clozapine Flashcards
when is clozapine indicated
Schizophrenia in patients unresponsive to, or intolerant of, conventional antipsychotic drugs
important safety info with clozapine - reminder of potentially fatal risk of intestinal obstruction, faecal impaction, and paralytic ileus
Clozapine has been associated with varying degrees of impairment of intestinal peristalsis.
Patients and their carers should be advised to seek immediate medical advice before taking the next dose of clozapine if constipation develops.
a patient has got constipation and they are taking clozapine. is this ok?
Clozapine has been associated with varying degrees of impairment of intestinal peristalsis
Seek immediate medical advice before taking the next dose of clozapine if constipation develops
MHRA - Clozapine and other antipsychotics: monitoring blood concentrations for toxicity
following fatal cases involving toxicity of clozapine + other antipsychotics, MHRA recommends monitoring blood conc clozapine for toxicity in certain clinical situations e.g.
- pt stops smoking or switches to e-cigarette
- concomitant meds may interact to increase [clozapine]
- pnuemonia or other serious infection
- reduced clopazine metabolism suspected
- toxicity suspected
a patient who is on clozapine and aripiprazole has recently quit smoking. what does this mean
Following fatal cases involving toxicity of clozapine and other antipsychotic medicines, the MHRA recommends monitoring blood concentration of clozapine for toxicity in certain clinical situations e.g. when a pt stops smoking or switches to e-cig
monitoring for clozapine
- prolactin at astart, at 6 months, yearly
- leucocytes and differential blood counts - DBC weekly for 18 weeks, then fornightly for up to 1 year, then monthly as part of clozapine pt monitoring service
- only monotor [clozapine] in certain clincal situations
- close medical supervision during initiated - risk of collapse because of hypotension and convulsions
- blood lipids and weight base line, 3 months (frequent intervals during first 3 months), every 3 months for first year, yearly
- FBG baseline, one month, then 4-6 months
a patient is on clozapine. what does this mean for you
Patient, prescriber, and supplying pharmacist must be registered with the appropriate Patient Monitoring Service—it takes several days to do this.
clozapine planned withdrawal
reduce dose over 1–2 weeks to avoid risk of rebound psychosis. If abrupt withdrawal necessary observe patient carefully.
for clozapine, in addition to normal monitoring requirements for all antipsychotics, you also need to monitor leucuocyte and differential blood counts. how often?
differential white blood cell monitoring weekly for 18 weeks, then fortnightly for up to one year, and then monthly as part of the clozapine patient monitoring service.
hypersalivation with clozapine therapy can be treated with this drug (unlicensed indication) provided that the patient is not at particular risk from the additive antimuscarinic side-effects of this drug and clozapine.
hyoscine hydrobromide
what blood disorders can clozapine cause, hence the monitoring requirements for luecocytes and differential blood counts
Neutropenia and potentially fatal agranulocytosis reported
Myocarditis and cardiomyopathy with clozapine
Fatal myocarditis (most commonly in first 2 months) and cardiomyopathy reported
discontinue permanently if this occurs induced by clozapine
clozapine should be used with caution in pt recieving drugs that may cause constipation e.g. antimuscarinics or in hisotry of colonic disease of lower abdominal surgery because…
Impairment of intestinal peristalsis, including constipation, intestinal obstruction, faecal impaction, and paralytic ileus, (including fatal cases) reported.
drugs that can cause constipation need to be used with caution as concurrent use might increase risk of developing intestinal obstruction
antimuscarinics - chlorphenamine, amitriptyline, darifenacin, solifenacin, tolterodine
opioids
antipsychotics
iron
can you use in severe cardiac disorders
e.g. myocarditis
no
