4: Central Nervous System
Approved: 1 Sep 2012. Last amended: 25 Aug 2021.
4.1 Hypnotics and anxiolytics
- Anxiety and insomnia should, where possible, be managed by non-pharmaceutical means. Medication should be reserved for severe and disabling cases.
- Benzodiazepines are indicated for the short-term relief of anxiety (2 to 4 weeks) to alleviate acute conditions. Tolerance and dependence can occur after only a few weeks.
- Benzodiazepines should be avoided where there is a history of substance misuse including alcohol.
- To reduce the risk of tolerance and dependence benzodiazepines should be prescribed on an 'as required' basis.
- Refer to BNF (section 4.1) for information on benzodiazepine withdrawal
- There are a number of “good sleep guides” available to view on the internet, which suggest how to achieve and maintain a healthy sleep cycle.
Before a hypnotic is prescribed the underlying cause should be identified and addressed, and realistic sleep requirements should be discussed with the patient.
All hypnotics should be used for the minimum length of time due to the risks of dependence.
Patients who require short term treatment for insomnia during their hospital admission should not routinely be prescribed a hypnotic to continue following discharge.
Melatonin (Circadin® only)
Sleep reversal associated with dementia where hypnotics are not suitable. General & Old Age Medicine Consultant only. Inpatient use only
Benzodiazepines should be prescribed at the lowest possible dose for the shortest possible time due to the risk of dependence.
Diazepam should be used with caution in the elderly. Lorazepam is preferred in these patients.
Some antidepressants are licensed for anxiety: see section 4.3
Conscious sedation for procedures. Use with caution: NPSA Rapid Response Report
See chapter 2.4 (Anxiety with Palpitations, Sweating, Tremors)
4.2 Drugs used in psychoses and related disorders
4.2.1 Antipsychotic drugs
The choice of drug should be made by the patient and healthcare professional together, considering the relative potential of individual antipsychotic drugs to cause extrapyramidal side effects (including akathisia), metabolic side effects (including weight gain) and other side effects (including unpleasant subjective experiences).
Clozapine is restricted to patients who have not responded to two or more antipsychotics (one of which should be an atypical antipsychotic), or who are intolerant of conventional antipsychotics.
In the case of psychotic disorders occurring during the course of Parkinson's disease, olanzapine, quetiapine or sulpiride are preferable, but clozapine can be used when standard treatment has failed.
Clozapine may only be initiated by members of the healthcare team who are registered with Clozaril Patient Monitoring Service (CPMS). The patient and supplying Pharmacist must also be registered with the CPMS.
Full blood counts are required prior to and during clozapine treatment.
Olanzapine (standard formulation)
Quetiapine (standard formulation)
Chlorpromazine and pericyazine
Swallowing problems, compliance issues
Quetiapine (modified release)
Zaluron XL and Biquelle XL are the preparations of choice. Compliance issues or acute titration (after titration phase, consider whether switching to standard preparation is feasible).
For patients where movement disorders, sedation or metabolic syndrome make treatment with other first- or second-generation antipsychotics unfeasible. NICE TA213
Schizophrenia. Senior Psychiatry advice only.
4.2.2 Antipsychotic long acting injections
These preparations may only be initiated on the advice of senior medical staff working in psychiatry.
Please refer to BNF section for advice on equivalent doses of antipsychotic drugs.
depot injection (50mg, 75mg, 100mg) – Patients who are unable to tolerate the recommended preparations listed above
depot injection – Patients who are unable to tolerate the recommended preparations listed above
4.2.3 Antimanic drugs
First-line options for the treatment of acute mania include atypical antipsychotics (particularly olanzepine) or valproate compounds. Occasionally, benzodiazepines are added for short-term use.
126.96.36.199 Acute treatment
Sodium valproate (Episenta®) capsules/granules
- Senior Psychiatry advice only
- Bipolar Disorder (Children): NICE TA292
Lithium must be prescribed by brand name. Patients should remain on the same brand.
Lithium has a narrow therapeutic / toxic ratio and should therefore not be prescribed unless facilities for monitoring serum lithium concentrations are available. Samples should be taken 12 hours after the preceding dose: sample requirements.
Lithium Monitoring Criteria NICE guidance:
- Lithium levels must be measured every 3 months
- Renal function must be monitored every 6 months
- Thyroid function must be monitored every 6 months
A Lithium Record Booklet should be supplied to every patient at initiation.
