. These are drugs that we use respiratory infections including upper and lower respiratory infections. Any substance capable of reducing the physiologic and pharmacological effects of histamine. Histamine is a bodily substance that performs many functions. CNS transmission Dilation of capillaries Contraction of smooth muscles Stimulation of gastric secretion Acceleration of the heart rate 1. 2. There are two types of cellular receptors for histamine: H1 receptor H2 receptor 1. 2. 3. 4. Antihistamines are drugs that directly compete with histamine for specific receptor , for this reason they call antagonists. H2 antagonists include Cimetidine Ranitidine Famotidine Nizatidine 1. 2. 3. 4. H1 antagonists include Diphenhydramine Chlorpheniramine Terfenadine Astemizole They are greatest value in the treatment of nasal allergies. They are used for palliative therapy of common colds They are used to prevent nausea and vomiting, for motion sickness They reduce nasal, salivary and lacrimal gland secretion. Proved to be safe and effective as sleep aid. Work by inhibiting the action of histamine through out the body. Prevent stimulation of chemo trigger receptor zone (CTZ). Dry mouth Drowsiness Constipation Impotence Sedation Nervousness Restlessness Difficulty in urinating Has the longest half-life (20-60 hrs) Dosed once a day Has very poor ant cholinergic activity. Indicated for the treatment of seasonal variation especially in allergy rhinitis. Cautiously given with a patient who have liver problem. Contraindicated patients with hypersensitivity. It is classified pregnancy category C. Available in 10mg. Recommended 10mg/day, given as a single dose. It is a non-sedating antihistamine drug. Used to relieve symptoms of seasonal allergies, hay fever. Classified pregnancy category B agent. Contraindicated in patient shown hypersensitivity. Available in 10mg tablet. Recommended once a day. Terfenadine was the first non-sedating anti histamine to come available. Has short half life Used to relieve the symptoms of seosonal allergic rhinitis. It is a pregnancy category C. Available only for oral preparation. Terfenadine it self comes 60mg tablet, the combination product contains 60mg of Terfenadine and 120mg of pseudoephedrine. Usual recommended dosage is 60mg twice daily, BID. Diphenhydramine is older and traditional anti-histamine. Has potent of ant cholinergic effect. Classified pregnancy category B agent. Contraindicated for 1. Hypersensitivity 2. Nursing mother 3. Neonates Available oral, parentral, and topical preparations. 25mg-50mg cap oral 12.5mg/5ml syrup 10mg/ml- 50mg/ml injection 1%-2% cream topically Available as 4mg, 8mg, and 12mg tablets. Available as POM or OTC Recommended oral dosage is 4mg ever 4 hrs or 6 hrs, given with a full glass water. It is a pregnancy category C. Available as 2mg/5ml syrup and 4mg tablets. It is recommended 4mg in TID, QID. It is a pregnancy category B. It is a POM drug, available 50mg tablets. Recommended oral adult dosage is 50mg100mg every 4 to 6 hours. Recommended in children for 25mg-50mg ever 6 or 8 hour. Taken half an hour before the travel. It is rated in pregnancy category B. It is an OTC drug available as 1.25mg/5ml syrup and 2.5mg tablet. The recommended adult dosage is 2.5mg every 4 to 6 hour, taken with a full of glass water. It is rated in pregnancy category B. It is a prescription drug available as 25 and 50mg/ml injection, as a 6.25 and 25mg/ml syrup. The recommended adult dosage is 12.5mg and 25mg TID. It is rated pregnancy category C. It is a prescription drug available as 0.67mg/5ml syrup and 1.34mg, 2.68 mg tablets. The recommended oral adult dosage is 1.34mg and 2.68mg TID. It is rated in pregnancy category B agent. Coughing is a normal physiologic function and serves the purpose of removing potentially harmful foreign substance and excessive secretions from the respiratory tract. The cough reflex is stimulated when receptors in bronchi, alveoli, and pleura are stretched. 1. 2. 3. 4. 5. Upper or lower respiratory tract infections. E.g appropriate antibiotics Smoking. E.g cessation of smoking Pulmonary tuberculosis. E.g antitubercular drugs. Asthmatic cough. E.g inhaled beta2 agonist/corticosteroids. Rhinitis. E.g avoidance in precipitating factor, corticosteroids or H1 blockers. 