obat pada gangguan sistem pernafasan dan astma
DESCRIPTION
OBAT PADA GANGGUAN SISTEM PERNAFASAN dan Astma. Infeksi saluran pernafasan atas (ISPA) termasuk flu, r i nitis akut, sinusitis, tonsillitis akut dan laryngitis akut. Pilek adalah tipe infeksi saluran nafas atas yang paling sering ditemukan. . Saluran Pernapasan. - PowerPoint PPT PresentationTRANSCRIPT
OBAT PADA GANGGUAN SISTEM PERNAFASAN dan Astma
• Infeksi saluran pernafasan atas (ISPA) termasuk flu, rinitis akut, sinusitis, tonsillitis akut dan laryngitis akut.
• Pilek adalah tipe infeksi saluran nafas atas yang paling sering ditemukan.
Saluran Pernapasan
Saluran pernapasan dibagi dalam 2 golongan utama:
1. saluran pernapasan atas, terdiri dari lobang hidung, rongga hidung, faring, laring
2. saluran pernafasan bawah terdiri dari trachea, bronchi, bronchioles, alveoli dan membran alveouler – kapiler
Gangguan Saluran pernafasan () :
Saluran pernafasan atas Jenis-jenis infeksi saluran pernafasan atas :
batuk pilek, faringitis, sinusitis, dan toksilitis.
Saluran pernafasan bawahJenis infeksi saluran pernafasan bawah : asma,
bronchitis kronik, emfizema, bronkioklialis.
Obat Saluran Pernafasan. Antihistaminika.Semua antihistamin memberikan manfaat potensial pada terapi alergi
nasal, rhinitis alergik. Antihistamin mengurangi rasa gatal pada hidung yang menyebabkan penderita
bersin banyak obat-obat flu yang dapat dibeli bebas mengandung antihistamin, yang dapat menimbulkan rasa mengantuk.
AntikolinergikSifat antikolinergik pada kebanyakan antihistamin menyebabkan mulut
kering dan pengurangan sekresi, membuat zat ini berguna untuk mengobati rhinitis yang ditimbulkan oleh flu.
Bronchial Asthma
• Therapeutic management:- Allergic control to prevent attacks.
- Drug therapy:B- adrenergic, Theophyllin, & corticosteroids
preparations + chest physiotherapy (only in between attacks).
Difenhidramin( Benadryl )
• D : PO : 25-50 mg, setiap 4-6 jam• D : PO, IM, IV : 5 mg/kg/h dalam 4 dosis
terbagi, tidak lebih dari 300 mg/hari• D : IM:IV: 10-50 mg dosis tunggal
Batuk Karena Alergi
Klorfenilamin maleat
DWS: PO : 2-4 mg, setiap 4-6 jamAnak: 6-12 thn: 2 mg, setiap 4-6 jamAnak: 2-6 thn: PO, 1 mg, setiap 4-6 jam
Antihistamin lain
• Fenotiasin• Prometazine• Timeprazine
• Turunan piperazinehydroxyzine
MukolitikMukolitik berkerja dengan mencairkan dan mengencerkan secret
mukosa yang kental sehingga dapat dikeluarkan. Efek samping yang paling sering terjadi adalah mual dan muntah,
maka penderita tukak lambung perlu waspada. Wanita hamil dan selama laktasi boleh menggunakan obat ini.
Contoh obat : ambroxol, bromheksin.Dosis:* ambroksol: dewasa dan anak-anak >12 thn, sehari 3 x 30 mg
untuk 2-3 hari pertama. Kemudian sehari 3 x 15 mg.Anak-anak 5-12 thn, sehari 2-3 x 15 mgAnak 2-5 thn, sehari 3 x 7,5 mg (2,5 ml sirop)Anak <2>* bromheksin: oral 3-4 dd 8-16 mg (klorida)anak-anak 3 dd 1,6-8 mg.
InhalasiInhalasi adalah suatu cara penggunaan adrenergika dan
kortikosteroida yang memberikan beberapa keuntungan. Efeknya lebih cepat, dosisnya jauh lebih rendah dan tidak diresorpsi ke dalam darah sehingga resiko efek sampingnya ringan sekali. Dalam sediaan inhalasi, obat dihisap sebagai aerosol (nebuhaler) atau sebagai serbuk halus (turbuhaler).
