Salbutamol

Front 1

Type of drug

Back 1

Bronchodilator/ beta2-adrenergenic receptor agonist

Front 2

Define the disease

Back 2

Used in the tx of asthma, bronchospasm and COPD.

Asttma is caused by inflammation of the bronchi. When contact is made with an irritant/ trigger (e.g. dust mites, animal fur, pollen, tobacco smoke, exercise, cold air or chest infections), airways become narrow as the muscles around the bronchi tighten and there is an increase in sticky mucys (phlegm).

Front 3

Parmacokinetics (what the body does to the drug)

Back 3

Absorption
- parenteral/ inhilation
- absorbed into blood through lungs
- large surface area presented by alveolar membrane
Distribution
- binds to beta2-receptors in lungs
Metabolism
- hydrolysed by esterases in tissuevand blood into active compound colterol.
- drug is also conjugatively metabolised to salbutamol 4'-O-sulphate
Extretion
- 72% of inhaled salbutamol excreted in urinevwithin 24 hours
- 28% pulmonary excretion unchanged
- 44% as metabolite

Front 4

Pharmacodynamics

Back 4

- salbutamol stimulates beta2-adrenergenic receptors (prominant receptors in bronchial smooth muscle of lungs)
- stimulation/ binding = activation of enzyme adenyl cyclase which forms cyclic AMP from ATP which causes muscle relaxation
- muscle relaxation because cyclic AMP inhibits phosphorylation of myosin and lowers intrecellular calcium concentrations
- salbutamol also inhibits release of broncho-constrictor mediators e.g. histamine

Front 5

How and why does the drug help to control the disease?

Back 5

Salbutamol relaxes smooth muscle in bronchi = increased size of airways = more oxygen can enter lungs.

Front 6

Oral conditions relating to drug use

Back 6

- xerostomia
- oral candidiasis

Front 7

Management of these oral conditions

Back 7

Xerostomia
- sip water
- sugar free gum
- saliva subsitutes
- etc.
Oral Candidiasis
- HSMW
- antifungals
- use a spacer instead

Front 8

Medical emergencies related to the disease

Back 8

Anaphylaxis/ asthma attack

Signs
- coughing/ wheezing
- short of breath
- cannot finish a sentence in one breath
- syanosis
Symptoms
- tight chest

if pt has own inhaler with them, 2x puffs every 5 mins
if unresponsive IM adrenaline injection 500micrograms for 12+, 300 micrograms 6-12 yrs, 150 micrograms <6yrs

BLS if unconscious

Front 9

Adverse drug reactions associated with the drug/ side effects

Back 9

- xerostomia
- oral candidiasis
- fine tremor
- nervous tension
- headache
- muscle cramps
- palpitations
- tachycardia
- peripheral vasodilation

Front 10

Interactions with other drugs

Back 10

- Tricyclic antidepressants (e.g. amitriptyline, amoxapine, doxepin, clomipramine, desipramibe): increase sympathomimetic effect of salbutamol
- atenolol & propanolol (beta blocker): antagonism, counteracts, opposes salbutamol