Canterbury DHB

Context

Polypharmacy Toxicities

In This Section

Serotonin Toxicity

Anticholinergic Toxicity

QT Interval Prolongation

Serotonin Toxicity

Common serotonergic drugs

Class

Drugs

SSRIs

citalopram, escitalopram, fluoxetine, paroxetine, sertraline

Serotonin and Noradrenaline Reuptake Inhibitor (SNRIs)

venlafaxine

Monoamine Oxidase Inhibitors (MAOIs)

moclobemide, tranylcypromine, phenelzine

tricyclic antidepressants (TCAs)

amitriptyline, clomipramine, nortriptyline

Noradrenergic and Specific Serotonergic Antidepressant (NaSSa)

mirtazapine

analgesics

pethidine, tramadol

triptans

sumatriptan

other

buspirone, carbamazepine, lithium, valproate sodium

herbal medicines

St John’s wort

Anticholinergic Toxicity

Drugs with strong, moderate, or weak anticholinergic potency

 

Strong

Moderate

Weak

Antidepressants:

amitriptyline, clomipramine, paroxetine

nortriptyline and all other ‘non-strong’ tricyclic antidepressants

mirtazapine, venlafaxine

Antihistamines:

promethazine

 

cetirizine, loratadine, ranitidine

Antipsychotics:

chlorpromazine, clozapine

olanzapine, quetiapine

aripiprazole, haloperidol, lithium, risperidone

Anticholinergics:

benzatropine, oxybutynin, solifenacin, tolterodine (may be selective for bladder acetylcholine receptors)

hyoscine, procyclidine

 

Antiparkinsonian:

 

amantadine

carbidopa-levodopa, entacapone, pramipexole, ropinirole, selegiline

Antiemetic:

prochlorperazine

 

metoclopramide

Others:

 

baclofen, carbamazepine, loperamide (usually local effect on the gut only)

codeine, digoxin, tramadol, warfarin

NB *Inhaled e.g. tiotropium, ipratropium, glycopyrronium, umeclidinium or topical anticholinergic drugs have low systemic exposure but may have systemic effects at high doses or in susceptible patients.

QT Interval Prolongation

QTc prolonging drugs

Class

Drugs

antiarrhythmics

amiodarone

flecainide

sotalol

 

CNS drugs

antipsychotics

SSRIs

tricyclic antidepressants

lithium

macrolide antimicrobials

azithromycin

clarithromycin

erythromycin

roxithromycin

other

cisapride

chloroquine

domperidone

methadone

Predisposing Factors

Monitoring

ECG measurement of the QTc interval prior to and early on in treatment (when at, or approaching, steady-state) is recommended for all patients:

Information about this Canterbury DHB document (93252):

Document Owner:

Not assigned (see Who's Who)

Last Updated:

November 2016 (Polypharmacy Toxicities)

Next Review Due:

November 2018

Keywords:

Note: Only the electronic version is controlled. Once printed, this is no longer a controlled document.

Topic Code: 93252