Inhalasi dilakukan 3-4 kali sehari 2 semprotan, sebaiknya pada saat-saat tertentu, seperti sebelum atau sesudah mengelularkan ternaga, setelah bersentuhan dengan zat-zat yang merangsang (asap rokok, kabut, alergan, dan saat sesak napas).
Contoh obat : minyak angin (aromatis), Metaproterenoldosis: isoproterenol atau isuprel: 10-20 mg setiap 6-8 jam (dewasa).
5-10 mg setiap 6-8 jam.
Kromoglikat
• Kromoglikat sangat efektif sebagai obat pencegah serangan asma dan bronchitis yang bersifat alergis, serta konjungtivitis atau rhinitis alergik dan alergi akibat bahan makanan. ]
Efek samping berupa rangsangan lokal pada selaput lender tenggorok dan trachea, dengan gejala perasaan kering, batuk-batuk, kadang-kadang kejang bronchi dan serangan asma selewat. Wanita hamil dapat menggunakan obat ini.
Contoh obat :• Natrium kromoglikat dipakai untuk pengobatan, pencegahan pada asma
bronchial dan tidak dipakai untuk serangan asma akut. Metode pemberiannya adalah secara inhalasi dan obat ini dapat dipakai
bersama dengan adrenergic beta dan derivat santin. Obai ini tidak boleh dihentikan secara mendadak karena dapat menimbulkan serangan asma.,
Kortikosteroid • Kortikosteroid berkhasiat meniadakan efek mediator, seperti
peradangan dan gatal-gatal. Penggunaannya terutama bermanfaat pada serangan asma akibat
infeksi virus, selain itu juga pada infeksi bakteri untuk melawan reaksi peradangan. Untuk mengurangi hiper reaktivitas bronchi, zat-zat ini dapat diberikan per inhalasi atau peroral.
Penggunaan oral untuk jangka waktu lama hendaknya dihindari, karena menekan fungsi anak ginjal dan dapat mengakibatkan osteoporosis.
• Contoh obat : hidrokortison, deksamethason, beklometason, budesonid.
Antiasma dan BronkodilatorTeofilinTerdapat bersama kofein pada daun the dan memiliki sejumlah
khasiat antara lain spamolitis terhadap otot polos khususnya pada bronchi, menstimuli jantung dan mendilatasinya serta menstimulasi SSP dan pernapasan. Reabsorpsi nya di usus tidak teratur. Efek sampingnya yang terpenting berupa mual dan muntah baik pada penggunaan oral maupun parienteral. Pada overdosis terjadi efek sentral (sukar tidur, tremor, dan kompulsi) serta gangguan pernapasan juga efek kardiovaskuler.
Dosis: 3-4 dd 125-250 mg microfine (retard)Teofilin dapat diberikan dengan cara injeksi dalam bentuk
aminofilin, suatu campuran teofilin dengan etilendiamin.Stimulan adrenoseptor, contoh obat salbutamol, terbutalin sulfat,
efedrin hidroklorida.
Obat-obat batukAntitussiva (L . tussis = batuk) digunakan untuk pengobatan batuk
sebagai gejala dan dapat di bagi dalam sejumlah kelompok dengan mekanisme kerja yang sangat beraneka ragam, yaitu :
Zat pelunak batuk (emolliensia, L . mollis = lunak ), yang memperlunak rangsangan batuk, melumasi tenggorokan agar tidak kering, dan melunakkan mukosa yang teriritasi. Banyak digunakan syrup (thyme dan althea), zat-zat lender (infus carrageen)
Ekspektoransia (L . ex = keluar, pectus = dada) : minyak terbang, guajakol, radix ipeca (dalam tablet / pelvis doveri) dan ammonium klorida (dalam obat batuk hitam, Sehingga mempermudah pengeluarannya ketika batuk.
Mukolotika : asetilsistein, bromheksin, dan ambroksol, zat-zat ini berdaya merombak dan melarutkan dahak ( L . mucus = lender, lysis = melarutkan),
• Zat pereda : kodein, noskapin, dekstometorfan, dan pentoksiferin , obat-obat dengan kerja sentral ini ampuh pada batuk kering yang mengelitik.