Lithium citrate liquid
Sodium Valproate (Episenta®) capsules/granules)
Senior Psychiatry advice only
4.3 Antidepressant drugs
Antidepressants have markedly different safety profiles in overdose. Where there are concerns regarding suicide risk the SSRIs are the least toxic in overdose. Of the tricyclic antidepressants, lofepramine is the least toxic.
Antidepressants should not be withdrawn abruptly if the patient has been taken them regularly for 8 weeks or more, unless there is a serious adverse drug reaction.
Care should be taken when switching between antidepressants. Contact Medicines Information for advice (GRH 0300 422 6108, CGH 0300 422 3030)
SSRIs should not be prescribed in children and adolescents unless under the advice of a Child & Adolescent Mental Health Consultant.
4.3.1 Tricyclic and related antidepressant drugs
In general, SSRIs are the first-line choice for the treatment of depression.
Tricyclics should not be used to treat depression in patients over 75 years old.
4.3.2 Monoamine-oxidase inhibitors
In general, SSRIs are the first-line choice for the treatment of depression.
Specialist use only
Specialist use only
Specialist use only
4.3.3 Selective serotonin re-uptake inhibitors (SSRIs)
Where there is mixed depression and anxiety, citalopram may be considered first line.
SSRIs may initially increase anxiety levels and it may be necessary to ‘cover’ their initiation with a brief course of a benzodiazepine in order to encourage compliance.
Abrupt withdrawal of SSRIs should be avoided (associated with headache, nausea, paraesthesia, dizziness and anxiety).
Withdrawal syndrome is reported to the CSM more commonly with paroxetine than with other SSRIs.
Second-line when citalopram not tolerated
(long half life; may be beneficial in patients with concordance issues)
Third-line as an option for treating major depressive episodes in adults whose condition has responded inadequately to 2 antidepressants within the current episode, as per NICE TA367
4.3.4 Other antidepressant drugs
Gloucestershire Local Guideline: Venlafaxine MR versus IR (immediate release)
Venlafaxine may be considered if a patient fails on another antidepressant or in severe depression.
BP monitoring is advisable for doses of venlafaxine above 200mg daily.
Mirtazapine may be useful for treating depression in patients with reduced appetite.
(Should be prescribed as standard release tablets whenever possible – see local guidance above. If an MR formulation is required, this should only be prescribed as MR tablets)
4.4 Central nervous system stimulants and other drugs used for attention deficit hyperactivity disorder
- Only to be initiated by a specialist experienced in managing ADHD. Shared Care Guideline (intranet)
- Note: Xaggitin XL is the preferred brand of methylphenidate MR (where an 18mg, 27mg, 36mg or 54mg dose is required).
only to be initiated by a specialist experienced in managing ADHD. Shared Care Guideline (intranet)
Consultant child and adolescent Psychiatrist prescribing only. Second line. Shared Care Guideline (intranet)
refer to BNF for indications
Second-line to atomoxetine where a non-stimulant option for ADHD is required but atomoxetine is not tolerated or ineffective
4.5 Drugs used in the treatment of obesity
Pharmacological management of obesity should be initiated in primary care as an adjunct to other lifestyle measures.
Treatment must be reviewed regularly to ensure that required weight loss is being achieved. See BNF for details.
As per NICE TA664
4.6 Drugs used in nausea and vertigo
4.6.1 General and post-operative nausea and vomiting (PONV)
note: cyclizine injection is expensive, only use where ondansetron injection is unsuitable
4.6.2 Cytotoxic chemotherapy
GHNHSFT: Refer to OPMAS electronic prescribing system
Granisetron patch (Sancuso®)
patients for whom there is concern about the absorption of oral medicines
4.6.3 Vestibular disorders
Hyoscine hydrobromide patch
nausea and vomiting associated with vestibular disorder and to reduce secretions in neurological conditions.
4.7.1 Non-opioid analgesics and compound analgesic preparations
Paracetamol and codeine should be prescribed separately and the dose titrated according to pain. Co-codamol may be prescribed in palliative care to reduce tablet burden.
Low dose weak opioid combinations with paracetamol (e.g. co-proxamol, co-codamol 8/500) offer little additional pain relief compared with regular full dose paracetamol and are not recommended.
Effervescent analgesics are not generally recommended because they are expensive and contain large amounts of sodium. Use is restricted to patients unable to swallow tablets or in the treatment of migraine attacks (see section 188.8.131.52).
4.7.2 Opioid analgesics
In general, the use of more than one opioid should be avoided.
