RESPIRATORY DISORDERS ( ASTHMA ) College of Pharmacy & Nursing School of Pharmacy PHARMACOTHERAPY-1 LAB (PHCY310L) RESPIRATORY DISORDERS ( ASTHMA ) Course Instructor: Dr. Sabin Thomas

Case-1 An 18-year-old man, VB, presents with a history of recurrent episodes of wheeze after walking 200 metres. VB has recently started to go to a gym and his episodes of wheeze have worsened. He goes to see his doctor. He can talk in sentences but his respiratory rate is increased. His peak flow (PEFR) is 420 L/min which is 80% of predicted result. A diagnosis of mild asthma is made. He is started on salbutamol metered dose inhaler (MDI) two puffs when required and beclometasone (Qvar) 50 micrograms twice daily.

1-What is asthma? Asthma is a chronic inflammatory disease affecting the airways. Symptoms are cough, wheeze, a feeling of tightness in the chest and shortness of breath. Asthma is characterised by: 1- Airway obstruction (bronchoconstriction), which is usually reversible either spontaneously or with therapeutic intervention, 2- Airway hyperresponsiveness to a range of stimuli, 3- Inflammation of the respiratory bronchioles due to eosinophils.

2- What are the risk factors for developing asthma 2- What are the risk factors for developing asthma? What risk factors does the patient have? The risk factors for developing asthma are as follows: _ Atopy in a patient, which refers to a group of disorders which include asthma, eczema and hay fever. _ Positive family history. _ Genetic and environmental factors. _ Occupational factors. (_ Non-steroidal anti-inflammatory drugs (NSAIDs) (e.g. aspirin _ Beta-blockers such as propranolol which can cause bronchoconstriction in some patients. _ Atmospheric pollutants (e.g. cigarette smoke, car pollutants, dust). _ Cold air and exercise. This patient has limited risk factors, however recurrent episodes of wheeze and exposure to cold and exercise may have precipitated the attack.  

3-What is the pharmacology of beta2-agonists and inhaled corticosteroids? Beta2-adrenergic agents cause bronchodilation by increasing the levels of cyclic adenosine monophosphate (cAMP) following stimulation of the beta2-receptors in smooth muscle. They act throughout the respiratory tract . Corticosteroids are anti-inflammatory drugs having a complex mechanism of action. They can affect the production of cytokines, leukotrienes and prostaglandins. This affects the production of eosinophils and release of other markers of the inflammatory response.   Short-acting beta2-adrenergic agents are the drugs of choice for the acute management of asthma Longer acting beta2-adrenergic agonists are used in patients with moderate to severe asthma in combination with corticosteroids.

Side effects of oral formulations Side effects of inhaler formulations Compare the side-effects of both Inhaled versus oral formulations of beta 2 –agonists and corticosteroids.       4- Compare the side effects of both inhaled versus oral formulations of Beta2-agonist and corticosteroid ? Side effects of oral formulations Corticosteroid (prednisolone ) beta2-agonists (Salbutamol ) , Osteoporosis, Sodium and water retention tachycardia, palpitations, tremor Potassium and calcium loss restlessness, headache, blushing , Adrenal Suppression, Peptic ulcer dry mouth, hypertension Side effects of inhaler formulations Corticosteroid (Beclomethasone) beta2-agonists (Salbutamol ) Hoarseness, dysphonia tachycardia, palpitations, tremor Candidiasis of mouth or throat restlessness, headache, blushing Throat irritation dry mouth, hypertension

Advantages and disadvantages of salbutamol formulations 5- What formulations of salbutamol and corticosteroids are available and what are the advantages and disadvantages?   d Advantages and disadvantages of salbutamol formulations Intravenous Nebulizer sol Inhaler Tablet 100% Bioavailability, rapid actioin easily be inhaled into the lungs, provide larger dose of medication Medicine goes to the target directly, less side effects convenient to use, accurate dosage Advantages Highly risky if any mistake happened , painful, trained person is required to administer . Difficulty in using it difficulties in swallowing for some group of pt , less bioavailability Disadvantages

Advantages and disadvantages of corticosteroid formulations Continue … Advantages and disadvantages of corticosteroid formulations Intravenous Inhaler Tablet 100% Bioavailability, rapid actioin Medicine goes to the target directly, less side effects convenient to use, accurate dosage Advantages Highly risky if any mistake happened , painful, trained person is required to administer . Difficulty in using it difficulties in swallowing for some group of pt , less bioavailability Disadvantages

Inhalers provide distribution of medication deep into the lungs 6- Why inhaled medications are preferred over oral in treating asthma?   Inhalers provide distribution of medication deep into the lungs Give rapid effects Less side effects

7- Describe how to use an MDI ? Instructions given to the patient are as follows: _ Sit in a comfortable, upright position. _ Remove the cap of the inhaler. _ Shake the inhaler. _ Breathe out and then put the mouthpiece into your mouth and take a deep inhalation, simultaneously pressing the inhaler. _ Hold your breath, then exhale slowly. _ Wipe the mouthpiece and replace the lid. _ The inhaler should be stored in a cool dry place. The essential counselling points should be taken from the inhaler package insert _ If you are to take two puffs, wait half a minute before repeating the steps above.