• Antihistaminika : prometazin, difenhidramin, dan klorfeniramin. Obat ini dapat menekan perasaan mengelitik di tenggorokan.
• Anastetika lokal : pentoksiferin. Obat ini menghambat penerusan rangsangan batuk ke pusat batuk.
Penggolongan lain dari antitussiva menurut tempat kerja:
• Zat-zat sentral SSP• Menekan rangsangan batuk di pusat batuk (medula),
dan mungkin juga bekerja terhadap pusat saraf lebih tinggi (di otak) dengan efek menenangkan.– Zat adiktif : Doveri , kodein, hidrokodon dan normetadon.– Zat nonadiktif : noskapin, dekstrometorfan, pentoksiferin.
• Zat-zat perifer di luar SSP• Emolionsia, ekspektoransia, mukolitika, anestetika
local dan zat-zat pereda.
Beta1,2 selekstif pada pengobatan astma
Obat Gangguan Saluran Nafas
• GENERIC: Albuterol
• BRAND: Proventil, Ventolin
• CLASS: Sympathomimetic
Albuterol
• Actions1. Agonist for Beta 2 adrenergic receptors; relaxing bronchial
smooth muscle which results in bronchodilation
2. Minimal cardiac side effects
Albuterol
• Indications:1. Treatment of bronchospasm associated with asthma,
chronic bronchitis and emphysema
2. Prevention of exercise-induced bronchospasm
Albuterol
• Contraindications:1. Hypersensitivity to sympathomimetics
2. Cardiac dysrhythmia
3. Tachycardia and tachydysrhythmias
Albuterol
• Adverse Reactions:1. Excessive use may cause paradoxical bronchospasm and
arrhythmias2. Tachycardia, palpitations, angina, PVCs, hypotension, and
hypertension3. Tremors4. Hyperglycemia5. Peripheral vasodilation6. Nervousness7. Nausea/Vomiting
Albuterol
• Precautions:1. Diabetes
2. Hyperthyroidism
3. Cerebrovascular disease
4. Seizure disorders
Albuterol
• Dose:1. 2 inhalations with metered-dose inhaler, q 4-6 hours
2. 3 ml premixed bullet in nebulizer
Albuterol
• Incompatible/Reactions:1. Tricyclic antidepressants/monoamine oxidase inhibitors
(MAOIs), may increase the effect of this drug2. Other sympathomimetics3. Beta blockers inhibit the effects
Albuterol
• Notes:
Onset: 5-15 minutesPeak: 30 minutes – 2 hoursDuration: 3-4 hours
1. Can be delivered by inhaler and nebulizer2. Metabolized in the liver and excreted in the urine
Epinephrine
• BRAND: Adrenalin
• CLASS: Sympathomimetic/Catecholamine
Epinephrine
• Action:1. Direct effect on alpha and beta adrenergic receptor sites2. Effects include:
Alpha: bronchial, cutaneous, renal and visceral arteriolar constrictionBeta 1: positive inotropic and chronotropic actions, increases automaticityBeta 2: bronchial smooth muscle relaxation and dilation of skeletal vasculature
3. Inhibits the release of histamine
Epinephrine
• Indications:1. Cardiac arrest in general2. Ventricular fibrillation3. Asystole4. Pulseless electrical activity5. Infusion for profound hypotension associated with
bradycardias, in combination with other pressors6. Bronchospasm and bronchoconstriction of bronchial
asthma and some forms of COPD7. Anaphylaxis
Epinephrine
• Contraindications:
1. Uncorrected tachydysrhythmias2. Underlying cardiovascular disease or hypertension3. Glaucoma4. Hypersensitivity to catecholamines5. Hypothermia
Epinephrine/Adverse Reactions• Hypertension• Ventricular arrhythmias• Pulmonary edema• Tachycardia• Palpitations• Anxiety• Psychomotor agitation• Nausea/Vomiting• Pupil dilation• Angina
• Nervousness• Headache• Dizziness• Tremors• Hallucinations• Cerebral hemorrhage• Anorexia
Epinephrine
• Precautions:1. Due to the possibility of cardiovascular disease, epinephrine
should be administered with caution in patients over 35 years of age (with respiratory problems or if they are conscious)
2. The patient should be carefully monitored for changes in pulse, blood pressure, and ECG after administration of epinephrine.
