Antipsychotic medicine prescribing & monitoring Flashcards
What is the structure of Adult Mental Health (19:13) services in Nottingham?
- Primary care (GP, mental health nurses)
- Specialist MH Services
- Early Intervention in Psychosis (EIP) Teams
- Crisis and Home Treatment Teams (CRHT)
- Community MH Teams
- Assertive Outreach Teams (patients not engaging w/primary care teams)
- Section 136 Suites (vulnerable patients in a place of safety, under the Mental Health Act)
- In-Patient care; acute (formal/informal), residential rehab
What does a MH MDT look like?
- GP
- Psychiatrist
- Junior doctors
- Psychiatric nurses
- Pharmacists
- Healthcare assistants
- OTs
- Psychologists
- Non-medical prescribers
- Social workers
What is the role of the pharmacist in a MH MDT?
- Explain medicines
- Provide information
- Support adherence
- Monitor S/Es; using GASS (Glasgow Anti Psychotic Scale) and LUSNERS
- Physical health
- Identify polypharmacy/high-doses
- Review treatment plans
- Drug histories
- Identify drug-interactions
- TDM result interpretation (e.g. Clozapine)
- Signposting to services
- MHA (Mental Health Act) Second Opinion Consultee; can give medications for 3 months w/o formal consent under Mental Health Act
- Promote evidence-based treatments
- Simplify regimens
- Review PRN use
- Break the stigma
- Support prescribers
- Links to MH services
- Support carers
- Health promotion
- Healthy choices
- Smoking cessation
- Smoking/CYP450-1A2 induction/Clozapine; heavy smokers metabolise smokers much faster as a result
What is the target receptor to treat psychosis? Give examples.
D2 blockade (positive symptoms): - Haloperidol - Risperidone - Amisulpride (marked blockade)
What does blocking 5-HT2 do w/antipsychotic therapy? Give examples.
Provides protection against extrapyramidal S/Es: (Atypicals) - Risperidone - Olanzapine - Quetiapine - Clozapine (marked blockage; protection)
What occurs if antipsychotics have M, H1 or Alpha-1 receptors activity?
- M; muscarinic side effects (clozapine, olanzapine)
- H1; histamine, causes sedation/drowsiness (clozapine, olanzapine, quetiapine)
- Alpha 1; postural hypotension, dizziness etc. (dose-related; start low, go slow)
What is the PANSS rating scale?
- Positive And Negative Symptom Scale
- For patients to report their symptoms (whilst on antipsychotic treatment)
What is the short-term efficacy of antipsychotics like?
Relieves acute (positive) symptoms:
- Quickly calm, reduces anxiety, helps sleep
- Delusions, hallucinations, thought disorder improve over weeks
Limited effect on chronic (negative) symptoms:
- Social withdrawal, flattening of mood, poverty of speech, lack of drive/motivation/initiative
What are the guidelines to ensure long-term efficacy of antipsychotics?
- 60-70% w/schizophrenia relapse within one year of stopping medication
- Only 10-30% relapse if they continue treatment as prescribed
- Continue medication for at least 1-2 years (following recovery from acute episode)
- Do not stop medication abruptly (brain adapts; titrate down over at least 1 month)
- Monitor for signs/symptoms of relapse for 2 years after stopping medication
What different formulations are availible for antipsychotic treatment?
- Olanzapine, aripiprazole and risperidone availible as orodispersible tablets
- Freeze-dried wafer; disperses in saliva, difficult to conceal (but do not act faster than normal tabs)
- Short-acting injections; rapid tranquillisation
- Long-acting ‘depot’ injections (IM in gluteal/deltoid); improve adherence
What is rapid tranquilisation and what is its aim?
- Use of medicine to quickly control extreme agitation, aggression and potentially violent behaviour that put the individual/those around them at risk of physical harm
- Aim to sedate the person to minimise risk, without the person losing consciousness.
• Time out
• Distraction
• Seclusion
• Restraint
What medicines are availible for RT?
- Lorazepam (first line; BZD)
- Haloperidol + Promethazine (NICE recommended; Phenergan, sedative antihistamine)
- Etc.
> > > Flumazenil is BDZ antagonist (GABA antagonist) to treat excessive drowsiness/respiratory depression
Which RT is no longer recommended any why?
Clopixol-Acuphase (Zuclopenthixol; antipsychotic)
- Slowest acting
- Takes 24 hours to reach peak plasma conc.
What are the risks of drugs used in RT? Which drugs have a better tolerated S/E profile?
Both APs and BZDs share risk of:
- Excessive sedation
- Loss of consciousness
- Respiratory depression/arrest
- Cardiovascular complications/collapse
BUT, APs also have risk of:
• Seizures
• Akathisia (agitation/restlessness stage)
• Dystonia (involuntary muscle contractions)
• Dyskinesia (abnormal/impaired voluntary movement)
• NMS (neuroleptic malignant syndrome)
Whereas BZDs just additionally have:
• Risk of non-access to flumazenil (BZD antagonist in OD)
How are the risks monitored in RT?
Monitor:
- Levels of consciousness
- Respiration
- Blood pressure
- Pulse
- Temperature
What are the considerations when using long-acting antipsychotics (depots etc.)?
- Half-life
- Gluteal vs. deltoid for location of injection
- Fridge storage
- Loading dose considerations (PO?)
- Onset of action (PO in meantime)
- Time to SS
Which LA depot antipsychotics last for longer, and why?