Caution: Some opioids accumulate in renal impairment resulting in increased and prolonged effect.
Regular paracetamol (1g qds) may have an 'opioid-sparing' effect, thus enabling a lower opioid dose.
Efficacy does not increase above a certain dose; however, the risks of side effects and dependence do; do not prescribe more than 30mg of Dihydrocodeine as a single dose.
Patients with a definite intolerance to codeine.
4.7.3 Strong opioids
GHNHSFT Local Guideline: Policy for pain management in patients with morphine allergy
- oral, immediate release: Oramorph® liquid
- oral, modified release: Zomorph® capsules
- Oral, immediate release: Oxynorm® liquid, Shortec® capsules
- Oral, modified release: Longtec® tablets
- Bunov® (replaced weekly)
- Transtec® (replaced every 4 days)
Expensive: pain team / palliative care (useful in renal impairment)
Not suitable for acute pain or unstable/worsening pain
- oral: pain team / palliative care / substance misuse team
- patches (expensive): pain team / palliative care.
Not suitable for acute pain or unstable/worsening pain.
NOTE: in primary care, Fencino®, Mezolar® and Matrifen® are the lower cost fentanyl products of choice where a patch is definitely required.
- sublingual tablets (Abstral®): Pain team / palliative care. Breakthrough pain relief in patients with chronic cancer pain who are opioid tolerant and for whom immediate release morphine or oxycodone preparations are unsuitable / ineffective
Restricted to palliative care where eGFR < 30
Pain team / palliative care.
- parenteral: pain team / palliative care
- oral: substance misuse team
Pain team / palliative care / obstetrics (unsuitable for chronic pain due to short duration of action). The toxic metabolite nor-pethidine accumulates with repeated use and in renal impairment.
Pain team / palliative care. 3rd line use in patients for whom Zomorph® and Longtec® are ineffective or intolerable. Prescribing may only be transferred from Secondary Care to Primary Care following prior approval, in accordance with the Criteria Based Access Policy
4.7.4 Neuropathic pain
GHNHSFT Local Guideline: Neuropathic Pain
See section 4.8.1
(Axsain® cream) – diabetic peripheral neuropathic pain
Diabetic peripheral neuropathic pain (second line to amitriptyline)
Pain team / palliative care only
Palliative care only
Capsaicin 179mg [8%]
(Qutenza®) patches – Hospital only: Peripheral neuropathic pain in non-diabetic patients where recommended oral treatments are ineffective or not tolerated. Maximum of 2 patches per patient per treatment session.
4.7.5 Antimigraine drugs
184.108.40.206 Treatment of the acute migraine attack
- Simple analgesia (e.g. paracetamol, NSAIDs) is often effective.
- Dispersible or effervescent preparations are preferred because peristalsis is often reduced during migraine attacks.
- Formulations such as suppositories may allow absorption
- Concomitant anti-emetics may be required e.g. metoclopramide or domperidone tablets/suppositories (see 4.6)
- 5HT1 agonists if simple analgesia fails:
- If one 5HT1 agonist is ineffective patients may respond to another.
- 5HT1 agonists should not be used for prophylaxis and they are contraindicated in ischaemic heart disease, previous MI, coronary vasospasm (including Prinzmetal’s angina), and uncontrolled hypertension.
- Use of 5HT1 agonists with ergotamine/ergotamine-derivatives should be avoided.
Specialist use only
Injection: Specialist use only
220.127.116.11 Prophylaxis of migraine
Acute treatments are still required. Prophylaxis only reduces the severity and frequency of attacks. Please note however that 5HT1 agonists must not be taken within 24hrs of methysergide.
Consultant Neurologist initiation only
Botulinum A toxin
Botox® for chronic migraine as per NICE TA260
As per NICE TA682
Consultant Neurologist only. To be used when all other licensed oral options have failed or are unsuitable
As per NICE TA631
As per NICE TA659
18.104.22.168 Cluster headache: Acute
22.214.171.124 Cluster headache: Prophylaxis
4.8 Antiepileptic drugs
4.8.1 Control of the epilepsies
The choice of antiepileptic agent will depend on the type of epilepsy
Prescribing of Antiepileptic Drugs (AEDs):
Prescribers should consider the MHRA guidance (summarised below) regarding the generic prescribing of AEDs.
Category 1 – Phenytoin, carbamazepine, phenobarbital, primidone
For these drugs, prescribers are advised to ensure that their patient is maintained on a specific manufacturer’s product (i.e. prescribe by brand or by using the generic drug name and name of the manufacturer / marketing authorisation holder).