3. Because of its strong inotropic and chronotropic effects, epinephrine causes an increased myocardial O2 demand
Epinephrine
• Precautions:4. Hypovolemia (replenish volume first)5. Diabetes mellitus6. Hyperthyroidism7. Prostatic hypertrophy8. Must be protected from light9. Tends to be deactivated by alkaline solutions (sodium
bicarbonate)10. Do not use with MAOIs or tricyclic antidepressants due to
the danger of hypertensive crisis
Epinephrine
• Dose:1. Cardiac dosage: 1:10,000
a. 1 mg q 3-5 minutes (until the heart restarts)b. Intermediate: 2-5 mg q 3-5 minutesc. Escalating: 1 mg – 3 mg – 5 mg; 3 minutes apartd. High: 0.1 mg/kg q 3-5 minutes
2. Infusion: Mix 1 mg in 250 ml and run at 2-10 mcg/min3. Anaphylaxis and Asthma: .1-.5 mg (1:1,000) SQ or IM
Epinephrine• Incompatible/Reactions:1. Potentiates other sympathomimetics2. Patients on MAOIs, antihistamines, and tricyclic
antidepressants may have heightened effects3. Sodium bicarbonate – deactivates epinephrine4. Nitrates5. Lidocaine6. Aminophylline7. Don’t mix the above drugs in the same syringe with epi;
but can use in the same IV line – just flush between meds
Epinephrine
• Notes:
ONSET: Immediate
PEAK: Minutes
DURATION: Several minutes
Isoetharine
• BRAND: Bronkosol, Bronkometer
• CLASS: Sympathomimetic
Isoetharine
• Actions:
1. Beta 2 agonist (slight specificity); relaxes smooth muscle of bronchioles, vasculature, uterus
Isoetharine
• Indications:
1. Relieve bronchospasm associated with asthma, chronic bronchitis, and emphysema
Isoetharine
• Contraindications:
1. Hypersensitivity to sympathomimetics2. Cardiac dysrhythmias3. Tachycardia and tachydysrhythmias
Isoetharine
• Adverse Reactions:1. Dose-related tachycardia, palpitations, tremors,
nervousness, peripheral vasodilation, nausea/vomiting, transient hyperglycemia, life-threatening arrhythmias; multiple excessive doses can cause paradoxical bronchoconstriction
2. Angina3. Hypertension4. Headache, dizziness, anxiety, restlessness, hallucinations
Isoetharine
• Precautions:1. Use with caution in patients with diabetes,
hyperthyroidism, cardiovascular and cerebrovascular disease
2. Seizure disorders3. Isoetharine contains acetone sodium bisulfite; a sulfite that
may cause allergic-type reactions, including anaphylactic symptoms in certain susceptible individuals
Isoetharine
• Dose:
ADULT1-2 inhalations with metered-dose inhaler3-7 inhalations, via hand nebulizer q 4 hours
PEDIATRICNot recommended in children less than 12 years
Isoetharine
• Incompatible/Reactions:
1. Additive adverse effects with other beta agonists
Isoetharine
• Notes:
ONSET: Immediate
PEAK: 5-15 minutes
DURATION: 1-4 hours
Metaproterenol Sulfate
BRAND: Alupent, Metaprel
CLASS: Sympathomimetic
Metaproterenol Sulfate
• Actions:
1. Agonist for Beta 2 adrenergic receptors – acts directly on smooth muscle
Metaproterenol Sulfate
• Indications:
1. Relieve bronchospasm of COPD and Asthma
Metaproterenol Sulfate
• Contraindications:
1. Hypersensitivity to sympathomimetics2. Hyperthyroidism3. Cerebrovascular or cardiovascular disorders4. Tachycardia and tachydysrhythmias
Metaproterenol SulfateAdverse Reactions
• Dose-related tachycardia• Palpitations• Nervousness• Peripheral vasodilation• Excessive use – lethal
arrhythmias, paradoxical bronchospasm
• Hypertension
• Tremors, headache, dizziness, anxiety, hallucinations
• Nausea/vomiting
Metaproterenol Sulfate
• Precautions:
1. History of cardiovascular disease or hypertension2. Seizures
Metaproterenol Sulfate
• Dose:
ADULT:2-3 inhalations, q 3-4 hoursMetered-dose inhaler or nebulizer
PEDIATRICS:Not recommended in children under 12 years
Metaproterenol Sulfate
• Incompatible/Reactions:
1. Beta blockers2. MAOIs, tricyclic antidepressants3. Potentiates other beta agonists
Metaproterenol Sulfate
• Notes:
ONSET: 1 minute
PEAK: 1 hour
DURATION: 1-5 hours with single dose2-5 hours with repeated dose
GENERIC: Terbutaline Sulfate
BRAND: Bricanyl, Brethine
CLASS: Sympathomimetic
Terbutaline Sulfate
• Actions:
1. Beta 2 agonist – has an affinity for beta 2 receptors of bronchial, vascular, and uterine smooth muscle
