Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Respiratory > Leukotriene receptor antagonists > Flashcards

Leukotriene receptor antagonists Flashcards

1
Q

What is the general action of leukotriene receptor antagonists (LTRA)?

A

Prevent leukotriene synthesis or activity by blocking it from binding to its receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are leukotrienes?

A

Released by mast cells during an asthma attack

Cause bronchoconstriction

In chronic, more severe asthma case general bronchial hyperractivity is largely caused by eosinophils which are attracted to bronchioles by leukotrienes and also release leukotrienes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which molecules is leukotriene derived from?

A

Arachnoid acid

A precursor of prostaglandins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name the two main LTRA that you should know?

A

Montelukast

Zafirlukast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the typical dose of montelukast in adults and children aged 15 years and older?

A

10mg OD PO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the typical dose of montelukast in children aged 6-14 years?

A

5mg OD PO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the typical dose of montelukast in children aged 6 months to 5 years?

A

4mg OD PO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the typical dose of zafirlukast in adults and children aged 12 years and older?

A

20mg BD PO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Can zafirlukast be used in children younger than 12?

A

Not licensed for use in younger children

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the contraindications for montelukast?

A

No contraindications or cautions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the contraindications for zafirlukast?

A

Hepatic impairment or cirrhosis

Children under 12 until safety information is available

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the cautions for zafirlukast?

A

People with mild renal impairment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the adverse effects of montelukast?

A

Arthralgia

Bruising

Dyspepsia

Excessive thirst

GI upset

Headache

Hyperkinesia (in young children)

Infections

Malaise

Myalgia

Nose bleeds

Nervous system disorders (e.g., dizziness, drowsiness, paraesthesia/hypoesthesia, seizure)

Oedema

Psychiatric disorders

Rash

Thrombocytopenia

Tic

Enuresis in children

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the psychiatric disorders that can be adverse effects of montelukast?

A

Dream abnormalities inc. nightmares

Insomnia

Somnambulism

Anxiety

Agitation inc. aggressive behaviour or hostility

Depression

Psychomotor hyperactivity inc. irritability, restlessness and tremor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the adverse effects of zafirlukast?

A

Arthralgia

Bruising

GI upset

Hepatic disorder - person or their parent/carer should be advised to alert for signs and symptoms of this e.g., persistent nausea, vomiting, malaise or jaundice and to seek medical attention if they develop

Hyperbilirubinaemia

Infections

Insomnia

Malaise

Muscle cramps

Myalgia

Rash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the very rare adverse effects from LTRA? What should done if a person develops them?

A

Systemic eosinophilia

Eosinophilic pneumonia

Clinical features of systemic vasculitis consistent with Churg-Strauss syndrome

LTRA should be stopped if patient develops any of this

17
Q

What are the important drug interactions for montelukast?

A

Phenytoin, phenobarbital and rifampicin - CYP 3A4, 2C8, 2C9 inducers = reduced levels of montelukast

18
Q

What are the important drug interactions for zafirlukast?

A

Aspirin 650 mg QDS + zafirlukast = ~ 45% increased zafirlukast levels

Warfarin + zafirlukast = 35% increase in max prothrombin time

Theophylline + zafirlukast = increased theophylline levels (rare) - monitor theophylline levels in patients on both drugs

Erythromycin + zafirlukast = 40% decreased plasma level of zarfirlukast

19
Q

What are the pharmacokinetics of montelukast?

A

Oral bioavailability = 64%

Protein binding = > 99%

Half-life = 2.7 - 5.5 hours

Metabolism = hepatic via CYP 3A4, 2C8, 2C9

Excretion = exclusively bile and faeces

20
Q

What are the pharmacokinetics of zafirlukast?

A

Oral bioavailability = ?

Protein binding = 99%

Half-life = 10 hours

Metabolism = hepatic

Excretion = Faeces

21
Q

Sources

A

https://cks.nice.org.uk/topics/asthma/prescribing-information/leukotriene-receptor-antagonists/

https://go.drugbank.com/categories/DBCAT000910 (LTRA)

https://www.bmj.com/content/319/7202/90.1

https://go.drugbank.com/drugs/DB00549 (Zafirlukast)

https://go.drugbank.com/drugs/DB00471 (Montelukast)

Respiratory (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions