pimozide and haloperidol

Question 1

important interactions are to do with the following 2 factors (pimozide)

Answer 1

qt prolong
hypokalaemia

Question 2

decreased or increased appetite as a side effect? (pimozide)

Answer 2

decreased

Question 3

important monitoring (pimozide)

Answer 3

Following reports of sudden unexplained death, an ECG is recommended before treatment.

Question 4

can you give with other antipsychotics (pimozide)

Answer 4

pimozide should not be given with other antipsychotic drugs (including depot preparations)

due to its risk of qt prolongation

Question 5

true or false - pt should have annual ecg (pimozide)

Answer 5

true
recommended that patients taking pimozide should have an annual ECG (if the QT interval is prolonged, treatment should be reviewed and either withdrawn or dose reduced under close supervision)

Question 6

what to do if ecg shows that qt interval is prolonged (pimozide)

Answer 6

review treatment
either withdraw or reduce dose under close supervision

Question 7

avoid giving these with pimozide

Answer 7

other anti psychotics, tricyclic antidepressants or other drugs which prolong the QT interval, such as certain antimalarials, antiarrhythmic drugs and certain antihistamines and should not be given with drugs which cause electrolyte disturbances (especially diuretics)

Question 8

what is the MHRA advice for haloperidol

Answer 8

reminder of risks when used in elderly patients for the acute treatment of delirium

elderly patients are at an increased risk of adverse neurological and cardiac effects, and special caution is required when using haloperidol for the acute treatment of delirium in frail, elderly patients.

only consider when non-pharmacological interventions are ineffective and no contra-indications are present (e.g. Parkinson’s disease and dementia with Lewy bodies).

Before initiating treatment, a baseline ECG and correction of any electrolyte disturbances is recommended; cardiac and electrolyte monitoring should be repeated during treatment. Monitor patients for any extrapyramidal adverse effects e.g. acute dystonia, parkinsonism, tardive dyskinesia, akathisia, hypersalivation, and dysphagia.

The lowest possible dose for the shortest possible time should be used, and any dose increase should be gradual and reviewed frequently.

Question 9

monitoring for haloperidol

Answer 9

Manufacturer advises monitor electrolytes before treatment initiation and periodically during treatment.

A baseline ECG is recommended before treatment initiation and the need for further ECGs during treatment must be assessed on an individual basis

Question 10

does smoking affect haloperidol

Answer 10

yes may need dose adjustments of smoking started or stopped during treatment

Question 11

interactions with haloperidol are to do with

Answer 11

hypotension
hyponatraemia
CNS sedation
hypokalaemia
QT prolong