2. At increased doses, beta 1 effects may occur
Terbutaline Sulfate
• Indications:
1. Relieve bronchospasm associated with asthma, chronic bronchitis and emphysema (prevalent in patients over the age of 40 or with coronary artery disease)
2. Used in-hospital to stop pre-term labor
Terbutaline Sulfate
• Contraindications:
1. Hypersensitivity to sympathomimetics2. Cardiac dysrhythmias3. Tachycardia and tachydysrhythmias4. Glaucoma
Terbutaline Sulfate
• Adverse Reactions:
1. Tachycardia, tremors, palpitations, nervousness and dizziness
2. Angina, PVCs, hypotension, and hypertension3. Headache, anxiety, hallucinations4. Nausea, vomiting5. Bronchospasm
Terbutaline Sulfate
• Precautions:
1. Used with caution to patients with a history of cardiovascular disease or hypertension
2. Seizure disorders3. Thyroid disease4. Diabetes
Terbutaline Sulfate
• Dose:
ADULT:0.25 mg SQ; repeat in 15-20 minutes2 inhalations separated by a 60 second interval with a metered
dose inhaler4mg/7ml nebulizer mix
Terbutaline Sulfate
• Incompatible/Reactions:
1. Alkaline solutions2. Degrades when exposed to light for long periods of time
Terbutaline Sulfate
• Notes:
ONSET: 15 minutes
PEAK: 30-60 minutes
DURATION: 90 minutes – 4 hours
Theophylline Ethylenediamine
• BRAND: Aminophylline
• CLASS: Methylxanthine Spasmolytic
Theophylline
• Actions:1. Beta 2 agonist; directly relaxes bronchial smooth muscle2. Dilates pulmonary and coronary arterioles, decreasing
pulmonary hypertension and increasing coronary blood flow
3. Slight positive chronotropic and inotropic effects4. Strengthens diaphragmatic contractions by affecting
intracellular calcium5. Mild diuretic
Theophylline
• Actions:6. Stimulates CNS vomiting centers7. Respiratory center stimulant8. Stimulates vagal and vasomotor centers in the brain – can
lead to decreased heart rate, vasoconstriction in the brain – depends on CNS or peripheral predominance
Theophylline
• Indications:
1. Relieve bronchospasm associated with asthma, chronic bronchitis, emphysema, and pulmonary edema
2. Management of CHF and pulmonary edema
Theophylline
• Contraindications:
1. Hypersensitivity to xanthene compounds (e.g. caffeine)2. Cardiac dysrhythmias3. Tachycardia and tachydysrhythmias
TheophyllineAdverse Reactions
• Nausea/vomiting• Hypotension• Irritability• Tachycardia• Angina• Flushing• Diarrhea• Increased respiratory rate• Cardiac arrhythmias
• Tremors• Seizures• Palpitations• Hypertension• Anorexia
Theophylline
• Precautions:1. Caution if patient is already taking theophylline-containing
medications2. Caution to patients with a history of cardiovascular disease
or hypertension3. Thyroid disease4. Active peptic ulcer5. Hypotension may occur following rapid administration6. May oppose the effects of beta blockers
Theophylline
• Dose:
ADULT:Loading dose of 6 mg/kg IV infusion over 20 minutesLoading dose of 1 mg/kg IV infusion over 20 minutes if the
patient has had theophylline products in the last 35 hours
Theophylline
• Incompatible/Reactions:
1. Incompatible with most drugs2. Simetidine, propranolol, erythromycin, and troleandomycin
may increase the effects of the drug3. Barbiturates, phenytoin, and smoking may decrease blood
levels4. May increase the effects of anticoagulants
Theophylline
• Notes:ONSET: 15 minutes:PEAK: 30 minutes – 1 hourDURATION: Averages 5 hours
1. Common forms or oral aminophylline include:* Marax * Primatene* Quibron * Slo-Phyllin* Slobid * Somophyllin* Tedral * Theo-Dur
Respiratory Medications
Respiratory meds are used for several purposes, the most obvious is the treatment of asthma. Class includes:
1. Cough suppressants2. Nasal decongestants3. Antihistamines
Antiasthmatic Medications• Asthma has two basic pathophysiologies:1. Bronchoconstriction2. Inflammation• Treatment is aimed to relieve bronchospasm and
decrease inflammation.• Specific approaches are categorized as beta 2
selective sympathomimetics, nonselective sympathomimetics, methylxanthines, anticholinergics, glucocorticoids and leukotriene antagonists.