Typicals:
- Paliperidone palmitate (Xepilon)
- Decanotate, palmitate (OIL- BASED)
> Last for 3 months
Atypicals: - Risperidone Consta - Aripiprazole Maintena - Olanzapine ZypAdhera > Given every 2 weeks/monthly; newer atypicals are aqueous based
What is the potential danger of using Olanzapine ZypAdhere LA AP?
Post-injection syndrome:
- Drug enters vein instead of muscle
- Resulting olanzapine overdose in blood
What is Treatment-Resistant Schizophrenia? What therapy is then used?
- Failure to respond to two different antipsychotics (one of which is an atypical), each trialled for at least 6-8 weeks in recommended doses
- Clozapine then becomes drug of choice; introduced at earliest opportunity
What are some potential reasons for Treatment-Resistant Schizophrenia?
- Not taking the medicines
- Alcohol/illicit drug use
What are the conditions for clozapine use/what tests are involved? How is it metabolised?
- Full blood count (FBC)
- No blood test = no clozapine:
• Weekly bloods for first 18 weeks
• Fortnightly bloods to 1 year
• Then monthly bloods thereafter - RED alert result; stop clozapine immediately (dip in neutrophil/WBC count; agranulocytosis risk)
- CI w/other drugs that can cause bone marrow suppression
»> Metabolised by: C1A2 & C2D6
What is the risk of neutropenia/agranulocytosis in clozapine use, and when is this likely to occur?
- Neutropenia; 3% risk
- Agranulocytosis; 0.5% risk (blood dyscrasia etc.)
»> Usually within first 18 weeks
What are the common dose-related S/Es of clozapine and how are they managed?
Dose-related S/Es include:
- Drowsiness
- Hypertension/hypotension, and dizziness
- Increased heart rate (> 100 bpm)
- Raised body temperature
- Hypersalivation
- Nocturnal enuresis (urination during sleep)
- Raised blood glucose
- Raised blood lipid levels (dyslipidemia)
How to minimise:
Gradual dose-titration essential to minimise dose-related S/E’s:
• 12.5mg nocte on Day 1
• 25mg nocte on Day 2
• 25mg mane + 25 mg nocte Day 3
• Increase by 25-50mg/day every 2-3 days to usual range: 150-400 mg/day
• Max 900mg/day in divided doses
What other S/Es of clozapine may present, and how are these ones by actively managed?
Constipation
- Usually persists, can be severe (TREAT)
Weight gain (atypicals) - Dietary, exercise advice
Nausea
- May need antiemetic e.g. domperidone
Lowers seizure threshold:
- Mainly problematic at doses > 600 mg/day
- Use prophylactic sodium valproate above 600mg/day
Cardiomyopathy/myocarditis
- Signs: persistent tachycardia w/fever, hypotension or chest pain
- Rare but MAYBE FATAL
What options are there if 3rd-line treatment w/clozapine is ineffective?
- Assess response over at least 6 months
- Gradually increase dose
- Monitor plasma concentrations of clozapine (trough level 350-500mcg/L)
- Augment w/second antipsychotic for a trial period (e.g. sulpiride, amisulpride)
»> 1/3 respond well, 1/3 respond moderately, 1/3 are not effective
If a patient misses more than 48 hours of clozapine treatment, do they still move up to the next titrated dose?
No; patient will have lost tolerance, thus must be re-titrated.
According to NICE guidelines, who must be the one to start antipsychotic therapy on a first presentation?
GPs should not start antipsychotics on a first presentation in primary care; unless done in consultation with a consultant psychiatrist.
How is the decision of which antipsychotic to use made?
- Decision to be made by patient and HCP together, in conjunction w/the carer if the patient agrees
- Provide information and discuss likely benefits and possible S/Es of each drug, including:
• Metabolic
• Extrapyramidal
• Hormonal
• Other (unpleasant subjective experiences etc.)
What information is out there for patients to make an informed decision regarding their antipsychotic therapy?
- Informed discussion between HCP and patient
- Decision aids; e.g. Choice and Medication website, NHS Choices
What baseline investigations should be conducted prior to a patient starting antipsychotic therapy?
- Physical examination
- Weight, BMI, waist circum.
- Pulse and BP
- Fasting blood glucose, HbA1c
- Fasting blood lipids
- Prolactin levels
- ECG if specified in the SPC, or if CV risk factors
- Movement disorders
- Nutritional status, diet and level of physical activity
- Smoking status
- Alcohol intake
What routine monitoring should be undertaken for a patient on long-term antipsychotic therapy?
- Response (changes in symptoms, behaviour)
- S/Es (inc. EPSE; extrapyramidal side effects), and impact on functioning
- Weight, weekly for the first 6/52, then at 3/12, then annually
- Fasting blood glucose, HbA1c and lipids at 3/12 then annually
- Adherence checks
- Overall physical health
- ‘Shared-care’ w/GP
What is ‘good prescribing’ WRT to antipsychotics, as defined by NICE?
- Record indication, benefits/risks, expected response time
- Start at lower end of dose range, slowly titrate upwards keeping within BNF limits
- Consider therapeutic trial as 4-6 weeks at optimum dose
- Justify and record reasons for Rx doses above BNF limits
- Record rationale for continuing/changing/stopping medication, and the effect of such changes
- Avoid polypharmacy, except for short periods (e.g. when switching antipsychotics)
»> “Start low, go slow”
What are the general pointers re. antipsychotic prescribing and monitoring?
- Support patient choice
- Ensure understanding
- Use lowest effective dose (within BNF limits)
- Start low and go slow
- Prescribe one AP at a time (exceptions)
- Review effect on target symptoms
- Monitor and manage SEs
- Support adherence
- Don’t forget physical health
