What drugs should be avoided with sulfa allergy?

Posted on  November 9, 2020, Edited by Jason, Category  

Quick Navigation

  1. What is a sulfa allergy?
  2. Sulfa Allergy Symptoms
  3. Drugs should be avoided
  4. How to treat sulfa allergy
  5. Conclusion

What is a sulfa allergy?

Sulfa allergy is a very painful thing for every patient. Sulfa allergy has many symptoms, such as peeling, blisters, rash, and itchy skin. These symptoms have brought great pain and inconvenience to patients. Nowadays, there are many treatment methods for sulfa allergies. These methods can not only alleviate the suffering of patients, but also help patients completely cure sulfa allergies.

When a patient is suspecting that he is allergic to sulfa, it is particularly important to understand some symptoms of sulfa allergy. Patients can use these symptoms to determine whether they are sulfa allergic, so that they can take the medication as soon as possible or seek help from the doctor to avoid delay in treatment.

If you eat dairy products, Ballya can also perform a sulfonamides test to tell you if there are sulfonamides residues in them.


Sulfa Allergy Symptoms

There are many adverse reactions to sulfa compounds, among which allergic reactions are the most common, with an incidence of about 1% to 3%. The clinical manifestations are drug eruptions, even serious adverse reactions such as exudative erythema multiforme, exfoliative dermatitis and epidermolysis bullosa atrophy. However, there is no need to "go pale at the name of sulfa allergy."

In fact, the possibility of cross-allergic reactions in patients who are allergic to sulfa antibiotics in the academic community has been controversial. Some scholars have confirmed for patients with a history of allergy to sulfa antibiotics, the allergic reaction after using sulfa non-antibacterial drugs is not a cross-allergic reaction, but is related to the increased susceptibility of the patient's own allergic reaction.

There are various symptoms of sulfa allergy, but most of them are rashes, itchy skin, erythema papules, blisters, peeling and other symptoms. More serious is that it will aggravate asthma and even cause anaphylactic shock, endangering the lives of patients.

Drug allergic dermatitis is abbreviated as drug eruption, which is the inflammation of the skin and mucous membranes caused by drugs that enter the human body through oral administration and injection. Drug allergic dermatitis is very harmful to the human body. Almost all medicines in orthopedics can cause dermatitis at a rapid rate, but the most common are iodine drugs, antipyretic analgesics, sleeping pills, penicillins, streptomycin, etc.

Fixed erythema drug eruption is a common type. The shape is special and easy to identify. The rash is characterized by limited round or oval erythema, bright red or purple-red erythema, edema, and blisters can form in the center of severe inflammation. The area of damage is clear, and there are pigment spots after healing. After each application of sensitizing drugs, the damage will be aggravated at the same site, and some new damages are added at the same time.

The number of rashes can be single or multiple, and some are distributed throughout the body. The size of the rash is generally 0.2 cm to several centimeters, the rash can occur in any part of the body, especially the skin and mucous membrane junctions such as the lips and mouth, glans, anus, skin between the toes, the back of the hand, and the dry back of the foot.

Common Symptoms

  1. Skin and lung reactions: Skin reactions are one of the most common reactions. Its adverse effects range from skin rashes, life-threatening Stevens Johnson syndrome (SJS), to toxic epidermal necrosis. In some cases, it is also possible to increase sensitivity to sunlight. Sulfa allergy can also affect the lungs and cause pneumonia-like reactions and increase asthma problems.
  2. Blood reaction: Sulfonamide reaction can affect blood cells, leading to a decrease in white blood cells, red blood cells and platelets.
  3. Joints and muscles: It may cause severe joint irritation and muscle pain. The reaction usually starts within a week of starting the medication.
  4. Breathing problems: As it affects the lungs, it will aggravate asthma.

Drugs should be avoided

Sulfonamide drugs are actually a broad concept. All drugs containing a sulfonamide group (-SO2NH2) structure are considered sulfonamide drugs, not limited to sulfonamide antibiotics. Commonly seen sulfa drugs, such as sulfasalazine for ulcerative colitis, silver sulfadiazine ointment for burns, and sodium sulfa-cetamide eye drops for conjunctivitis, will be marked "It is prohibited for people who are allergic to sulfa drugs.

