1

What are the pharmacological properties of salbutamol?

Class of drug: β2 adenoreceptor agonist.

Mechanism of action: salbutamol is a short-acting agonist of β2 adenoreceptors in bronchial smooth muscle, resulting in bronchodilation.

Indications: bronchospasm, asthma, chronic obstructive pulmonary disease.

Cautions: hyperthyroidism, cardiovascular disease, arrhythmia, hypertension, diabetes (risk of ketoacidosis).

Side effects: tremor, palpitations, headache, myocardial ischaemia.

Dose:

a)

metered dose inhaler (200μg/puff) 2 puffs PRN;

b)

nebulised solution 2.5-5mg, up to 2-hourly if necessary;

c)

intravenous infusion 3-20μg/min.

2

What are the pharmacological properties of ipratropium?

Class of drug: anticholinergic drug.

Mechanism of action: ipratropium is a short-acting antagonist of muscarinic acetylcholine receptors in bronchial smooth muscle, resulting in bronchodilation.

Indications: bronchospasm, asthma, chronic obstructive pulmonary disease.

Cautions: prostatic hyperplasia, bladder outflow obstruction, angle closure glaucoma.

Side effects: dry mouth, constipation, cough, urinary retention.

Dose:

a)

metered dose inhaler (Atrovent^®, 20μg/puff) 1-2 puffs o.d. or b.d.;

b)

nebulised solution 250-500μg q.d.s.

3

What are the pharmacological properties of theophylline?

Class of drug: xanthine derivative.

Mechanism of action: theophylline is a competitive, non-selective phosphodiesterase inhibitor and a non-selective adenosine receptor antagonist, resulting in bronchodilation, positive inotropy, positive chronotropy and renal vasodilation.

Indications: bronchospasm, asthma, chronic obstructive pulmonary disease.

Cautions: arrhythmia, epilepsy, hypokalaemia.

Side effects: palpitations, convulsions.

Dose:

a)

250-500mg b.d. PO;

b)

aminophylline 100μg/kg/hr IV.

4

What are the pharmacological properties of prednisolone?

Class of drug: synthetic corticosteroid.

Mechanism of action: prednisolone suppresses the inflammatory response by modulating the expression of a variety of pathways (including cyclo-oxygenase-2 [COX-2], cell adhesion molecules, cytokines and inducible nitric oxide). This is achieved by irreversibly binding to alpha- and beta-glucocorticoid receptors (GR), which are present on almost all cells.

Indications: immune suppression in COPD, asthma and transplantation.

Cautions: Cushing’s syndrome, hyperglycaemia.

Side effects: fluid retention, Cushing’s syndrome, hyperglycaemia, osteoporosis, gastrointestinal bleeding, steroid psychosis, pancreatitis.

Dose: usually 0.5-1mg/kg/day PO followed by a tapering regime depending on clinical status.

5

What are the pharmacological properties of carbocysteine?

Class of drug: mucolytic agent.

Mechanism of action: increases the sialomucin content of bronchial secretions, resulting in reduced viscosity of sputum. Sialomucin is also believed to reduce bronchial oedema and spasm.

Indications: COPD, bronchiectasis, acute sputum retention postoperatively.

Cautions: peptic ulcer disease, concomitant use with cough suppressants.

Side effects: gastrointestinal bleeding, nausea, dry mouth, rash.

Dose: 375-750mg t.d.s. PO.

6

What are the pharmacological properties of DNAse?

Class of drug: mucolytic agent.

Mechanism of action: deoxyribonuclease (DNAse) is an enzyme that depolymerises DNA that has been released during the breakdown of leukocytes. It is effective in reducing the viscosity of sputum in cystic fibrosis patients. It can also reduce the viscosity of empyema fluid.

Indications: cystic fibrosis patients (with an FEV₁ > 40%), empyema.

Cautions: patients with an inability to clear their own secretions.

Side effects: (rare) dyspepsia, chest pain, dysphonia, pyrexia, rash, conjunctivitis, laryngitis.

Dose: 2.5mg o.d. via jet nebuliser.

7

What are the pharmacological properties of paracetamol (acetaminophen)?

Class of drug: analgesic.

Mechanism of action: believed to act at several different receptor sites, including COX-2 inhibition, blockade of transient receptor potential A1 (TRPA-1) receptors in the dorsal horn and modulation of the endogenous cannabinoid system, resulting in analgesic, anti-pyretic and anti-inflammatory effects. When administered intravenously, its potency is believed to be equivalent to that of morphine.

Indications: pain, fever.

Cautions: liver failure.

Side effects: very rare. Prolonged use may result in renal dysfunction, hepatic dysfunction or gastritis.

Dose: 500-1000mg q.d.s. PO or IV.