6. Gastroesophageal reflux. E.g H2 blockers, PPI. 7. ACE inhibitor associated cough. E.g losartan, calcium channel blockers. Pharyngeal demulcents a. Lozenges b. Cough drops c. Glycerine d. Linctuses containing syrup 2. Expectorants a. Sodium or potassium citrate b. Potassium iodide c. Guiphenesin d. Ammonium chloride 1. 3. Antitussives a. Codeine b. Pholcodeine c. Noscapine d. Dextrometrophan e. Chlophedianol f. Chlorpheniramine g. Diphenhydramine h. Promethazine 4. Adjuvant antitussives a. Salbutamol b. Terbutalin This causes a signal to be sent to the cough center in the medulla of the brain, which in turn stimulates the cough. Cough can be classified into: 1. Productive cough 2. Non-productive cough There are two main categories of these agents: 1. Narcotic agents 2. Non-narcotic agents Narcotic agents have anti-tissuve effects. They are effective in suppressing the cough reflex. They are POM drugs. Their use lead dependence 1. Codeine 2. Hydrocodeine Non-narcotic antitissuve drugs are less effective than the narcotic ones. They are available either alone or combination with other agents, they are POM drugs. 1. Dextromethorphan 2. Benzonatate The narcotic anti-tissuves codeine and Hydrocodeine suppress the cough reflex through a direct action on this cough center. Non-narcotic drugs suppress the cough reflex by anesthetizing (numbing) and thus keeping the cough reflex from being stimulated in the medulla. Anti-tissuves are primarily used to stop the cough reflex, when the cough is nonreproductive and harmful Dizziness Headache Drowsiness Dry mouth Nausea Vomiting Constipation Dextromethorphan is a non narcotic anti tissuve drug. It is widely used because of safety, nonaddicting and does not cause respiratory depression. It is a pregnancy category C. Adult dose is 10-30mg q4h-q8h It is contraindicated, hypersensitivity, headache and asthma. It is a non narcotic anti-tissuve drug. Anesthetizing or numbs the cough receptor. Available only in a POM. It is a pregnancy category C Adult dose is 100mg TID. It is a very popular narcotic anti-tissuve drug. It is a potentially addictive. Depress respirations and the CNS activity. It is classified pregnancy category C. Adult dose is 10-20mg q4h-q6h. It is contraindicated: 1. Hypersensitivity 2. Respiratory depression 3. Seizure disorders Flucor day 1. Paracetamol 250mg 2. Pseudoephedrine 30mg 3. Dextromethorphan Kuf-Go 1. Aminophylline 2. Diphenhydramine 3. Ammonium chloride Bronchophane 1. Guaiphenesin 50mg 2. Ephedrine HCL 7.5mg 3. Diphenhydramine HCL 5mg 4. Dextromethorphan 4.58mg Tussilar 1. Chlorpeniramine maleate 0.080 g 2. Dextromethorphan 0.125g 3. Ephedrine HCL 0.150g 4. Guaiphenesin 1g These are drugs that are used for the lower respiratory tract infections (LRTI): 1. Asthma 2. Emphysema 3. Chronic bronchitis 4. Chronic obstruction pulmonary disease (COPD). Bronchodilators can be classified into based on their mechanism of actions: 1. Beta-agonists 2. Xanthine derivatives 3. Corticosteroids Beta-agonists are large group of drugs that are commonly used during the acute phase of an asthmatic attack. They are agonists or stimulators of the sympathetic nervous system. There are three types of beta-agonist bronchodilators: 1. Non-selective adrenergic drugs, which stimulate the alpha, beta one (cardiac), and beta two (respiratory) receptors. E.G, epinephrine 2. Non- selective beta adrenergic drugs, which stimulate both beta one and beta two receptors. E.g isoproterenol 3. Selective beta two drugs, which only stimulate the beta two receptors. E.g Albuterol (Salbutamol) Bronchodilators begins at the speacific receptors. stimulating receptors, dilate the airways. It is a commonly used drug in acute asthma attacks. Used for prevention of acute attacks It is a pregnancy category C drug. It is a prescription drug Available 2-4mg tablet, 2mg/5ml syrup, 0.083% solution and 0.5 % concentration solution. Pediatric dose is 0.1mg/kg TID or 2mg Tid or Qid. Adult dose is 2 inhalational q4h-q6h. Available in the forms of: 1. Aerosol 2. Solution 3. Powder Metaproterenol is a synthetic sympathomimetic bronchodilator that stimulates both beta one and beta two receptors. It is classified pregnancy category C. It is available as a POM drug Contraindicated: 1. Hypersensitivity 2. Narrow angle glaucoma Orally it came's as a 10mg/5ml solution, 10mg-25mg tablets. Inhalation 0.65mg per spray Peadtric