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Clozapine. Clozapine An atypical antipsychotic used in: Treatment resistant schizophrenia (TRS) Patients intolerant of other antipsychotics Drug induced psychotic disorders occurring during the treatment of Parkinson's disease. Some ‘off-license’ indications e.g. delusional disorder.
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Clozapine An atypical antipsychotic used in: • Treatment resistant schizophrenia (TRS) • Patients intolerant of other antipsychotics • Drug induced psychotic disorders occurring during the treatment of Parkinson's disease. • Some ‘off-license’ indications e.g. delusional disorder
Clozapine Patient Monitoring Service (CPMS) CPMS require that all: • Pharmacists/technicians and pharmacy premises supplying clozapine are registered with them. • Consultants prescribing clozapine are registered with them. • All patients receiving clozapine treatment are registered and monitored by them.
Clozapine Initiation I Prior to starting Clozapine baseline monitoring should be done: • Full Blood Count • ECG • EEG (advised in adolescents) • Weight • Fasting lipids/glucose • Baseline assessment of mental state • Lying + standing blood pressure, temperature and pulse
Clozapine Initiation II Speak with patient starting clozapine about: • Commitment to regular blood monitoring required • Provide a CPMS handbook to the patient. This gives information about side effects and benefits as well as everything the patient needs to know about Clozapine. (Handbooks are available from CPMS). • Discuss possible side-effects with patient. Patient friendly information is available from Sussex Partnership intranet.
Possible Side-Effects • Patients should be made aware that FBC monitoring is a prerequisite of ongoing clozapine supply. • They should also be made aware that there are possible potentially serious side effects: • 3% Risk of developing neutropenia • Cardiac effects (myocarditis) • Constipation and chronic bowel obstruction • Weight gain • Hypersalivation • Tachycardia • Seizures (higher doses & dose related) • Doses will be titrated up slowly due to effects on BP and HR and to prevent severe side effects.
Once it has been decided to start clozapine the patient will need to be registered with CPMS. Forms available on CPMS website. To be completed by a CPMS registered consultant.
Blood Monitoring • A second FBC should be done after 4 days and treatment started within 10 days of the first test. • Following registration: • A weekly FBC must be done for the first 18 weeks. • A fortnightly FBC must be done for the rest of the first year. • A monthly FBC must be done thereafter.
Supply of Clozapine • The CPMS registered Pharmacy will make a supply depending on the patients monitoring status. • Weekly 7 days supply (absolute maximum 10 days) • Fortnightly 14 days supply (absolute maximum 21 days) • Monthly 28 days supply (absolute maximum 42 days supply)
Blood kits and barcodes Orange envelope for FBC Yellow envelope for plasma level The blood kits are the same for both tests Each patient has their own barcodes which need to be attached to the paperwork and the blood vial. All non drug items, (bloodkits, envelopes, paperwork and barcodes) are to be ordered by the ward / unit using the non drug order form (available on the CPMS website)
Titration • Clozapine is gradually titrated over the first 14 days and the patient is monitored carefully during the titration. • This is to lessen any side effects and to ensure that the patient can tolerate clozapine. • Temperature, pulse and B.P is monitored and a record is made of any of the common side effects suffered by the patient.
Monitoring • For both inpatients and outpatients a full examination should be undertaken each week during titration • Nurses should inform the doctor if: • Temperature rises above 38° C (this is common and on its own not a good reason to stop clozapine) • Pulse is >100 BPM • Postural drop of >30mmHg • Patient clearly over sedated • Any other adverse effect is intolerable
Compliance Issues I • If a dose is omitted, take next dose at normal time • If patient has missed >48 hours, complete re-titration is necessary because tolerance to hypotensive effects diminishes rapidly: • Inform doctor and pharmacist immediately • Recommended to restart at 12.5mg on first day as before • However, sometimes possible to do “fast titration” • Ensure observations are done as before
Compliance Issues II • If < 96 hours have been missed the blood monitoring frequency stays the same. • If > 96 hours has been missed the patients blood monitoring becomes weekly again for 6 weeks before returning to the original frequency.
Smoking Cessation • The hydrocarbons in tobacco smoke induce the production or activity of various liver enzymes, in particular cytochrome CYP1A2, an enzyme associated with the metabolism of several drugs, including clozapine. This results in reduced plasma levels of such drugs. • When a patient stops smoking the metabolism of these drugs will decrease and plasma levels will rise. For clozapine plasma levels may be elevated by up to 70%, leading to toxicity. • CYP1A2 activity is affected by hydrocarbons in cigarettes and not by nicotine. Therefore nicotine replacement therapy (NRT) will not affect drug metabolism. • Patients, carers and healthcare professionals should be advised to inform the responsible medic if the patients starts or stops smoking.
Smoking Cessation • Patients should still be encouraged to stop or reduce smoking. • If a patient decides to stop smoking- • Latest clozapine levels should be reviewed and a new baseline level taken as soon as practicable (this is not urgent as dose reduction is not required immediately) • Reviewside-effects history and, if possible, check against the serum clozapine levels at which they occurred. • Assessthe risk of toxicity (ie. if level exceeds 1000ng/ml) by estimating the non-smoking serum clozapine level using the formula below: Serum clozapine (Non-smoker) = [1.5 x Serum clozapine (Smoker) ] + 50 eg. smoking level of 500ng/ml gives a non-smoking level of 800ng/ml
Smoking Cessation • Set a target (non-smoking) serum clozapine level, taking into consideration the patient’s current condition and clinical response to current dose / level. If indicated, adjust the clozapine dose accordingly. • Necessary reductions in daily dose should normally be made at a rate of approximately 10% per day. • If possible, monitorserum clozapine level at day 3 and then weekly (until stabilised to target level). • Monitor for adverse effects – bearing in mind that some may take as long as 2 to 3 weeks after adjustment of dose to become apparent. • On discharge or leave, reassess patient’s likelihood to recommence smoking and the potential reduction in serum clozapine level in response. If this occurs it is likely that the clozapine dose will have to be increased. • Post-discharge, where possible, monitor serum clozapine level once each week, (or fortnightly if total dose change was less than 20%), until stable.
On discharge from an inpatient setting • Check which registered Pharmacy will be supplying clozapine. This is dependent on where they live. • Make arrangements for the patient to be given access to blood monitoring supplies. These are ordered and supplied by the CPN • Arrange with the registered Pharmacy where the medication is to be collected from. • Make sure that the patient is transferred on CPMS to the outpatient consultant and that a current prescription has been sent to the pharmacy. All change of detail forms are available on CPMS website
SPT Community clozapine prescription • The doctor will need to supply an outpatient clozapine prescription. • This is: • Current for six dispensings • For clozapine supply only - all other meds should be prescribed by the GP • There are areas on the chart to record: • Allergy status • Delivery method • Blood test frequency • Dispensing frequency
If a clozapine patient is admitted or handed over to your team • Check when last blood was taken and when next blood is due - ask pharmacy • Check how frequently blood tests are needed - ask pharmacy • How much clozapine does the patient have? - ask the team or patient • Blood tests should be done on a Monday and posted to CPMS (Orange Envelope) • If you miss this a local test can be done but this will cost your team. £££! • Barcodes for blood tests can be handed over from the ward and further supplies re-ordered using the non drug order form.
Summary • Keep Pharmacy informed of any clozapine patients • Admissions • Registrations • Short leaves • Discharges • Dose changes • Area changes • Consultant changes • In short anything to do with Clozapine - Pharmacy want to know about it!
