Aminophylline is a compound of the bronchodilator theophylline with ethylenediamine in 2:1 ratio. The ethylenediamine improves solubility, and the aminophylline is usually found as a dihydrate. Aminophylline is less potent and shorter-acting than theophylline Aminophylline: competitive nonselective phosphodiesterase inhibitor which raises intracellular cAMP, activates PKA, inhibits TNF-alpha and leukotriene synthesis, and reduces inflammation and innate immunityand nonselective adenosine receptor antagonist.
Reference ranges of theophylline in the treatment asthma vary by age, as follows: Adults: 5-15 µg/mL Children: 5-10 µg/mL The reference range of theophylline in the treatment of acute bronchospasm in adults is 10-15 µg/mL. The reference range of theophylline in the treatment of neonatal apnea is 6-11 µg/mL.
PUD: peptic ulcer disease
Pharmacology of Respiratory Diseases
Pharmacology of Respiratory
Prepared by: Dr. Hassan Al-Tomy
Reviewed and presented by: Dr. Muna Oqal
Recurrent and reversible shortness of breath
Occurs when the airways of the lungs become
narrow as a result of:
– Inflammation of the bronchial mucosa
– Edema of the bronchial mucosa
– Production of viscid mucus
Alveolar ducts/alveoli remain open, but airflow
to them is obstructed
– Difficulty breathing
Aerosol delivery of drugs
– Should produce a high local concentration in the
lungs with a low systemic delivery → minimizing
– Size of the particles: critical determinant
• >10 um – deposited in the mouth & Oropharynx
• <0.5 um – inhaled, subsequently exhaled
• 1-5 um – allow deposition & most effective
• Plant alkaloids: caffeine, Theobromine, and
• Only Theophylline is used as a bronchodilator
• Contraindications: history of PUD or GI disorders
• Cautious use: cardiac disease
• Timed-release preparations should not be
crushed or chewed (causes gastric irritation)
• Large group, sympathomimetic.
• Used during acute phase of asthmatic attacks.
• Quickly reduce airway constriction and restore
• Stimulate beta2-adrenergic receptors throughout
• Nonselective adrenergics
– Stimulate alpha-, beta1- (cardiac), and beta2- (respiratory)
– Example: epinephrine
• Nonselective beta-adrenergics
– Stimulate both beta1- and beta2-receptors
– Example: Isoproterenol
• Selective beta2 drugs
– Stimulate only beta2-receptors
– Example: Salbutamol
Beta-Agonists: Mechanism of Action
• Begins at the specific receptor stimulated.
• Ends with the dilation of the airways.
– relaxes smooth muscles of the airway and results
in bronchial dilation and increased airflow
• Relief of bronchospasm related to asthma, bronchitis,
and other pulmonary diseases.
• Useful in treatment of acute attacks as well as
• Used in hypotension and shock.
• Used to produce uterine relaxation to prevent
• Hyperkalemia—stimulates potassium to shift into the cell
Beta-Agonists: Side Effects
• Hypotension OR hypertension
• Vascular headaches
• Monitor for therapeutic effects
– Decreased dyspnea.
– Decreased wheezing, restlessness, and anxiety.
– Improved respiratory patterns with return to normal rate and
– Improved activity tolerance.
• Decreased symptoms and increased ease of breathing.
• Salbutamol, if used too frequently, loses its beta2-
specific actions at larger doses.
• As a result, beta1-receptors are stimulated,
causing nausea, increased anxiety, palpitations,
tremors, and increased heart rate.
Mechanism of Action
• Acetylcholine (ACh) causes bronchial constriction
and narrowing of the airways.
• Anticholinergics bind to the ACh receptors,
preventing ACh from binding.
• Result: bronchoconstriction is prevented, airways
• Ipratropium (Atrovent) and Tiotropium
• Slow and prolonged action
• Used to prevent bronchoconstriction
• Dry mouth or throat
• Gastrointestinal distress
• Also called leukotriene receptor antagonists
• Newer class of asthma medications
• Three subcategories of agents.
• Leukotrienes are substances in the body that
cause inflammation, bronchoconstriction, and
• Result: coughing, wheezing, shortness of breath.
Currently available agents
– montelukast (Singulair)
– zafirlukast (Accolate)
– zileuton (Zyflo)
Mechanism of Action
– Prevent inflammation in the lungs so asthma symptoms
• Prophylaxis and chronic treatment of asthma in
adults and children older than age 12.
• NOT meant for management of acute asthmatic
• Montelukast (Singulair) is approved for use in
children ages 2 and older.
• Used for chronic asthma.
• Do not relieve symptoms of acute asthmatic attacks.
• Oral or inhaled forms.
• Inhaled forms reduce systemic effects.
• May take several weeks before full effects are seen.
Mechanism of Action
• Stabilize membranes of cells that release harmful
• These cells are leukocytes, or white blood cells.
• Also increase responsiveness of bronchial smooth
muscle to beta-adrenergic stimulation
• Treatment of bronchospastic disorders that are
not controlled by conventional bronchodilators.
• NOT considered first-line agents for management
of acute asthmatic attacks or status asthmaticus
• Pharyngeal irritation
• Dry mouth
• Oral fungal infections
• Systemic effects are rare because of the low
doses used for inhalation therapy
• Cautious use in patients with diabetes, glaucoma,
osteoporosis, PUD, renal disease, HF, edema.
• Teach patients to gargle and rinse the mouth with
water afterward to prevent the development of oral
Mast Cell Stabilizers (cont'd(
• Indirect-acting agents that prevent the release of the
various substances that cause bronchospasm.
• Stabilize the cell membranes of inflammatory cells (mast
cells, monocytes, macrophages), thus preventing release
of harmful cellular contents.
• No direct bronchodilator activity.
• Used prophylactically.
Mast Cell Stabilizers:
• Adjuncts to the overall management of asthma.
• Used solely for prophylaxis, NOT for acute asthma
• Used to prevent exercise-induced bronchospasm.
• Used to prevent bronchospasm associated with exposure
to known precipitating factors, such as cold, dry air or
Other Respiratory Agents
- reduce the thickness and stickiness of purulent and non-purulent
- antidote for paracetamol poisoning
- act by regulating and normalizing the viscosity of secretion from
the mucus cell of respiratory tract
- decrease the size and number of mucus producing cells
- depolymerization of mucopolysaccharides, direct effect on
- liberation of lysosomal enzymes producing cells which digest