Category 2 – Valproate, lamotrigine, perampanel, rufinamide, clobazam, clonazepam, oxcarbazepine, eslicarbazepine, zonisamide, topiramate
For these drugs the need for continued supply of a particular manufacturer’s product should be based on clinical judgement and consultation with patient and/or carer taking into account factors such as seizure frequency and treatment history.
Category 3 - Levetiracetam, lacosamide, tiagabine, gabapentin, pregabalin, ethosuximide, vigabatrin
For these drugs it is usually unnecessary to ensure that patients are maintained on a specific manufacturer’s product unless there are specific concerns such as patient anxiety, and risk of confusion or dosing errors.
126.96.36.199 Sodium valproate (oral)
liquid – patients who are unable to swallow tablets and where Episenta® is not appropriate.
Please note that the use of valproate in females of childbearing age must be carefully considered due to the high risk of foetal abnormalities, and the Pregnancy Prevention Programme guidance followed.
188.8.131.52 Sodium valporate (parenteral)
Agents marked with an * are indicated when symptoms have not been controlled with other antiepileptics. They may only be prescribed on the recommendation of a Specialist.
See information above
Shared Care Guideline (intranet)
initiated & supervised by a Specialist
4.8.2 Drugs used in status epilepticus
buccal, out-patient use (in conjunction with an individual patient plan)
slow i.v. injection
injection – Use with caution: NPSA Rapid Response Report
(Pabrinex® IV/IM) – alcohol abuse
4.8.3 Febrile convulsions
Rectal tubes – prolonged or recurrent seizures
4.9 Drugs used in parkinsonism and related disorders
The symptoms of drug-induced parkinsonism, e.g. with antipsychotic drugs, may be suppressed with the antimuscarinic drugs. However, routine administration is not justified.
4.9.1 Dopaminergic drugs used in Parkinson's disease
184.108.40.206 Dopamine-receptor agonists
Where once daily dosing will improve compliance significantly.
For product continuity, consider prescribing as Pipexus®
Ropinirole MR (Ipinnia® XL)
Where once daily dosing will improve compliance significantly
Patch – restricted to patients who are unable to swallow (see local guideline)
Severe Parkinson's disease inadequately controlled by other preparations - see local guideline
Co-careldopa with entacapone
Intestinal gel (levodopa 20 mg/ml + carbidopa 5 mg/ml)
220.127.116.11 Monoamine-oxidase-B inhibitors
5mg, 10mg tablets
18.104.22.168 Catechol-O-methyltransferase inhibitors
Second-line where entacapone is not tolerated or where there has been a suboptimal response to entacapone
4.9.2 Antimuscarinic drugs used in parkinsonism
Antimuscarinics can be of help with tremor, but use is limited by side effects of confusion, prostatism, dry eyes, and dry mouth especially in the elderly.
4.9.3 Drugs used in essential tremor, chorea, tics, and related disorders
22.214.171.124 Torsion dystonias and other involuntary movements
Botulinum A toxin
Xeomin® for chronic sialorrhoea, as per NICE TA605
4.10 Drugs used in substance dependence
4.10.1 Alcohol dependence
In alcohol withdrawal Pabrinex® and/or thiamine may be required.
Facilities for treating anaphylaxis should be available when administering Pabrinex®.
4.10.2 Cigarette smoking
Contact Gloucestershire Smoking Advice Service (GSAS) for advice or referrals (0300 422 0040)
Nicotine replacement therapy
4.10.3 Opioid dependence
(buprenorphine/naloxone) – specialist advice only
Specialist advice only. Shared Care Guideline (intranet)
4.11 Drugs for dementia
- Patches (NB patches are an expensive option, and should only be used when oral dosage forms are not suitable; if patches are necessary, prescribe as Alzest®)
4.11.1 Anxiolytics and tranquillising drugs in elderly patients and patients with dementia
- Anxiety should be tolerated to some extent and, wherever possible, be managed by non-pharmaceutical means
- Medication is associated with a high frequency of unwanted and sometimes serious side effects.
- There is a clear increased risk of stroke and a small increased risk of death when antipsychotics (typical or atypical) are used in elderly people with dementia (Read more for MHRA advice)
- Depression and additional pathologies should be specifically sought.
- Sedation, parkinsonism and non-specific decline should be watched for.
- Benzodiazepine use in elderly patients is associated with falls and cognitive impairment.
Risk of stroke (see above)
Short-term use only