms such as cough and/or wheezing are present, your doctor may prescribe an inhaler that opens up the airways to make breathing easier.

After consulting your doctor about medication treatment, you can help speed your recovery from mild reactions (such as hives or skin reactions) with non-medication techniques such as:

• taking cool showers or applying cold compresses
• wearing loose clothing that doesn't irritate your skin
• applying calamine lotion to your skin
• getting plenty of rest and good nutrition until your body recovers from the reaction

Severe allergy symptoms (such as anaphylaxis – see "Types of drug allergy") may require immediate medical attention in a hospital and medications to quickly reverse the chain of events involved in the reaction. This treatment may involve:

• antihistamines such as diphenhydramine or cetirizine
• corticosteroids given orally (e.g., prednisone) or by intravenous injection (e.g., methylprednisolone)
• epinephrine given by intravenous or intramuscular injection or by inhalation
• continued therapy and observation in a hospital, for severe reactions
• salbutamol given by inhalation

Seeking medical attention immediately upon experiencing symptoms improves the chances of successful treatment for a severe drug allergy.

Call your doctor or pharmacist if you are taking a medication and develop symptoms that might suggest a drug allergy. If you have difficulty breathing or develop other symptoms of anaphylaxis (see "Types of drug allergy"), call 9-1-1 and speak with emergency personnel.

If you have been diagnosed with a drug allergy, follow up with your doctor after the diagnosis. Your doctor and pharmacist might recommend a different dose for your medication, or another type of medication entirely, in addition to a MedicAlert bracelet.

All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/Drug-Allergies

The fewer medications you are required to take, the lower your chances of having a drug allergy. Only use medications if absolutely required or if specifically prescribed to you.

For people with a known drug allergy, avoiding the allergy-causing medication is the best way to prevent allergic reactions from occurring.

Tell all health care providers, including physicians, pharmacists, dentists, nurses and hospital personnel, if you have any known drug allergies. Also tell your health care providers about any medications (prescription or over-the-counter) and herbal products you are taking.

What else can you do to prevent drug allergies?

If you know that you're allergic to one member of a drug family, avoid all other members of that family unless your doctor tells you otherwise.

Some people who are allergic to penicillin, for example, can't take other medications in that family of medications.

To help prevent drug allergies:

• Never use someone else's medication.
• If you have known drug allergies, wear a MedicAlert bracelet so that medical personnel are aware of your condition, in case you need emergency treatment.
• Inform all health care professionals (e.g., doctors, dentists, pharmacists) of your known drug allergies.
• Talk to your doctor about whether desensitization treatment (in which very small and gradually increasing amounts of the drug are injected to reduce the allergic reaction) is right for you.

If you suspect a drug allergy or other adverse drug reaction, have the following information handy to report to your health care provider and/or emergency personnel:

• personal information (your height and weight; health care number; name of physician; insurance information)
• date and time of reaction
• nature of reaction or problem
• relevant personal medical history (e.g., known allergies, pregnancy, smoking and alcohol use, other medical conditions)
• name of the medication you suspect caused the reaction (common or generic name, labeled strength, manufacturer name and expiry date, if known)
• dose, frequency and route used (i.e., did you take the medication by mouth, applied to your skin, as an injection or inhalation?)
• therapy dates (start to finish)
• other medications you are taking or have taken recently, including prescription and over-the-counter medications, vitamins, supplements and herbal products

All material copyright MediResource Inc. 1996 – 2024. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/healthfeature/gethealthfeature/Drug-Allergies