Drug-induced asthma

Introduction to drug-induced asthma All drug-induced asthma attacks are collectively referred to as drug-induced asthma (drug-induced asthma), including asthma caused by the use of certain drugs in patients with asthma who have induced asthma or increased asthma attacks and no history of asthma. Asthma-induced asthma is the most common and most typical. The common feature of drug-induced asthma is that there is a clear history of medication before the onset of asthma. The onset or exacerbation of asthma has a clear time relationship with medication. After stopping the drug, after active treatment of asthma symptoms, there may be different degrees of relief or self-remission. After the class of drugs, asthma can be induced again. There are hundreds of drugs that cause asthma attacks, among which antipyretic and analgesic drugs, antibiotics, beta-blockers, iodine-containing contrast agents and protein preparations are more common. Drug-induced asthma is a special type of asthma. Because the cause is clear, once the diagnosis can be effectively prevented, the diagnosis of drug-induced asthma is particularly important in the prevention and treatment of asthma. basic knowledge The proportion of illness: 0.003% Susceptible people: no special people Mode of infection: non-infectious Complications: pneumothorax, respiratory failure, atelectasis

The cause of drug-induced asthma

So far, there are hundreds of drugs that may induce asthma attacks, which can be roughly divided into the following categories:

Antipyretic analgesics (18%):

It mainly includes aspirin and various non-steroid anti-inflammation drugs (NSAIDs), which are a class of drugs with antipyretic and analgesic effects and remarkable effects, including certain composite preparations. It mainly includes aspirin, compound aspirin (APC), painkiller (somethetin), Antongding, aminopyrine, analgin, paracetamol, cold-flux, compound theophylline, compound chlorpheniramine, anti-inductive No. 5, Bao Taisong, Ke Senmin, Quick-acting cold capsule, indomethacin, ibuprofen (Fenbid), naprofen, ketoprofen, Flufuriprofen, Piroxicam, methotrexate, chlorinated acid, diclofenac , sulindac, allyl phenylacetic acid, naproxen, phenoxyprofen, ketoprofen.

Antibacterial (15%):

Penicillin, ampicillin, cephalexin, cefotaxime, erythromycin, polymyxin B, streptomycin, vancomycin, bleomycin, neomycin, tetracycline, chloramphenicol, griseofulvin, helix Neomycin, gentamicin, lincomycin, capreomycin, amphotericin, pingyangmycin, oleandomycin, pipemidic acid, sulfonamides, furans. Patients may have a history of allergies to many drugs. Asthma can occur during the course of medication, and some patients can also induce asthma when doing allergy tests. Asthma is often accompanied by other allergic diseases such as rash, laryngeal edema, shock and so on.

Beta-blockers (10%):

The heart is calm, the heart is flat, the heart is calm, the heart is quiet, timolol, atenolol and metoprolol. It is worth noting that asthma is also reported in people who have not had a cardiopulmonary disorder with a higher dose of propranolol. In addition, 0.5% timolol eye drops can also induce severe bronchospasm in susceptible patients.

Angiotensin converting enzyme inhibitor (9%):

Captopril, enalapril, benazepril, perindopril, ramipril, lisinopril, and spirapril, these drugs can inhibit the degradation of bradykinin, thereby inducing airway hyperresponsiveness.

Iodine-containing contrast agent

Such as iodized oil, ethyl iodide oil, iodophenyl ester, iopanoic acid, iohexol, isosine, diatrizoate, etc., the incidence is less than 2%, injection of 0.5-1.0ml containing iodine contrast agent can cause Severe asthma attacks, even death, any type of iodine-containing contrast agent can induce asthma, but the contrast agent containing methylglucamine causes the highest incidence of asthma.

Anesthetic and muscle relaxant

Procaine, lidocaine, cocaine, thiopental sodium, brominated pen Cronin, myostatin, choline succinate, the mechanisms by which these drugs induce asthma remain unclear.

Protein and enzyme preparation

Insulin, ACTH, cytochrome C, posterior pituitary powder and extract, streptokinase, trypsin, alpha-chymotrypsin, aprotinin, various vaccines and anti-venom, oral pollen preparation, nyprofen phenylpropionate, Gamma globulin, adenosine triphosphate.

Choline preparation

Acetylcholine, methacholine, pilocarpine, succinylcholine, Tengxilong, neostigmine, galantamine, pilocarpine.

Antihypertensive drugs

Reserpine, methyldopa, sputum.

Antiarrhythmic drug

Quinidine, procainamide, digitalis, amiodarone.

Sympathomimetic drug

Isoproterenol (wheeze), adrenaline, and ephedrine are associated with a large dose.

Anthelmintic

Repelling the spirit, praziquantel, pentamidine, sea group.

Antituberculosis drugs

Para-aminosalicylic acid, pyrazinamide, ethambutol, ethionamide, rifampicin.

other

Certain vaccines, tetanus antitoxin, pyrazolone derivatives, viline, aminophylline, chlorpheniramine, azathioprine, caffeine, morphine, sodium dehydrocholate, thiouracil, codeine, Warfarin, barbital, vitamin B6, vitamin K, camphorquinone, dextran, acetazolamide, cimetidine, mannitol, progesterone, anisodamine, atropine, histamine, anti-glare, amitriptyline , chlorpromazine, calcium gluconate, sodium cromoglycate, hydrocortisone (alcohol preparation), dexamethasone, beclomethasone propionate aerosol, etc. have the possibility of inducing asthma attacks.

