Useful for bsc & msc Nursing studendets,

1. Decongestants,
Expectorants,
Antitussive and
antihistamines

2. Decongestants are medications that relieve
nasal congestion by narrowing the blood
vessels in the nasal passages, reducing
swelling and congestion.
Indication and uses
• INDICATIONS
• Allergic rhinitis
• Allergies
• Sinusitis
• Eustashian tube dysfuction
• Upper respiratory congestion
CONTRAINDICATION
• Glucoma
• uncontrolled BP
• Heart conditions
• Thyroid problems
• Enlarged prostate
• Diabetes

3. Oral Decongestants
Sympathomimitic Agents
• Ephedrine, Pseudoephedrine, Phenylephrine (less commonly
used).
• Mechanism of Action:
• Oral Decongestants: Pseudoephedrine is a sympathomimetic amine
and works by stimulating alpha-adrenergic receptors on blood
vessels in the nasal mucosa. This stimulation causes
vasoconstriction, reducing blood flow to the nasal passages and
relieving congestion.
• Oral Decongestants:
• Pseudoephedrine: The typical adult dose is 60 mg to 120 mg every 4 to 6
hours, with a maximum daily dose of 240 mg. Pseudoephedrine is available
as oral tablets or capsules.
• Phenylephrine: The typical adult dose is 10 mg every 4 hours, with a
maximum daily dose of 60 mg. Phenylephrine is less commonly used due to
its shorter duration of action compared to pseudoephedrine. It is available as
oral tablets or capsules.

4. Topical Nasal Decongestants
Sympathomimitic agents
• Oxymetazoline and Xylometazoline are also sympathomimetic agents that
act by constricting blood vessels in the nasal mucosa when applied
topically. This action reduces blood flow and swelling, providing relief from
nasal congestion.
• Doses and Routes of Administration:
• Topical Nasal Decongestants (Nasal Sprays/Drops):
• Oxymetazoline: The usual dose is one to two sprays (0.05% strength) in each nostril
every 10 to 12 hours. Do not use for more than 3 to 5 days consecutively to avoid
rebound congestion. Oxymetazoline is available as nasal sprays.
• Xylometazoline: The usual dose is one to two drops (0.1% strength) in each nostril
every 8 to 10 hours. Do not use for more than 3 to 5 days consecutively to avoid
rebound congestion. Xylometazoline is available as nasal drops.
• Phenylphrine
• Epinephrine
• CORTICOSTEROIDS
• SALINE

5. Side Effects
• Incresed Heart rate
• Increased BP
• Nervousness or restlessness
• Insomnia
• Dry mouth and throat
• N&V, Headache
• Rebound Congestion

6. Expectorants and Antitussives
• Expectorants are drugs that are
increase bronchial secretion or
reduce its viscosity, facilitating its
removal by coughing and
enhance the clearance of mucus.”.
Also called as Mucokinetics.

7. Classification
• Sodium or Potassium citrate, Potassium iodide,( Not Used)
Guaiphenesin- 200-400mg qd
• Ivy Leaf extract(herbal)
• MOA— not fully understood –increases the volume and
fluidity of resp. Secretions—effective when taken
adequate amount off water—hydration
• A. Bronchial Secretion Enhancers

8. B. Mucolytics
• Ambroxol hydrochloride-tab. 30mg , 15mg/5ml
• Acetylecysteine 10%-20% Solution nebuliztaion, 200mg/sachet PO
• Carbocysteine tab. 375mg tid, 250mg/5ml syrup
• Bromhexine (Not Used)
• Mechanism of action
• Ambroxol—increases the production and secretion of surfactant –breaks
down acid mucopolysachride fibre of mucus— helps in reduce surface
tension of mucus— less sticky — easier to expel through coughing
• Acetyle Cystein—break disulphide bonds of mucus—reduces viscosity
• These drugs also act as antioxidants— has Anti-inflammatory action

9. Antitussives
• These are drugs that act
in the CNS to raise the
threshold of cough centre
or act peripherally in the
respiratory tract to reduce
tussal impulses, or both
these actions.

