Tutorial 2,3,4 Questions (Module 2) Flashcards
(9 cards)
Joshua returns to the pharmacy. He found two boxes of antihistamines at home in the medicine cabinet. One product contained the active ingredient fexofenadine, 180 mg per tablet and the other product contained the active ingredient promethazine 25 mg per tablet. Compare and contrast the pharmacological actions of each of these antihistamines and provide a recommendation as to when each antihistamine would be most appropriate for your patient, considering he is a bus driver.
Similarities: Both antihistamines, block H1 receptor (stop histamine release), histamine cant bind and exert its effects, therefore, reduced vasodilation and vascular permeability, reduced SM stimulation and contraction.
Differences: Fexofenadine has a longer half-life than promethazine, fexofenadine is the least likely antihistamine to cause drowsiness while promethazine is found in sedating antihistamines. Promethazine crosses the BBB and affects CNS, causes depression and fatigue.
Recommendation: Recommend fexofenadine as it is suitable for day time use, considering he is a bus driver, it is the best choice. Promethazine is only suitable for night time use, has sedating effects.
While Joshua was in the pharmacy, he also asks for your advice about some ‘allergy eye drops’. You have the following products in the pharmacy: Eyezep® (azelastine), Patanol® (olopatadine) and Opticrom® (cromoglycate) eye drops, which are all indicated for the treatment of allergic conjunctivitis. Compare and contrast their mechanisms of actions and adverse effects.
Azelastine: Antihistamine –> block H1 receptor (stop histamine release), histamine cant bind and exert its effects, therefore, reduced vasodilation and vascular permeability, reduced SM stimulation and contraction. Adverse effects: Hyparemia and cause headaches
Olopatadine: Combination of antihistamine and mast cell stabiliser. Mast cell stabiliser –> prevent release of histamine, inhibit mast cell degranulation and stabilise mast cell by blocking calcium channel regulating by IgE, Block entry of calcium and inhibit histamine release. Adverse effects: Hypareamia
Cromoglycate: Mast cell stabiliser. Adverse effects: burning/stinging of eyes after applying eye drops.
Palak points to a bottle of Livostin® (levocabastine) nasal spray on the shelf behind you and states she has this at home from when she stayed at a house with cats earlier in the year and had a very runny and itchy nose, can she use this rather than purchasing a new Otrivin (xylometazoline) today?
Compare and contrast the pharmacological actions of levocabastine and xylometazoline
Xylometazoline (intranasal decongestant): Stimulates alpha 1 receptor, causes vasoconstriction of SM, reduces congestion, decreases vascular permeability which reduces mucus secretion
Levocobastine (antihistamine): block H1 receptor (stop histamine release), histamine cant bind and exert its effects, therefore, reduced vasodilation and vascular permeability, reduced SM stimulation and contraction
Recommendation: Use otrivin (xylometazoline), it is a better decongestant. Better for her symptoms.
Before Palak leaves she mentions that with the many late nights studying lately she has red eyes sometimes in the morning. Is there a drop she can use for the next couple of days in the morning so she appears awake and not red-eyed for her oral exams? She thinks she had used Zaditen® in her previous cat exposure. You have the following products in the pharmacy: Murine Clear Eyes® (naphazoline), Naphcon A® (naphazoline & pheniramine) and Zaditen® (ketotifen) eye drops. Compare and contrast their mechanisms of actions and adverse effects.
Naphazoline: stimulates alpha 1 receptor, causes vasoconstriction of SM, reduces congestion, decreases vascular permeability which reduces mucus secretion. Adverse effects: Causes rebound congestion
Naphazoline and pheniramine: Stimulates alpha 1 receptor.. (napahazoline). Pheniramine is antihistamine. Block H1 receptor (stop histamine release), histamine cant bind and exert its effects, therefore, reduced vasodilation and vascular permeability, reduced SM stimulation and contraction. Adverse effects: causes rebound congestion, headache and dry mouth
Ketotifen –> used for allergic eyes (antihistamine and mast cell stabilizer): block H1 receptor …. Mast cell stabiliser: Prevent the release of histamine, inhibit mast cell degranulation and stabilise mast cell by blocking calcium channel regulating by IgE, Block entry of calcium and inhibit histamine release. Adverse effects: headache, dry mouth, hyparemia
Gerard asks if he can use the Robitussin® Dry Cough Forte (dextromethorphan) he can see behind you. He is sure his wife has a bottle at home for using when the kids have a cough, and would like to use it if he can.