Drug-induced asthma prevention

Since most patients with drug-induced asthma do not understand that they can induce asthma, prevention is often impossible, so clinicians should pay attention to the following points in the prevention of drug-induced asthma:

1. All the asthmatic drugs that have been identified should be stopped immediately. The names of the asthmatic drugs (including other trade names) should be indicated to the patients and their families at the same time as the medical records on the front page to avoid repeated application of these drugs.

2. For every asthma patient who is treated, you should carefully ask if there is a history of drug allergy or drug-induced asthma.

3, for the application of new drugs in asthma patients should carefully observe whether there are adverse reactions.

4, asthma patients in the course of treatment during the symptoms are not relieved but worse, in addition to a variety of factors should be thought of the disease itself, but also always consider the possibility of drug-induced asthma, such as suspected drug-induced asthma should be discontinued observation.

5. Allergy tests must be performed before using iodine contrast agents. For asthma patients with allergic constitution or previous history of iodine allergy, try not to use iodine-containing contrast agent. If it is really necessary, give antihistamine and glucocorticoid (such as prednisone 5mg) before administration (18-24 hours). , every 6 hours, a total of three times).

Drug-induced asthma complications Complications, pneumothorax, respiratory failure, atelectasis

1, bronchial, lung infection: It is currently recognized that respiratory viral infection can stimulate and aggravate the onset of bronchial asthma, and easily secondary to bronchial and pulmonary infection. Therefore, patients should pay attention to improve immune function, prevent colds and keep breathing, so as to reduce infection.

2, pneumothorax and mediastinal emphysema: the incidence is low, about 5%, due to airway obstruction caused by excessive alveolar expansion or pulmonary bullae formation, if the alveolar internal pressure is too high, such as severe cough, forceful sputum The alveolar rupture, gas into the chest and abdomen subcutaneous tissue mediastinum caused by pneumothorax, subcutaneous emphysema, life-threatening.

3, respiratory failure Severe asthma: due to inadequate ventilation, infection, improper treatment, improper medication, and complicated atelectasis and pulmonary edema, may induce respiratory failure, making drug-induced asthma treatment more difficult. Prevention of respiratory failure should occur in response to early detection of predisposing factors.

4, atelectasis: drug-induced asthma attacks increased secretions, sputum viscous, and bronchospasm, causing mucus plugs obstruct the airway atelectasis.

Drug-induced asthma symptoms common symptoms wheezing chest tightness breathing difficulties cough

Often manifested as episodes of wheezing, cough, chest tightness and difficulty breathing.

Drug-induced asthma test

Common laboratory tests are:

(1) sputum smear: visible small airway tube type and eosinophilic fragmentation products, are characterized by asthma. Sputum smear to find broken products of eosinophils and Gram stain to find bacteria to identify the presence or absence of infection.

(2) Skin Sensitive Test: Use a suspicious allergen carefully as a skin scratch or intradermal test to help identify allergens.

(3) Determination of IgE and IgA in blood and respiratory secretions: IgE increases in allergic reactions, and IgA increases or decreases in infection with viruses and bacteria.

(4) Airway sensitization measurement: Airway stimulation was performed with some known allergic substances to observe the reactivity of the airway.

Diagnosis and identification of drug-induced asthma

Diagnostic criteria

The diagnosis of drug-induced asthma includes non-specific diagnosis and specific diagnosis. The non-specific diagnosis is to determine whether the patient's asthma symptoms are caused by drugs. The detailed medical history is important for the diagnosis of drug-induced asthma. The medical history inquiry includes the history of medication. History of allergic disease, family history of allergies, and the relationship between the onset of asthma and drugs. Specific diagnosis is mainly used for asthma caused by drug allergy. Drug-induced asthma often has the following characteristics:

l. Have a clear history of the application of suspicious drugs, and should ask whether there is a history of atopic traits. Drug-associated asthma patients with atopic traits are often associated with allergies.

2. A typical asthma attack occurs within a few minutes to a few days after the application of a certain drug or the original asthma is aggravated. Usually, the incubation period of certain specific drugs induces asthma is relatively fixed.

3. Most asthma can be relieved quickly after stopping the drug and giving appropriate treatment.

4. When the same drug or the same drug is used again, asthma can recur.

5. Asthma caused by allergic reactions, often accompanied by other clinical manifestations of allergic reactions, such as rash, urticaria, laryngeal edema, anaphylactic shock.

According to the above characteristics, it is not difficult to make a diagnosis of drug-induced asthma in clinical practice. The key point is that there should be sufficient awareness and vigilance in clinical work. If it is still uncertain, consider a specific diagnosis such as a drug allergy skin test, an in vitro immunoassay, or a drug challenge test.

Differential diagnosis

It is differentiated from bronchial asthma and cardiogenic asthma.

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