CNS stimulants Flashcards
What is 1st line drug treamtnet for ADHD - 2 options
lisdexamfetamine methylphenidate
methylphenidate - if effect wears off in evening with rebound hypersensitivity, the following may be appropriate
dose at bed time may be appropriate - establish need with trial bedtime dose
generic methylphenidate is used for ADHD, and also for this indication (unlicensed) (using IR meds)
narcolepsy
MHRA safety info re methylphenidate PR preps - caution if switching between products due to differences in formulation
All LA preps contain an IM component and a MR component
biphasic release profiles of diff preparations are NOT all equivalent and contain different proportions of IR and MR components
A patient has arrhythmias - are they suitable for treatment with methylphenidate
No it is contraindicated in arrhythmias
Methylphenidate causes growth retardation in children -T or F
true
Monitoring for methylphenidate
- psychiatric disorders
- pulse, BP, psychiatric symptoms, appetite, weight and height - initiation, dose adjustment, at least every 6 months thereafter
Why should alcohol be avoided with methylphenidate
it might increase conc of methylphenidate
TCAs interaction with methylphenidate
methylphenidate may increase conc of TCAs e.g. amitriptyline, imipramine, doxepin, dosulepin etc
use with caution and adjust dose
interaction - MAOB inhibitor and methylphenidate
selegiline, rasagiline
these are predicted to increase risk of hypertensive crisis when given with methylphenidate - avoid
interaction between methylphenidate and MAOIs
Methylphenidate causes a hypertensive crisis when given with Tranylcypromine, isocarboxazid, phenelzine Manufacturer advises avoid and for 14 days after stopping the MAOI.
avoid this high risk abx because methylphenidate may increase risk of elevates BP when given with it
linezolid
dexamfetamine can be used (unlicensed) for refractory ADHD, initiated under specialist supervision. If the following syndrome occurs, discontinue
tics
Monitor these two parameters as growth restriction can occur during prolonged therapy with dexamfetamine
height and weight
What can you do to reduce risk of growth restriction with prolonged therapy with dexamfetamine
Drug free periods may allow catch up in growth by withdraw slowly to avoid inducing depression or renewed hyperactivity
Which drug for ADHD has interactions with serotinergic drugs leading to risk of serotonin syndrome?
Dexamfetamine & lisdexamfetamine
Dexamfetamine interaction with MAOIs (2)
Predicted to increase the risk of a hypertensive crisis when given with MAOIs. Manufacturer advises avoid and for 14 days after stopping the MAOI. Also increased risk of serotonin syndrome
Dexamfetamine interactions with MAO-B inhibitors. (2)
Rasagiline, selegiline is predicted to increase the risk of severe hypertension when given with Dexamfetamine. Manufacturer advises avoid. Also increased risk of serotonin syndrome
Dexamfetamine and -perazine antipsychotics interaction
They are predicted to decrease the effects of dexamfetamine and dexamfetamine is predicted to decrease their effects
Dexamfetamine and SSRIs, SNRIs (dulox, venlfax), bupropion, TCAs, ondansetron, lithium, methadone, triptams, pethidine, vortioxetine etc
can increase the risk of serotonin syndrome
Amfetamines in overdose - what are the symptoms (initial and after)
wakefulness
excessive activity
paranoia
hallucinations
hypertension
followed by exhaustion, convulsions, hyperthermia and coma
A patient presents to A&E. You are told that initially, they were very hyperactive and had hallucinations. They now seem to be very exhausted, dizzy and hyperthermic. You look at their medication list: sertraline 50mg OD, dexamfetamine 10mg OD, salamol 2 puffs up to QDS prn. What do you suspect?
Amfetamine overdose - cause akefulness, excessive activity, paranoia, hallucinations, and hypertension followed by exhaustion, convulsions, hyperthermia, and coma.
Treatment of early Staes of amfetamine overdosage
diazepam or lorazepam
dexamfetamine monitoring requirements
- monitor growth in chilsren
- monitor for aggressive behaviour or hostility during initial treatment
- pulse, BP, psychiatric symptoms, appetite, weight and height at initiation, each dose adjustment, and at least every 6 months thereafter
Do ADHD drugs cause weight GAIN or weight LOSS
weight loss
Lisdexamfetamine relationship with dexamfetamine
Lisdexamfetamine is a prodrug of dexamfetamine.
Lisdexamfetamine is contraindicated in hypo or hyperthyroidism
HYPER
Discontinue amphetamines if the following occurs
seizures
All amphetamines to be used with caution in …
psychiatric disorders e.g. Bipolar disorder
Bupropion MHRA advice with all amphetamines
B might increase risk of serotonin syndrome when given with amphetamines - monitor
Moclobemide interaction with lis/dexamfetamine
predicted to increase the risk of a hypertensive crisis when given with Moclobemide. Manufacturer advises avoid.
also increased risk of serotonin syndrome
RI - max dose of lisdexamfetmine in severe impairment
max dose 50mg daily
Should amphetamines be stopped
avoid abrupt withdrawal
Depression, drowsiness, fever, psychiatric disorders and skin reactions are very common in children taking lisdexamfetamine - true or false
true
Lisdexamfetamine warning labels
This medicine may make you sleepy. If this happens, do not drive or use tools or machines.
Swallow this medicine whole. Do not chew or crush.
A patient has moderate hypertension. Can you give lisdexamfetamine
No - contraindicated
Monitoring - lisdexamfetamine
- aggressive behaviour or hostility during initial treatment
- pulse, BP, psychiatric symptoms before initiation, following dose adjustment, every 6 months thereafter
- monitor weight in adults before treatment initiation and during treatment
- children: height and weight before initiation, and then height, weight and appetite at least every 6 months during
