Insomnia Flashcards
1
Q
BZs
Common indications
A
- First line manages of seizures and status epilepticus
- First-line management of alcohol withdrawal reactions
- Sedation for interventional procedures
- Short-term treatment of severe, disabling or distressing anxiety
- Short-term treatment of severe, disabling or distressing insomnia
2
Q
BZs
MOA
A
- The target of BZs is the GABA type A receptors
- GABAa receptor is a chloride channel that opens in response to binding by GABA, the main inhibitory neurotransmitter in the brain
- Opening the channel allows chloride to flow into the cell, making the cell more resistant to depolarisation
- BZs facilitate and enhance binding of GABA to the GABAa receptor. This has widespread depressant effect on synaptic transmission
- The clinical manifestations are: Reduced anxiety, sleepiness, sedation and anticonvulsive effects
- Alcohol acts on the GABAa receptor and in chronic excessive use the patient becomes tolerant
- Aburpt withdrawal can occur so we introduce BZs to more accurately withdraw in a controlled way
3
Q
BZs
Adverse effects
A
- Drowsiness, sedation and coma
- Cardiorespiratory depression (however this is rare) in BZ overdose
- Loss of airway reflexes leads to airway obstructiona and death
- Dependence
- Abrupt withdrawal leads to side effects
4
Q
BZs
Warnings
A
- The elderly are more suspectible to BZs effects
- Avoided in patients with respiratory impairment or neuromuscular disease (Myasthenia gravis)
- They should be avoided in liver failure as they may precipitate hepatic encephalopathy
5
Q
BZs
Interactions
A
- Effects of BZs are additive with other sedating drugs (e.g. opioids, alcohol)
- CYP inhibitors increases the effects of BZs (Amiodarone, diltiazem, macrolides, fluconazole)
6
Q
BZ
communication
A
- When treating insomnia and anxiety, advise patient that pharmacological therapy is only a short-term measure
- Discuss risks of dependence, avoid daily use and only supply max 4 weeks
- Advise not to drive/ operate heavy machinary
7
Q
Z drugs
Zopiclone, Zolpidem
Common indications
A
- Short-term treatment of insomnia which is debilitating or distressing
8
Q
Z drugs
MOA
A
- Z drugs have a similar MOA to BZs, target GABAa receptors
- GABAa is a chloride channel that opens in response to GABA, the main inhibitory neurotransmitter
- Opening channels allows chloride to flow into the cell, making the cells more resistant to depolarisation
- Z-drugs facilitate and enhance binding of GABA to the GABAa receptor
9
Q
Z drugs
Adverse effects
A
- Z drugs cause daytime sleepiness, which may affect abillity to drive or perform complex tasks the day after taking medication
- Rebound insomnia may occur when the drugs are stopped
- Other central nervous system effects include headache, confusion, nightmares and rarely amnesia
- Z drugs are chemically distinct from each other, their adverse effects differ
- Zopiclone can cause taste disturbance, whereas zolpidem more commonly causes GI upset
- Prolonged Z drugs beyond 4 weeks can lead to dependence, with withdrawal symptoms on stopping
- In overdose Z drugs cause drowsiness, coma and respiratory depression
10
Q
Z drugs
Warnings
A
- Z drugs should be used with caution in the elderly, who are often more sensitive to drugs with CNS effect
- They should not be used in patients with obstructive sleep apnoea or those with respiratory muscle weakness or respiratory depression, in whom they may worsen respiratory failure during sleep
11
Q
Z drugs
Interactions
A
- Z-drugs enhance the sedative effects of alcohol, antihistamines and BZs
- They enhance the hypotensive effects of antihypertensive medications
- Z drugs are metabolised by P450-Inh (e.g. macrolides) and so can enhance sedation
- Where as P450-Ind (e.g. phenytoin, rifampicin) can impair sedation
12
Q
Melatonin
Indications
A
- Insomnia (Short term use only)
- Jet lag (Short term use only)
- Insomnia in patients with learning disabilities
13
Q
Melatonin
MOA
A
- The pharmacological mechanism of action in melatonin is believed to be based on its interaction with MT1-, MT2- and MT3 receptors, as these receptors (particularly MT1 and MT2) are involved in the regulation of sleep and circadian rhythms in general.
- Melatonin has a hypnotic/sedative effect and increases the propensity for sleep. Melatonin administered earlier or later than the nocturnal peak in melatonin secretion can, respectively, advance or delay the circadian rhythmicity of melatonin secretion. Administration of melatonin at bedtime (between 22:00 and 24:00 hr) at destination following rapid transmeridian travel (aircraft flight) hastens resynchronisation of circadian rhythmicity from ‘departure time’ to ‘destination time’, and ameliorates the collection of symptoms known as jet-lag that are a consequence of such de-synchronisation.
- NB- Pharmacokinetics- Food with IR melatonin may increase the bioavailability
14
Q
Melatonin
Warnings
A
- Cautioned in autoimmune disease
15
Q
Melatonin
Adverse effects
A
- Drowsiness/ sleepiness
- Headache, dizziness
- abnormal dreams
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