Beta 2 Specific Agents• Albuterol (Proventil, Ventolin) is the prototype of this class.1. These agents relax bronchial smooth muscle, resulting in
bronchodilation and relief from bronchospasm.2. These agents are first line therapy for acute shortness of
breath.3. Administered via metered dose inhaler or nebulizer.4. Overall, these agents are very safe.
Nonselective Sympathomimetics• Stimulate both beta 1 and beta 2 receptors, as well as alpha
receptors.• Rarely used to treat asthma because they have the undesired
effects of increased peripheral vascular resistance and increased risks for tachycardias and other dysrhythmias.
• Agents include: epinephrine, ephedrine, and isoproterenol• Epinephrine is the only nonselective sympathomimetic in
common use today.
Methylxanthines• CNS stimulants that have additional bronchodilatory
properties.• Used only when other drugs such as beta 2 specific agents are
ineffective.• Possibly block adenosine receptors.• Prototype is theophylline, taken orally.• Aminophylline, an IV medication, is rapidly metabolized into
theophylline and, therefore, has identical effects.• Chief side effects: nausea/vomiting, insomnia, restlessness,
and dysrhythmias
Anticholinergics• Ipratropium (Atrovent) is an atropine derivative given by
nebulizer.• Because stimulating the muscarinic receptors in the lungs
results in constriction of bronchial smooth muscle, ipratropium, a muscarinic antagonist, causes bronchodilation.
• Ipratropium is inhaled, and has no systemic effects.• Has an additive effect when used with beta 2 agonists.• Most common side effect is dry mouth
Glucocorticoids• Anti-inflammatory properties.• Lower the production and release of inflammatory substances
such as histamine, prostaglandins, and leukotrienes, and reduce mucus and edema secondary to decreasing vascular permeability.
• May be inhaled or taken orally, as well as IV.• Prototype of inhaled glucocorticoid is beclomethasone.• Prototype of oral glucocorticoid is prednisone.• Administered as preventative care.
Glucocorticoids• When inhaled they cause few side effects.• Side effects are due mostly to direct exposure on the
oropharynx, and gargling after taking the drug can decrease the side effects.
• Side effects from the IV administrations of methylprednisolone in emergencies are not likely
• Long periods of administration can lead to adrenal suppression and hyperglycemia.
• Another anti-inflammatory agent used is cromolyn (Intal), an inhaled powder.
Glucocorticoids• Cromolyn is the safest of all antiasthma agents.• Only side effects are coughing or wheezing due to local
irritation caused by the powder.• Often used for preventing asthma in adults and children.
Leukotriene Antagonists• Leukotrienes are mediators released from mast cells upon
contact with allergens.• Contribute powerfully to both inflammation and
bronchoconstriction• Can either block the synthesis of leukotrienes or block their
receptors.• Zileuton (Zyflo) is the prototype of those that block the
synthesis of leukotrienes• Zafirlukast (Accolate) is the prototype of those that block their
receptors
DRUGS USED FOR RHINITIS AND COUGH
• Rhinitis: (inflammation of the nasal lining) comprises a group of symptoms including nasal congestion, itching, redness, sneezing, and rhinorrhea (runny nose).
