ADHD Flashcards
What is ADHD?
A neurodevelopmental disorder characterized by difficulties with attention, hyperactivity, and impulsivity.
Treatment in children 5+
- Methyphenidate
- If not tolerated after 6 weeks = lisdexamfetamine
o This causes prolonged duration of sfx - If this is an issue for pt = dexamfetamine
Treatment in children 5+ if both methylphenidate and lisdexamfetamine CI
atomoxetine or guanfacine
Treatment in adults
- Methyphenidate or lisdexamfetamine
o Lisdexamfetamine causes prolonged duration of sfx
o If this is an issue for pt = dexamfetamine - Atomoxetine
Methyphenidate or lisdexamfetamine
o Lisdexamfetamine causes prolonged duration of sfx
o If this is an issue for pt = dexamfetamine
Methylphenidate - MOA
Potent CNS stimulant.
Increased dopamine and noradrenaline levels in the brain.
Methylphenidate is a CNS stimulant: Side effects
Causes sympathetic pathways to be excited
* High bp, Tachycardia, Arrythmias
* Behaviour and mood changes, Drowsiness and sleep disorder
* Decreased appetite, Growth retardation, Weight loss
Methylphenidate monitoring
Monitoring = following dose adjustments then 6 monthly
* Pulse
* Bp
* Psychiatric symptoms
* Appetite
* Weight
* Height at initiation
Methylphenidate - contraindications
CVD
Hyperthyroidism
Severe hypertension
Uncontrolled BPD
Severe depression
Methylphenidate - MHRA (2022)
Caution when switching between MR preparations.
Prescribe by brand.
MR preparations contian immediate release and modified release components. Different preparations contain different proportions of immediate-release and modified-release components = different release profiles.
MR preps preferred due to
- Pharmacokinetic profile
- Convenience – take less a day
- Improved adherence
Should be prescribed as brand only
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
Take in morning with breakfast for these two brands of methylphenidate
Medikinet, Equasym
A patient has arrhythmias - are they suitable for treatment with methylphenidate
No it is contraindicated in arrhythmias
If a patient has dysphagia, the following three brands of methylphenidate do not have appropriate dose form due to restricted GI lumen
concerta xl, demlosart PR tabs, xaggitin xl
Methylphenidate causes growth retardation in children -T or F
True
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
Lisdexamfetamine and dexamfetamine MOA
Potent CNS stimulant.
Increases dopamine and noradrenaline levels in the brain.
Lisdexamfetamine and dexamfetamine side effects
Similar SFx to methylphenidate
Lisdexamfetamine and dexamfetamine overdose
- Wakefulness, excessive acitivity, paranoia, hallucinations
- Hypertension
- Followed by: exhaustion, convulsion, hypothermia, coma
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
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
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.
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
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.
Atomoxetine MOA
Noradrenaline reuptake inhibitor
Causes increased levels of noradrenaline at the synaptic cleft
When should atomoxetine dose be taken?
morning
if given as divided dose, last dose should be no later than early evening
Atomoxetine - children max licensed dose
100mg daily
Atomoxetine - adults max licensed dose
dose max of 120mg not licensed
Atomoxetine - CI
phaeochromocytoma
severe CVD
severe cerebrovascular disease
Avoid this drug class, and for 2 weeks after stopping it, because it is predicted to increase the risk of adverse effects when given with atomoxetine
MAOIs - tranylcypromine, phenelzine, isocarboxazid
Atomoxetine side effects
o Causes QT prolongation
- Avoid concomitant drugs that prolong QT interval
o Hepatotoxicity
- counsel pt to report signs of toxicity e.g. N + V, malaise, dark urine, abdominal pain, jaundice
o Suicidal ideations
- counsel pt to report suicidal thoughts, self-harming behaviour, irritability, anxiety or depression.
Atomoxetine - monitoring
Monitor on initiation, every 6 months and after a dose change.
Pulse
BP
Appetite
Weight
Height
Atomoxetine - dose adjustments in HI
1/2 dose in moderate impairment
1/4 dose in severe
Atomoxetine is …toxic so patients and carers should be advised of the rare risk and be told how to recognise symptoms; prompt medical attention should be sought in the case of ….
Hepatotoxic
Jaundice, unexplained n/v, malaise, dark urine, abdominal pain
Atomoxetine - label
This medicine may make you sleepy. If this happens, do not drive or use tools or machines
Atomoxetine is associated with sexual dysfunction - T or F
True
Guanfacine - cautions
Bradycardia (risk TDP)
Heart block (risk TDP)
History CVD
History QT interval prolongation
Hypokalaemia (risk TDP)
Guanfacine - Signs of overdose
hypotension, initial hypertension, bradycardia, lethargy, and respiratory depression
patients who develop lethargy should be observed for development of more serious toxicity for up to 24 hours
Guanfacine - contraception
Contraception needed?
effective contraception in females of childbearing potential
True of false - you need to measure BMI after treatment for Guanfacine
false
take BMI before, then every 3 months for 1 year, then every 6 months
True or false - you need to monitor BP and pulse regularly in pt taking guanfacine
False - monitor these during dose downward titration and following discontinuation of treatment
True or false - unlike the amphetamines and atomoxetine, you can abruptly withdraw guanfacine
False - avoid abrupt withdrawal; consider dose tapering to minimise potential withdrawal effects.
Is there any special directions for administration for guanfacine?
Manufacturer advises avoid administration with high fat meals (may increase absorption).
Guanfacine labels
Warning: This medicine may make you sleepy. If this happens, do not drive or use tools or machines.
Do not drink alcohol.
Swallow this medicine whole. Do not chew or crush.
Do ADHD drugs cause weight GAIN or weight LOSS
weight loss