dosage is 10mg Tid, Qid. Adult dosage20mg Tid, Qid. Epinephrine, ephedrine, ethylnorepinephrine are all beta-agonist bronchodilators, that work by stimulating both beta and alpha receptors. Epinephrine is available with or with out prescription. Subcutaneous 10 microgram/kg/dose Aerosol 0.2mg per inhalational Prn. Xanthenes are natural alkaloids that consists of: 1. Caffeine (stimulant) 2. Theobromine (diuretic) 3. Theophylline Xanthenes are used for prevention and treatment of asthmatic patients. Xanthenes are used as a bronchodilators. Theophylline is the most commonly used drug for all xanthine derivatives as well as all bronchodilators. It is used for chronic respiratory disorders and relief of mild to moderate acute asthma. It is classified in a pregnancy category C. Contraindicated in patients with hypersensitivity. Theophylline is available oral, rectal, parenteral, and topical. Pediatric, usual dose is 2.5 mg/kg in q6h Adult dose is 160mg q6h Dosage forms 1. Capsules 100mg- 200mg 2. Tablets 100,125, 200, 250, and 300mg. 3. Injection 25,2500, 5000mg/ml 4. Suppository 250mg and 500mg. They all cause bronchodilation by increasing the levels of the energy producing substance. Increase levels of CAMP produce competitively inhibit phosphodiestrase enzyme. Corticosteroids are used for in the treatment of chronic asthma for their anti-inflammatory effects which lead to decreased airway obstruction. Corticosteroids are used also for prophylactic in acute attacks. The corticosteroids do this by preventing the release of substances that produce inflammation of lungs. Corticosteroids administered inhalation have an advantage over orally administered corticosteroids in that their action is limited to the topical site of action. Drugs of corticosteroids are: 1. Beclomethasone 2. Dexamethasone 3. Triamcinolone acetonide 4. Flunisolide Pregnant women Lactating women Children below 2 years Pharyngeal irritation Coughing Dry mouth Oral fungal infections Administered by oral and inhalation. Used for the treatment of bronchial asthma. Beclomethasone oral solution or rectal suspension has also been used in the management of inflammatory diseases of the gastrointestinal tract (GIT). The primary sites of Beclomethasone are bronchi and bronchioles. It is rated in a pregnancy category C. Cromolyn is a mast cell stabilizer indicated for the prevention of bronchospasm and bronchial asthmatic attacks. It is classified pregnancy category B agent. Available for both oral and ophthalmic administration as well as nasal and oral inhalation. It is a prescription drug, POM. Available in nasal solution 5.2 mg per metred spray. Ophthalmic solution 4 % Capsule 100mg Adult dose is 5-20mg several times in a day, nasal solution 5.2mg 3-6 times a day. Nedocromil is indicated for the prevention of bronchospasms and bronchial asthma attacks. It is a pregnancy category B agent. Only available as an aerosolized inhaler. It is used for mild to moderate bronchial asthma. It is available only in POM. Adult dose is 14mg per day. ID/CC: A 5 year old male becomes cyanotic and has a cardiorespiratory arrest in the ER. HPI: The child, a known asthmatic, had come to the hospital by ambulance 15 minutes earlier with severe wheezing, intercostal retractions, nasal flaring and marked dyspnea. He was given inhaled corticosteroids. PE: Immediate CPR was given, the patient was intubated, and assisted ventilation was administered. The patient came out of the arrest but then returned to his preadmission state of wheezing and respiratory failure. Labs: CBC: leukocytosis, metabolic acidosis, hypoxemia, and airway obstruction. Discussion: In a severe case of asthma such as this, a preexisting infection is usually the precipitating event. Inhaled steroids have no place in the treatment of an acute attack, as is also the case with sodium cromolyn. IV steroids may be given but may take several hours to take full effect (they block leukotriene synthesis by blocking synthesis of phospholipase A2). Inhaled beta-agonists are the mainstay of acute, emergent therapy (they activate adenyl cyclase and thereby increase Camp which relaxes bronchial smooth muscle) Adverse effects include arrhymias, tachycardia and tremors. Treatment: metaproterenol by inhalation until bronchospasms stop. Treat infection, acid base electrolyte imbalance. THANK YOU…