3. Respiratory system

Question 1

Antimuscarinic Bronchodilators

Ipratropium (Atrovent) and Tiotropium (Spiriva)

Answer 1

Indications - COPD and life threatening asthma
S/E - Dry mouth, there are less S/E because the drugs are been inhaled
Warnings - Use with caution in patients with angle-closure glaucoma
Dose
Short acting antimuscarinics (Ipratropium) are prescribed QDS or PRN
Long acting antimuscarinics (Tiotropium) are generally prescribed OD

Question 2

Theophylline

Theophylline (Slo-Phyllin and Uniphylline)

Answer 2

Indications - Severe acute asthma and COPD
S/E -Gastric irritation, diarrhoea, palpitations, tachycardia, arrhythmia, headache, CNS stimulation and convulsions. Arrhythmia and convulsions are signs of toxicity.
Warnings - Use with caution in patients with CVD, arrhythmia, high blood pressure, hyperthyroidism, peptic ulcer, epilepsy, elderly, fever and hypokalaemia.
Interactions - The plasma conc is increased in heart failure, hepatic impairment, viral infection, in the elderly and by drugs that inhibit its metabolism (eg Quinolone, Cimetidine and Fluconazole)

The plasma conc is decreased in smokers, by alcohol consumption and by drugs that induce its metabolism (eg St. John’s wort and Rifampicin)

A narrow therapeutic index of 10-20mg/L.

Rx - Theophylline must be prescribed by brand

Communication
Patients should be vigilant for signs of toxicity such as tremor, palpitations, nausea and CNS stimulation and Patients should avoid excess caffeine.

Question 3

Inhaled Corticosteroids 
Buclometasone (Clenil Modulite and Qvar), Budesonide (Pulmicort) 
and Fluicasone (Flioxtide)

Answer 3

Indications - Asthma and COPD
S/E -Oral candidiasis, hoarseness and there is an increased risk of pneumonia
Warnings -High doses should be used with caution in COPD patients with a history of pneumonia and in children where there is a potential for growth suppression.
Rx -Always prescribe by brand
Administration -The potential for paradoxical bronchospasm (calling for discontinuation and alternate therapy) should be borne in mild. Mild bronchospasm can be avoided by the inhalation of a short acting beta-2 agonist before hand.
Communication - Corticosteroid inhalers must be used regularly for maxim benefit. Rinse their month and gargle after use to prevent getting a sore mouth and hoarse voice

Question 4

Antihistamines
Non-sedating - Cetirizine, Loratadine and Fexofenadine
Sedating - Chlorphenamine (Piriton) and Promethazine (Phenergan)

Answer 4

Indications - Allergies, Itchiness, hives,
Anaphylaxis, Nausea and vomiting
S/E - Sedation but the newer ones do not cross the blood brain barrier, so they tend not to have this effect. Older antihistamines may also cause headaches, psychomotor impairment and antimuscarinic effects.
Warnings -Sedating antihistamines should be used with caution in patients with prostatic hypertrophy, urinary retention and angle closure glaucoma due to their antimuscarinic effects. Children are more susceptible to S/E and some are C/I in porphyria.
Communication
Patients taking sedating antihistamines should be advised that their ability to drive or operate machinery may be impaired. The sedation will be enhanced by alcohol.
Non-sedating antihistamines rarely affect skilled tasks in this way but patients should be advised to exercise caution

Question 5

Selective Beta-2 Agonists
Short acting - Salbutamol (Ventolin) and Terbutaline (Bricanyl) (3-5 hours)
Long acting - Salmeterol (Serevent) and Formoterol (12 hours)
Dose

Answer 5

Dose
Salbutamol 1-2 puffs QDS and Terbutaline 1 puff QDS
Salmeterol 2-4 puffs or 1-2 blisters BD and Formoterol 1-2 puffs BD

Question 6

Theophylline
Theophylline (Nuelin SA, Slo-Phyllin and Uniphylline)
Aminophylline (water soluble salt) for injection
Dose

Answer 6

Dose
Theophylline MR
Nuelin SA 1-2 every 12 hours 
Slo-phylline 250-500mg every 12 hours
Uniphylline continus 1-2 every 12 hours 
Aminophylline (phyllocontin continus) 1-2 BD

Question 7

Selective Beta-2 Agonists
Short acting - Salbutamol (Ventolin) and Terbutaline (Bricanyl)
Long acting - Salmeterol (Serevent) and Formoterol

Answer 7

Indications - Asthma and COPD
S/E - Fine tremors, nervous tension, headache, muscle cramps, palpitation and hypokalaemia
Warnings - Use with caution in patients with CVD, arrhythmia and DM (risk of ketoacidosis)
Communication -If they find themselves needing to use their beta-2 agonist frequently, they should see their GP
Notes -Long acting beta-2 agonists must always be given in combination with inhaled corticosteroids. This is because without the steroid they are associated with a high risk of asthma deaths. Formoterol can be used both for the relief and prevention of asthma attacks.