• Allergic reactions or viral infections may cause it• Drugs that treat the symptoms of rhinitis and cold
are commonly found in over-the-counter remedies.• Nasal decongestants, antihistamines, and cough
suppressants are available in prescription medications.
Nasal Decongestants• Nasal congestion is caused by dilated and engorged nasal
capillaries.• Drugs that constrict these capillaries are effective nasal
decongestants.• Main pharmacologic classification in this functional category is
alpha 1 agonists• Alpha 1 agonists may be given either topically or orally• Examples of agents: phenylephrine, pseudoephedrine, and
phenylpropanolamine, (administered in drops or mist)
Antihistamines• Arrest the effects of histamine by blocking its receptors.• Histamine is an endogenous substance that affects a wide
variety of organs systems.• Noted for its role in allergic reaction.• Histamine binds with H1 receptors to cause vasodilation and
increased capillary permeability (vasculature)• In the lungs, H1 receptors cause bronchoconstriction• In the gut, H2 receptors cause an increase in gastric acid
release• Histamine also acts as a neurotransmitter in the CNS.
Antihistamines• Histamine is synthesized and stored in two types of
granulocytes; tissue-bound mast cells and plasma-bound basophils
• Both types are full of secretory granules, which are vesicles containing inflammatory mediators such as histamine, leukotrienes, and prostaglandins, among others.
• When cells are exposed to allergens, they develop antibodies on their surfaces.
• On subsequent exposures, the antibodies bind with their specific allergen.
Antihistamines• Secretory granules then migrate towards the cell’s exterior
and fuse with the cell membrane. Causing them to release their contents.
• Histamines are useful in our immune systems.• When our immune systems overreact do allergies such as hay
fever or cedar fever send us running for the antihistamines• Typical symptoms of allergic reaction include most of those
associated with rhinitis.• Severe allergic reactions (anaphylaxis) may cause hypotension
Antihistamines• Antihistamines are at best only a secondary drug for treating
anaphylaxis.• Just as there are H1 and H2 histamine receptors, there are H1
and H2 histamine receptor antagonists.• Most old antihistamines were H1 receptor antagonists, newer
antihistamines are H2 receptor antagonists.• Chief side effect is sedation (H1), newer generation do not
cause this sedation effect (H2).• First generation medications: alkylamines (chlorpheniramine
[Chlor-Trimeton]), ethanolamines (diphenhydramine [Benadryl])
Antihistamines• Other first generation antihistamines: clemastine (Tavist), and
phenothiazines (promethazine [Phenergan]).• Some antihistamines also have significant anticholinergic
properties: promethazine and dimenhydrinate (Dramamine), used for motion sickness.
• Second generation antihistamines include: terfenadine (Seldane), loratadine (Claritine), cetirizine (Zyrtec, and fexofenadine (Allegra).
• These agents do not cross the blood-brain barrier and therefore do not cause sedation.
Cough Suppressants• Coughing is a complex reflex that depends on functions in the
CNS, the PNS, and the respiratory muscles.• It is a defense mechanism that aids the removal of foreign
particles like smoke and dust.• In general, treating a productive cough is not appropriate, as it
is performing a useful function.• An unproductive cough, usually results from an irritated
oropharynx and can be troublesome.• The three classifications of cough suppressants include one
that is supported by evidence and two that are not.
Cough Suppressants
• Antitussives1. Suppress the stimulus to cough in the CNS.2. This functional class includes two specific pharmacologic
types:a. Opioidsb. Nonopioids
3. Two most common opioid antitussives are codeine and hydrocodone
4. Both inhibit the stimulus for coughing in the brain but also produce varying degrees of euphoria
Cough Suppressants5. The nonopioid antitussives do not have the potential for
abuse.a. Dextromethoraphan b. Diphenhydraminec. Benzonatate (Tessalon)
• Expectorants: intended to increase the productivity of cough
• Mucolytics: make mucus more watery and easier to cough up
• Little data supports the effectiveness of either of these approaches to cough suppression