In fact, there is also a class of drugs. Although the name "sulfa" is not written with sulfa, the chemical structure is similar to that of sulfa antibacterials, which can cause cross-allergic reactions. The following drugs should be used with caution or banned in patients with sulfa allergies:

  1. Sulfonylurea hypoglycemic agents: such as tolbutamide, chlorpropamide, glibenclamide (glyburide), glipizide (mepyrida), gliquidone (sugar level), Gliclazide (Damekang), etc. The instructions of these drugs clearly state that "for those who are allergic to sulfonamides are prohibited."
  2. Antipyretic: analgesic and anti-inflammatory drugs Cyclooxygenase-2 inhibitors, such as celecoxib, cannot be used for "known sulfa allergies".
  3. Antihypertensive drugs: Indapamide, such as Shoubishan, Naqili, etc. And the instruction manual also clearly states "prohibited for sulfa allergy".
  4. Drugs for the treatment of glaucoma: Acetazolamide and brinzolamide (pelimin) are carbonic anhydrase inhibitors, and those who cannot tolerate sulfa drugs or other sulfa derivatives cannot tolerate this product.
  5. Diuretics: People who are allergic to sulfa drugs may also be allergic to the diuretics furosemide and hydrochlorothiazide should avoid sulfa drugs as much as possible.
  6. Sulfasalazine: The drug sulfasalazine used to treat ulcerative colitis and Crohn's disease is actually a sulfa drug, and it is forbidden for people who are allergic to sulfa drugs.
  7. Medications for gout: Probenecid is a commonly used drug for the treatment of gout, and those who are allergic to sulfa drugs should also avoid it.
  8. Sulfone drugs: Sulfone drugs such as dapsone are also forbidden for those who are allergic to sulfa drugs.
  9. Compound preparations: Patients who are allergic to sulfa drugs should not only prohibit the above drugs, but also pay special attention to some compound preparations containing the above drugs (such as pills containing glibenclamide).
  10. Saccharin: A synthetic sweetener is a derivative of toluene sulfonamide, which may also have cross-allergic reactions with sulfonamide drugs.

How to treat sulfa allergy

After allergies occur, they should be treated in time. For acute symptoms, consult a doctor for emergency treatment.

There are two necessary factors for the occurrence of drug allergies: allergic constitution and contact with drugs, both are indispensable. The former is genetically determined, and there is currently no way to change it. People with genetic allergies account for about 1/3 of the population or more, and these people are prone to allergic diseases, such as allergic rhinitis, bronchial asthma, urticaria, eczema, etc.; The latter is exposure to allergenic drugs. Not all drugs can cause allergic reactions. The drug that can cause allergic reaction is called a sensitizer. Therefore, drug allergy only occurs in people with allergic constitution and must be triggered by medication.

In order to protect our health, each of us should know some methods to treat sulfa allergy. Here are some methods.

  1. Pay attention to your diet. Avoid spicy food, tobacco, alcohol and seafood. The above-mentioned foods will not only relieve allergic symptoms, but may even aggravate allergic symptoms. During allergies, you should prefer a light diet with less salt and less oil, and drink plenty of water to expel toxins from the body and clean up the body as soon as possible.
  2. Pay attention to your diet. Avoid spicy food, tobacco, alcohol and seafood. The above-mentioned foods will not only relieve allergic symptoms, but may even aggravate allergic symptoms. During allergies, you should prefer a light diet with less salt and less oil, and drink plenty of water to expel toxins from the body and clean up the body as soon as possible.
  3. Keep a happy mood. During allergies, the patient's mood will not be very good because of physical discomfort. But a positive mood can help your body heal itself as soon as possible, so try to maintain a happy mood during allergies.
  4. Exercise moderately. Appropriate exercise can help you detoxify yourself and relieve allergic symptoms as soon as possible, but excessive exercise will aggravate the condition and the symptoms of allergies, so you must pay attention to the amount of exercise.

I hope the several methods introduced above could be helpful to everyone, but everyone's physique is different, the above methods may not be effective for everyone. After discovering the symptoms of sulfa allergy, if the symptoms of sulfa allergy are not relieved after using some methods, please you should rush to the hospital as soon as possible and carry out effective treatment according to the doctor's diagnosis. Do not delay the best time for treatment.

Patients with a history of allergies in the past often indicate that patients are more susceptible. At the same time, in view of the legal effect of the drug instructions, in line with the protection of patients and medical staff, patients who have been allergic to sulfa drugs, should avoid the use of drugs that indicate "prohibited for patients with sulfa drug allergy" in the instructions and use "Possibly cross-reactive" drugs with caution.

If the patient has medication contraindications, but there is no better alternative drug treatment due to the condition, then it should be judged based on the patient's past response to sulfa antibiotics: if the patient has a previous severe or life-threatening allergic reaction, such as immediate hypersensitivity, toxic epidermal necrosis and hepatotoxicity, etc., the sulfa drugs should not be used; if the patient’s previous reaction is mild to moderate, under the premise of no other better alternative drugs, the dose can be reduced under close monitoring at the start.

Once allergic symptoms occur, immediately stop the suspected allergenic drugs, drink a lot of water or infuse to promote the excretion of drugs in the body. Mild patients can be treated with antihistamines, vitamin C, and calcium for anti-allergic reactions. In severe situation, glucocorticoids can be used. In case of severe drug eruptions, various treatments can be used as soon as possible.  


People who have sulfa allergy should not consume sulfa drugs under a general principle. There is currently no thorough method to eradicate such diseases. If you have allergic symptoms, you should go to the hospital in time.


Recent Posts

Proudly designed by BALLYA
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram