You take prescribed asthma medications to alleviate your symptoms and make it easier to breath. You certainly don’t want a bad reaction to make you sick, which means your doctor has to find a different medication to treat one of your symptoms.
You can take simple steps to forestall some adverse reactions to your medications.
Adverse Reactions to Different Asthma Medications
Some asthma patients are sensitive to some medications. Some asthma medications adverse reactions can be avoided by using a substitute medication.
You may develop irritation of the mouth and throat after using an inhaled corticosteroid, according to LiveSTRONG.
If your doctor prescribes a leukotriene modifier such as Singulair, you may experience a psychological disturbance. This type of adverse reaction presents with hallucinations, increased agitation or depression. If you experience any of these psychological symptoms, call your doctor right away.
If you take prescribed oral steroids (prednisone or hydrocortisone) on a long-term basis, you are at an increased risk of developing osteoporosis, high blood pressure, muscle weakness and your immune system may be weakened. 
Other adverse reactions to an inhaled corticosteroid can include a case of chickenpox that spreads to your organs, coughing/bronchospasm, easy bruising, cataracts and glaucoma and suppressed adrenal glands, according to Clivir.
When you use a short-acting beta agonist (rescue inhaler), you may develop sinus pain, dizziness, sleeping problems, appetite changes, sore throat, hyperactivity, headache or vomiting. More serious adverse reactions include chest and ear pain, rash, swelling of the face, lips, mouth or tongue, irregular or fast heartbeat, peeling, red or swollen skin, severe headache or dizziness, breathing difficulties and a pounding feeling in your chest.  
If your doctor prescribes an albuterol/ipratropium solution and you develop hives, rash, itching skin, tightness in the chest, difficulty breathing, swelling of the mouth, lips, tongue or face, chest pain, difficulty urinating, new or worsening breathing issues, numb arm or leg, severe headache, severe stomach pain, swelling in your arms or legs, vision changes, tremors or wheezing, get immediate medical attention, according to Drugs.com. 
Clivir goes on to say that leukotriene modifiers may cause liver test abnormalities, Churg Strauss syndrome, or an inflammation of the blood vessels and skin rashes.
If your doctor injects Xolair, you may develop a viral infection, sinusitis, headache, sore throat, an upper respiratory infection, pain or swelling where you received the injection – or anaphylaxis, which is a potentially life-threatening allergic reaction. 
Why These Reactions Happen
You develop a reaction to your asthma medications after you have taken your medication and it has been in your system for some time.
Your risk of developing an adverse reaction to your asthma medications depends on your overall health, the specific cause of your asthma, your age and the condition of your immune system, according to LiveSTRONG.  LiveSTRONG goes on to say that “overuse of asthma medications, especially inhaled varieties,” increases the risk of adverse reaction.
How to Prevent or Minimize the Risk
You don’t have to leave yourself open to possible adverse reactions to your medications, regardless of whether you take them orally, use an inhaler or a nebulizer. With your inhaled medications, especially inhaled corticosteroids, rinsing your mouth out, then spitting the rinse water out, decreases your risk of mouth irritation, sores or thrush.
If you develop psychological symptoms after taking a leukotriene modifier, notify your doctor right away so he can help you.
If you receive an injection of Omalizumab (Xolair), you should stay at your doctor’s office for “at least” two hours after receiving the injection. If you develop an adverse reaction, medical staff is nearby to help you. You may receive a prescription for an Epi-Pen (epinephrine self injector) so you can administer a self-treatment should you begin developing symptoms of anaphylaxis, writes “The New York Times.” Some asthma medications adverse reactions may be severe, and if not treated right away, they can be fatal.
 https://www.livestrong.com/article/260784-asthma-medication-reactions/ – LiveSTRONG: Asthma Medications & Reactions
 https://www.clivir.com/lessons/show/asthma-medication-side-effect.html – Clivir: Asthma Medication Side Effect
 https://www.drugs.com/sfx/albuterol-side-effects.html – Drugs.com: Albuterol Side Effects
 https://www.acaai.org/allergist/allergies/Types/drug-allergy/Pages/default.aspx – American College of Allergy, Asthma & Immunology
 https://health.nytimes.com/health/guides/disease/asthma/long-term-relief-medications.html – The New York Times: Asthma Long-Term Relief Medications