8

What are the pharmacological properties of non-steroidal anti-inflammatory drugs (NSAIDs)?

Mechanism of action: non-selective cyclo-oxygenase inhibitors, affecting both COX-1 and COX-2 isoenzymes, with analgesic, anti-pyretic and anti-inflammatory effects.

Indications: pain, fever, rheumatoid arthritis, osteoarthritis.

Cautions: gastritis, peptic ulcer disease, risk of renal failure if used concomitantly with aspirin or an angiotensin-converting enzyme (ACE) inhibitor.

Side effects: gastrointestinal ulceration and bleeding, renal dysfunction, exacerbation of asthma symptoms.

Dose:

a)

ibuprofen 200-400mg t.d.s. PO;

b)

voltarol 50-75mg t.d.s. PO.

9

What are the pharmacological properties of cyclo-oxygenase 2 (COX-2) inhibitors?

Mechanism of action: non-steroidal anti-inflammatory drug that selectively inhibits the cyclo-oxygenase 2 enzyme.

Indications: short-term management of acute postoperative pain.

Cautions: ischaemic heart disease, cerebrovascular disease, peripheral arterial disease, mild-moderate heart failure and gastrointestinal bleeding are contraindications. Rofecoxib was withdrawn from the market due to an increased incidence of myocardial infarction and stroke following high-dose usage. Selective COX-2 inhibitors must be used with caution in patients with a history of heart failure, left ventricular dysfunction and hypertension.

Side effects: gastrointestinal bleeding and ulceration, renal impairment, fluid retention, hypersensitivity.

Dose:

a)

parecoxib:

i)

IV: 40mg initial bolus followed by 20-40mg q.d.s.;

ii)

PO: no oral dose;

b)

celecoxib:

i)

IV: 40mg initial bolus, then 20-40mg q.d.s. PRN for up to 3 days;

ii)

PO: 400mg initial bolus, then 200mg b.d.

10

What are the pharmacological properties of opiates?

Mechanism of action: opiates and their derivatives act on mu-opioid receptors in the central nervous system, producing analgesic and some sedative effects.

Indications: severe pain.

Cautions: existing respiratory depression, urinary retention, bowel obstruction, ileus and biliary colic are relative contraindications.

Side effects: respiratory depression, constipation, addiction, tolerance, withdrawal syndrome.

Dose:

a)

morphine PO:

i)

oxycodone 10-20mg b.d.;

ii)

oxynorm or oramorph 5-10mg q.d.s. PRN;

iii)

morphine sulphate (MST) (palliative care) 30mg b.d. and titrate upwards;

b)

morphine patient-controlled analgesia (PCA): 1mg/mL, 1mg demand bolus with 5-minute lockout;

c)

codeine PO: 30-60mg q.d.s.;

d)

fentanyl:

i)

PCA: 50μg/mL, 1mL demand bolus with 5-8-minute lockout;

ii)

IM: 50-100μg, every 1-2 hours.

11

What are the pharmacological properties of lignocaine?

Class of drug: local anaesthetic; Vaughan-Williams Class 1b anti-arrhythmic.

Mechanism of action: short-acting blockade of fast sodium channels.

Indications: local anaesthetic for surface infiltration; anti-tussive (if delivered endobronchially below the vocal chords); ventricular dysrhythmias.

Cautions: heart block, concomitant Class I anti-arrhythmic agents; hypotension.

Side effects: well tolerated but if inadvertently administered intravenously, lignocaine may cause central nervous system (CNS) excitation (seizures, blurred vision, dizziness) and then CNS depression (drowsiness, respiratory depression, loss of consciousness). Cardiovascular effects include hypotension and bradyarrhythmias. CNS signs may occur at lower systemic concentrations than cardiovascular effects.

Dose:

a)

local anaesthetic – maximum dose 3mg/kg SC (lignocaine without adrenaline);

b)

local anaesthetic – maximum dose 7mg/kg SC (lignocaine with adrenaline);

c)

cardiac arrest (ventricular tachycardia refractory to DC cardioversion) – 1mg IV.

12

What are the pharmacological properties of cisplatin?

Class of drug: platinum-based chemotherapeutic agent.

Mechanism of action: cross-linking DNA during replication, thereby triggering intrinsic apoptotic pathways.

Indications: lung cancer (non-small cell lung cancer [NSCLC] and small cell lung cancer [SCLC]), mesothelioma.

Cautions: pregnancy (contraindication), renal impairment (relative contraindication).

Side effects: nephrotoxicity, neurotoxicity, nausea, vomiting, ototoxicity, hypomagnesaemia, hypokalaemia, hypocalcaemia, myelotoxicity, haemolytic anaemia.