Compare and contrast pharmacological actions of pholcodine and dextromethorphan and consequently possible interactions
Both OTC antitussive cough suppressants which depress the medullary cough center and stops coughing. Both cause drowsiness.
- Pholcodine is an opioid derivative, binds to opioid mu receptors –> stops cough reflex
- Dextromethorphan interacts with serotonergic receptors, it is a non-selective serotonin-uptake inhibitor. It can be used with someone who is taking anti-depressants (works in the same way)
Use pholcodine as it doesn’t interfere with gerards anti-depressant medication
Gerard is pleased with all the information and advice you are providing and decides, as you have a wealth of knowledge on coughing, to ask you about his wife using Ventolin® for her cough at night. He is quite sure she has occasional asthma and is using for a similar cough after her cold. He is interested in why there are different treatments for a similar situation. Compare and contrast their mechanisms of actions and adverse effects.
Pholcodine is an antitussive cough suppressant and opioid derivative. Binds to opioid mu receptors and stops cough reflex. It also depresses the medullary cough center which stops coughing. Causes drowsiness.
Ventolin is strictly used for asthma, it’s short-acting beta 2 agonist which causes dilation of bronchioles which helps someone breathe when they have asthma. Causes tachycardia and tremors.
Emma looks at the shelf behind you and asks if the other Difflam® lozenge, Difflam® antiinflammatory lozenge with cough suppressant (contains benzydamine hydrochloride, pholcodine and cetylpyridinium) is stronger and therefore a better option for her. Compare and contrast the pharmacological actions of these agents. What would be your advice to Emma?
Difflam lozenge: antibacterial/antiseptic to soothe the throat
Difflam plus (anesthetic and benzydamine):
- COX inhibitor (NSAID) –> benzydamine
- Local anesthetic which blocks sensitive NA+ channels and stops the action potential. Results in a local nerve block which causes numbing of the mouth and the throat
Difflam anti-inflammatory lozenge with cough suppressant:
- Depresses medullary cough center, used for dry and unproductive coughs.
Use difflam plus for Emma as it is best for her symptoms. Need to numb the throat as she said it is extremely painful
George mentions that he did know there was another thing he could buy over the counter for asthma and wants to know if it is any better. You chat with him and realize he is talking about Bricanyl® Turbuhaler. Compare and contrast the pharmacological actions of salbutamol and terbutaline and the dosage forms of these two inhalers
Salbutamol and terbutaline both work the same way, they are both short-acting beta two agonists, act on beta two adrenoreceptors in the lungs which causes bronchodilation and relief of asthma. They also inhibit the release of mediators from mast cells and act on cilia to increase mucus clearance.
Turbuhaler is a breath activated device, will release a dose of medication when you inhale on the mouthpiece. Medication is in a powdered form but you won’t get powdery feeling in the mouth.
Ventolin comes in a metered-dose inhaler. Have to press inhaler and breathe in at the same time. May have to use a spacer to make sure all the medication enters your lungs.
Recommend using Turbuhaler as don’t need a spacer, it has a dose counter so can see how much medication is left. All have to do is breathe, don’t have to press inhaler.
George is also wishing to start taking something for his nasal drip that flares up with allergies. He is considering using Nasonex® (mometasone) which the doctor recommended for when the pollen count is high, however is wondering if he should switch to the Azep® (azelastine) near the Nasonex® on the shelf behind you. Compare and contrast their mechanisms of actions and adverse effects.
Mometasone is an intranasal corticosteroid. It is used as a first-line treatment for allergic rhinitis. It binds to glucocorticosteroid receptors, inhibits pro-inflammatory molecules such as mast cells, basophils, eosinophils, and lymphocytes. Also, reduce the release of mediators such as histamine. This reduces inflammation, mucosal swelling, congestion, and secretion. It can also be used for long periods of time. Adverse effects: nasal irritation, itching, and sneezing.
Azelastine is an intranasal antihistamine. It blocks the H1 receptor (stop histamine release), histamine cant bind and exerts its effects, therefore, reduced vasodilation and vascular permeability, reduced SM stimulation and contraction. Adverse effects: headache, dry mouth