10. Classification of Anti tussives
Pharmacokinetics
• 1. Opioid Derivaties
• Codeine 5-10mg/5ml
• Ethymorphine 100-200mg/5ml
Pholcodein 2.5-5ml/5ml
• Well absorbed
• Metabolism-cypp2d6 into active
metabolite morphine,
hydromorphone
• Bioavailability -50%
• Elimination urine
Mechanism of action
• Acting centrally—Mu opioid
recptor medullary cough centre—
also have peripheral action on
cough receptors.— decreases
cough reflexes
• Side effects — sedation,
constipation, addiction

11. 2. Non-opioid antitussives
Pharmacokinetics
• Dextromethorphan 5-20mg/5ml
• Chlophedianol(clofedanol) 5–12mg/5ml
• Noscopine 1.3-15mg/5ml
• Rapidly absorbed
• Liver enzymes
• Half life— 2-4 hrs. And 1-4 hrs for
nascopine
• Bioavailability 30%-
• Elimination throgh bile and urine
Pharmacodynamics
• Nascopine depresses cough by its delta-
opioid receptor agonist
• Dextrometharphan- NMDA, glutamate
and Sigma 1 in the brain— thoughtto
Supression cough reflexes
• Clofedanol binds to sigma 1 receptor in
the brain – anaesthetic, antispasmodic
and antihistamine effects,
• SIDE EFFECTS
• Dizziness, hallucination, confusion and
impaired motor functions.

12. AntiHistamines
• Histamine occur in plants and animal tissue—
component of some genomes and stinging secretion
• Histamines+serotonin+PGs+ Interleaukins+Cytokines are
called Autocoids—local Horomes.
• L-Histidine— Decarboxylase—Histamine
• Responsible for immidiate allergic and inflamatory
reactions
• Play an important role in gastric acid secretion.

13. Receptor Distribution Functions
H1 receptors 1. Airways, intestinal and uterine smooth
muscles
2. Small Blood Vessels
3. Large Blood vessels
1. Contraction
2. Vasodialation
3. Vasocontriction
H2 Receptors 1. Gastric. Glands
2. Blood Vessels Mast Cells
3. Brain, Cardiac muscles
1. Acid Secretion
2. Vasodialation
3. Increases Synapses
H3 receptors 1. Brain
2. Lungs, Spleen Gastric Mucosa and Skin
1. Sedation
2. Reduction of histamine
release
H4 Receptors 1. Eosinophils, mast cells, basophils, CD4 T
cells
1. Chemotaxic Effect

14. Clinical Pharmacological Effect of Histamine
• Aerosol histamine –provocative test of Bronchial Hypersensitivity
• Intra dermal injection for Triple Response(red spot, Edema, Flare) for
the. Involvement of three types of cells— smooth Muscles of blood
vessels, capillary or venular endothelium and sensory nerve endings.
• Histamine causes Bronchoconstriction by hyperactive Neural
responses in asthmatic patients.
• Injection of histamine cause decrease in systolic and diastolic
pressure and increase in heart rate.

15. ANTIHISTAMINES—Histamine Antagonists
First generation Antihistamines
• We’re introduced in 1930s
• Chlorphenarmine I/V, I/M , PO 2-8mg ,2-5mg/5ml
(OTC for Cold)
• Diphenhydramine tab. 15-25mg, PO 10mg/5ml
• Promethazine 5mg/5ml( Anti emetic)
• Hydroxyzine 15-100mg PO
• Cyclizine25-50mg PO(motion sickness)
• Meclizine 25-30mg PO( motion Sickness)
• Cyproheptadine 4mg PO
• Peak Plasma concentration-1-2hrs
• Metabolized CYP3A4
• Half life— 12-15hrs
Second generation Antihistamines
• Introduced in 1980s
• Fexofanadine(allegra)60-180mg PO
• Loratadine 10mg PO
• Desloratadine 5mg PO
• Citrizine 5-10mg PO ( metabololite of hydoxyzine)
• Levocitrizine 5-10 mg PO
• Azelastine 4mg PO, 0.28 mg Intranasally
• Rupatadine 10mg PO
• Peak Plasma concentration-1-8hrs
• Metabolized CYP3A4
• Half life— 10-18hrs

16. Mechanism of action and Uses
• Block the effect of Histamines by reversible competitive antagonist at H1
receptor promotes Anticholinergics effect
• HI antagonists produce effects at muscarinic, cholinoceptor, Alfa-
adrenoceptor, Serotonin and local anaesthetic receptor sites
• Sedation- known as asleep aides
• Anti nausea and anti emetic effect
• Antiparkinsonism effecct
• Anti allergic reactions
• Motion sickness and vestibular disturbances
• Pruritis

17. Side Effects of Anti
Histamines
• Sedation
• CNS depression
• Hypotension
• Cardiac arrhythmias
• Dry mouth, constipation, and
delayed gastric emptying
• Convulsions in children
• Teratogenic effects with some
drugs— malformation in neonates