Nervous System Flashcards
Common indications of SSRIs?
1 - First line in Mild, Moderare-Severe Depression
2 - Panic Disorder
3 - Obsessive Compulsive Disorder
SSRI Mechanism of Action? and how do they differ from Tricyclic antidepressants?
SSRIs inhibit neuronal reuptake of serotonin, thereby increasing its availability for neurotransmission.
They differ from TCA’s because they do not inhibit noradrenaline reuptake. Their efficacy is similar but SSRIs have less side effects
Important adverse effects of SSRIs?
1 - GI upset, appetite and weight distubance. Endocrine effect.
2 - Hypersensitivity and Skin Rash.
- Lower Seizure Threshold!! Hyponatraemia which precipitating confusion, and reduced consciousness especially in elderly. Can also cause Serotonin syndrome: Autonomic Hyperactivity / Altered Mental State and NeuroMuscular Excitation. Neurological effect.
4 - Increased Risk of Bleeding and Prolonged QT interval. Cardiac effect
What does sudden withdrawal of SSRIs cause?
Flu Like withdrawal Symtoms:
Warnings with SSRIs?
Prescribe in caution in Epilepsy and Peptic ulcer Disease.
SSRIs are associated with suicidal thoughts and self harm.
Dose reduction needed in hepatic impairment as metabolised by the liver
Interactions with SSRIs
SSRIs should not be given with ►MAOIs as this can increase synaptic serotonin levels, causing Serotonin Syndrome.
GI protetction should be prescribed with patients taking SSRIs with aspirin or NSAIDs due to an increased risk of GI bleed.
Drugs that prolong QT interval e.g Antipsychotics
Examples of SSRIs
Citalopram (safest)
Fluoxetine
Sertraline
Escitalopram (safest)
Prescription advise on SSRIs
Starting dose is low and once daily. Dose increased according to response.
Communication to patients on Citalopram?
Communication to patients on Citalopram?
- Psycological therapy may offer more long term benefits
- Carry on with drug for at least 6 months after they feel better to stop the depression from coming back (2 years if the depression is recurrent)
- Do not stop taking this medicine suddenly: can cause Tummy upset, flu symtoms and weight loss + sleepyness
- Reduce the dose slowly over 4 weeks
Monitoring for SSRIs?
SSRI Symptoms to be reviewed over 1-2 weeks of starting. If no efect seen at 4 weeks, consider changing the dose o
Common indications of Tricyclic Antidepressants?
Common indications of Tricyclic Antidepressants?
- Second Line Tx to Moderate - Severe Depression
- Treatment of Neuropathic pain (unlicensed)
Mechanism of Action of TCAs?
Mechanism of Action of TCAs?
- Inhibit neuronal uptake of Serotonin and noradrenaline to improve mood and physical symptoms
- Blockade of a wide range of receptors: H1/ σ1 /σ2 / D2
Improtant Adverse effects of TCAs?
Improtant Adverse effects of TCAs?
- Blockade of Antimuscarininc receptors – BCUD: Blurry Vision/ Consitpation/ Urinary Retention/ Dry Mouth. Antimuscarinic effects
- Blockade of Histamine Receptors and Alpha: Sedation and Hypotension
- May Cause Arrhythmias and Prolong QT Interval. Cardiac Effects
- Centrally, may cause convulsions, hallucinations and mania. Central Effects
- Blockade of Dopamine receptors can cause breast changes and sexual dysfunction
- Rarely may cause EPSEs (tremor and dyskinesia)
Any sudden withdrawal can cause flu-like symtoms and GI upset. An overdose can be fatal causing respiratory failure. Respiratory effects
Warnings associated with TCAs?
Warnings associated with TCAs?
- Elderly people with Cardiovascular disease
- Epileptic people
- Constipated individuals / Prostatic Hypertrophy / Raised intra-ocular pressure is all made worse by antimuscarinic effects
Important interactions of TCAs?
Important interactions of TCAs?
- Avoid any class of SSRI
- Avoid MAOIs
- Avoid use with other drugs that cause Antimuscarinic / Sedative / Hypotensive effects of other drugs
Example of TCAs?
Amitriptyline
Lofepramine
Prescription advice in neuropathic pain for Amitriptyline?
Prescription advice in neuropathic pain for Amitriptyline?
Start at Lower dose e.g 10mg at night.
What doe you communicate to the patient on TCA?
What doe you communicate to the patient on TCA?
- Takes a few weeks to reach maximum effect
- Psycological therapy may be better in long term
- Carry on for at least 6 months when feeling better (2 years if its recurrent depression)
- Do not stop suddenly, may cause withdrawal symptoms and sleeplessness, rather, reduce over a 4-week period when time comes to stop treatment
- Discuss side effects at an early stage to encourage them to take it.
Indication for Venlaflaxine and Mirtazapine?
Indication for Venlaflaxine and Mirtazapine?
- Major depression
- Venlaflaxine only for Generalised Anxiety Disorder
Mechanism of Action of Venla and Mirt
Mechanism of Action of Venla and Mirt
Venlafaxine is and Serotonin and Noradrenaline Reuptake inhibitor (SNRI)
Mirtazapine is an antagonist of inhibitory pre-synampic σ2 - adrenoceptors.
Both drugs increase the availability of Monoamines for neurotransmission.
Important adverse effect of Venlafaxine and Mirtazapine?
Important adverse effect of Venlafaxine and Mirtazapine?
- GI Upset ( Dry mouth / Nausea /Change in weight and Diarrhoea or Constipation)
- CNS Effects (Headache / Abnormal Dreams / insomnia / Confusions / Convulsion).
- Serotonin Syndrome
- Venlafaxine Prolongs QT + Increases risk of Ventricular Arrhythmias
- Sudden Withdrawal causes GI upset and Flu Symtoms, and Sleeplesness
Presscription advice on Venlafaxine and Mirtazapine?
General Starting doses are 37.5mg BD for Venlafaxine.
General Starting doses are 15mg OD for Mirazapine, take at ngiht to benefit from its sedative effects
What do we communcate to patients on Venla or Mirt?
What do we communcate to patients on Venla or Mirt?
- Improves symtoms over a few weeks.
- Psycological therapy has long term benefits than drug treatment
- carry on for at least 6 months after you feel better to stop depression from coming back (or 2 years if recurrent)
- Do not stop suddenly
If on Mirtazapine: Watch out for Sore throat or symptoms of infection
Indication and Treatment for Metoclopramide and Domperidone?
Prophylaxis and Treatment of Nausea and Vomiting in a wide array of condiions.