Asthma Treatment Pharmacology Quiz

Drugs and Asthma

• Asthma is a chronic respiratory disease characterized by recurring inflammation and narrowing of the airways.
• The respiratory system includes the nasal cavities, throat, trachea, bronchi, bronchioles and alveoli.
• Asthma can result in impaired breathing. The airways become inflamed, thickened, and constricted.

Asthma Stages

• Airways are relaxed in normal conditions, while they constrict with an Asthma attack.
• During an asthma attack, air becomes trapped in the alveoli, and the muscles tighten.

Drug Treatment of Asthma

• Intermittent Reliever Therapy: Short-acting beta-2 agonists (SABA), given via inhalation, act quickly to relax the airways.
• Regular Preventer Therapy: A regular, low-dose inhaled corticosteroid prevents the ongoing inflammation that contributes to asthma episodes.
• Initial Add-In Therapy: Leukotriene receptor antagonists and long-acting beta-2 agonists (LABA) are added for extra control.
• Additional Controller Therapy: Other controller medicines such as theophylline and long-acting muscarinic antagonists (LAMA) may be added.
• Continuous Corticosteroid Therapy: Oral corticosteroids like prednisolone are prescribed for sustained control of severe or persistent asthma.

Inhalers, Spacers and Nebulisers

• Using a spacer with a metered dose inhaler (MDI) to help deliver medication directly into the lungs rather than into the mouth. Decrease of oropharyngeal deposition is the benefit.

Short-acting β2-adrenoceptor agonists (SABA)

• These medications, like salbutamol and terbutaline, rapidly relax the smooth muscles in the airways.
• These drugs are rapidly absorbed and have an immediate effect.
• They come with risks, such as tachycardia, and hypokalaemia. Other side effects can include tremors.

SABA - Mechanism of Action

• SABAs bind to beta-2 receptors on smooth muscle cells.
• This binding triggers a cascade of events leading to cyclic AMP (cAMP) production.
• Increased cAMP levels cause relaxation of the smooth muscles in the airways, improving airflow.

SABA - Metered Dose Aerosol

• Metered-dose inhalers (MDIs) are the most common way to deliver SABAs.
• They use a propellant to aerosolize the medication.
• Some propellants are harmful or environmentally problematic.

Inhaler Vs Spacer

• A spacer device is added to an inhaler for more efficient delivery of medication to the lungs.
• With a spacer, one can breathe in slowly and deeply and helps avoid medication being deposited in the mouth and throat

Breath-activated inhalers

• Dry powder inhalers release medication when inhaled.
• Types of dry powder inhalers include autohalers, accuhalers, turbohalers and diskhalers.

SABA - Adverse Effects

• Tolerance to SABAs, or resistance, may develop over time.
• People can experience tachycardia, hypokalaemia, and tremor.
• These are more pronounced with oral dosing

Regular Preventer (Maintenance) Therapy

• A regular low dose (inhaled) corticosteroid is vital in maintaining asthma control.
• If the symptoms reoccur, or become worse at night, a doctor might recommend including a low dose corticosteroid.

Inhaled Corticosteroids

• Inhaled corticosteroids can inhibit mediator release from mast cells and monocytes to reduce inflammation.
• Some examples of inhaled corticosteroids include beclomethasone, fluticasone and budesonide.

Inhaled Steroids

• Long-term use of inhaled corticosteroids can have problems, such as a slow onset of asthma relief, and possible side effects including oral candidiasis.
• There is the possibility of adrenal suppression from inhaled corticosterioids. GI tract is a location for poor absorption and extensive first pass metabolism.

Step 3 Initial Add-In Therapy

• Leukotriene receptor antagonists (oral) and inhaled long-acting beta-2 agonists (LABA) are supplementary therapies.

An Oral asthma agent - montelukast

• Montelukast is an example of an oral leukotriene receptor antagonist to help control asthma symptoms.

Leukotrienes

• Leukotrienes are inflammatory molecules that exacerbate asthmatic reactions.
• Leukotriene receptor antagonists (LTRA) block leukotriene receptors, reducing inflammation and bronchoconstriction.

Montelukast – A Leukotriene Receptor Antagonist

• This type of drug blocks the effects of leukotrienes, which contribute to the allergic inflammatory response.
• The reduction in immune response causes an improvement in airways inflammation.
• Common side-effects include gastrointestinal issues.

Long acting β2-adrenoceptor agonists (LABA)

• Formoterol and salmeterol act more slowly than SABAs, with a sustained action.

Maintenance and Reliever Therapy (MART)

• Combining inhaled corticosteroids with long-acting beta-2 agonists provide a combination therapy for effective asthma control.

Additional Controller Therapies

• Long-acting muscarinic antagonists (LAMAs) and theophylline are added when additional control is needed.

Long-acting muscarinic receptor antagonist (LAMA)

• Tiotropium is an example of a LAMA, which is given as an inhaled solution to block the effects of acetylcholine and improve airways function.

Theophylline

• A bronchodilator/respiratory stimulant.
• Can saturate liver metabolism.
• Extended-release formulation helps with twice daily dosing.
• Potential side effects include convulsions and arrhythmias.

Step 5: Continuous corticosteroid (oral)

• Oral corticosteroids, like prednisolone, reduce inflammation and suppress the immune system.
• Prednisolone is an example of a glucocorticoid.

Prednisolone

• Lipocortins are produced in reaction to inflammatory responses, thereby being produced in response to asthma inflammation.
• Prednisolone's mechanisms include inhibition of lipocortin production resulting in reduced inflammation.
• Prednisolone also is an immunosuppressant, leading to complications such as decreased IL-2 production and T-cell expansion.

Adverse Effects : Glucocorticoids

• Glucocorticoids, such as prednisolone, have side-effects, including euphoria, depression, thinning of the skin, buffalo hump, increased abdominal fat.
• Important side-effects include osteoporosis, tendency to hyperglycaemia, negative nitrogen balance, increased appetite, increased risk of infection and obesity.

Adrenal Suppression

• Steroid treatment can cause adrenal suppression if not withdrawn gradually.

Severe Asthma and The Eosinophil

• Severe asthma can be characterized by severe breathlessness issues.
• Asthma can be triggered by eosinophils, which are white blood cells that play a role in inflammation.

Interleukin IL-5 Inhibitors

• These drugs target IL-5, a substance that plays a critical inflammatory role.
• Monoclonal antibodies, such as mepolizumab or reslizumab, block IL-5 activity.

Major drugs to remember for the treatment of Asthma

• Salbutamol, Beclometasone, Montelukast, Salmeterol, Tiotropium, Theophylline, Prednisolone, Mepolizumab are key drugs in asthma treatment.

Summary : Drug Treatment of Asthma

• This provides summarized information of drug treatments including their mechanisms and typical treatments of asthma.

Test your knowledge on asthma treatment pharmacology, focusing on short-acting β2-adrenoceptor agonists, leukotriene receptor antagonists, and corticosteroid therapies. This quiz covers various mechanisms of action, adverse effects, and latest therapeutic approaches in managing asthma. Evaluate your understanding of essential asthma medications and their applications.