Respiratory Drug Agents

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Transcript Respiratory Drug Agents

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These are drugs that we use respiratory
infections including upper and lower
respiratory infections.
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Any substance capable of reducing the
physiologic and pharmacological effects of
histamine.
Histamine is a bodily substance that performs
many functions.
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CNS transmission
Dilation of capillaries
Contraction of smooth muscles
Stimulation of gastric secretion
Acceleration of the heart rate
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There are two types of cellular receptors for
histamine:
H1 receptor
H2 receptor
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Antihistamines are drugs that directly
compete with histamine for specific receptor ,
for this reason they call antagonists.
H2 antagonists include
Cimetidine
Ranitidine
Famotidine
Nizatidine
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H1 antagonists include
Diphenhydramine
Chlorpheniramine
Terfenadine
Astemizole
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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.
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Work by inhibiting the action of histamine
through out the body.
Prevent stimulation of chemo trigger receptor
zone (CTZ).
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Dry mouth
Drowsiness
Constipation
Impotence
Sedation
Nervousness
Restlessness
Difficulty in urinating
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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.
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It is classified pregnancy category C.
Available in 10mg.
Recommended 10mg/day, given as a single
dose.
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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.
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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.
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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
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Available oral, parentral, and topical
preparations.
25mg-50mg cap oral
12.5mg/5ml syrup
10mg/ml- 50mg/ml injection
1%-2% cream topically
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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.
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Available as 2mg/5ml syrup and 4mg tablets.
It is recommended 4mg in TID, QID.
It is a pregnancy category B.
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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.
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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.
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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.
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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.
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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.
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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
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3. Antitussives
a. Codeine
b. Pholcodeine
c. Noscapine
d. Dextrometrophan
e. Chlophedianol
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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
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There are two main categories of these
agents:
1. Narcotic agents
2. Non-narcotic agents
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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
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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
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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.
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Anti-tissuves are primarily used to stop the
cough reflex, when the cough is nonreproductive and harmful
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Dizziness
Headache
Drowsiness
Dry mouth
Nausea
Vomiting
Constipation
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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.
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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
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Flucor day
1. Paracetamol 250mg
2. Pseudoephedrine 30mg
3. Dextromethorphan
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Kuf-Go
1. Aminophylline
2. Diphenhydramine
3. Ammonium chloride
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Bronchophane
1. Guaiphenesin 50mg
2. Ephedrine HCL 7.5mg
3. Diphenhydramine HCL 5mg
4. Dextromethorphan 4.58mg
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Tussilar
1. Chlorpeniramine maleate 0.080 g
2. Dextromethorphan 0.125g
3. Ephedrine HCL 0.150g
4. Guaiphenesin 1g
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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).
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Bronchodilators can be classified into based
on their mechanism of actions:
1. Beta-agonists
2. Xanthine derivatives
3. Corticosteroids
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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
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3. Selective beta two drugs, which only
stimulate the beta two receptors.
E.g Albuterol (Salbutamol)
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Bronchodilators begins at the speacific
receptors.
stimulating receptors, dilate the airways.
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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
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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
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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.
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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
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Xanthenes are used for prevention and
treatment of asthmatic patients.
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Xanthenes are used as a bronchodilators.
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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.
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They all cause bronchodilation by increasing
the levels of the energy producing substance.
Increase levels of CAMP produce
competitively inhibit phosphodiestrase
enzyme.
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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
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Pregnant women
Lactating women
Children below 2 years
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Pharyngeal irritation
Coughing
Dry mouth
Oral fungal infections
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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.
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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.
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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.
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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.
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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.
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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.
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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)
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Adverse effects include arrhymias,
tachycardia and tremors.
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Treatment: metaproterenol by inhalation until
bronchospasms stop. Treat infection, acid
base electrolyte imbalance.
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