clinical pharmacologyu Flashcards
what is the active metabolite of diazepam
Desmethyldiazepam
what is the active metabolite of dothiepin
Dothiepinsulfoxide
what is the active metabolite of fluxotine
norafloxetine
what is 9-Hydroxyrisperidone an active metabolite of?
Risperidone
what is desipramine an active metabolite of?
Imipramine
is Nortriptyline a metabolite or a drug? If so, what is the other one associated?
it is an active metabolite
its paired with Amitriptyline (drug)
Which is the active metabolite -codeine or morphine?
morphine is the active metabolite
codeine is the drug
list 5 medications used in ADHD
- Dexamfetamine / lisdexamfetamine (prodrug of Dex)
2.Methylphenidate
3.Atomoxetine - Guanfacine
- Clonidine
which of the ADHD medications are stimulants
- Dexamfetamine / lisdexamfetamine
2.Methylphenidate
which of the adhd medications are non stimulant
3.Atomoxetine
4. Guanfacine
5. Clonidine
what is occassionally used off licence for adhd and its mechanism
Bupropion
dopamine reuptake inhibitor
where are therapeutic effects for adhd known to take place
prefrontal cortex
noradrenaline»_space;
which mechanism do each ADHD medication work by
- Increases synaptic levels of dopamine and noradrenaline- dexamfetamine/lidexamfetamine/methylphenidate
- Increasing NA levels in the synaptic cleft -
highly selective norepinephrine reuptake inhibitot
- atomoxetine - Selective agonist of α2A-adrenergic receptors. Binds to postsynaptic α2A-adrenergic receptors, mimicking NA - guanfacine
- clonidine- agonist of α2-adrenergic receptors, mimic NA
Dexamfetamine / lisdexamfetamine contraindications
Significant cardiovascular disorders
Cerebrovascular disorders
Use of MAO inhibitors
Hx of drug abuse
Hyperthyroidism
Glaucoma
Porphyria **
Gilles de la Tourette syndrome or similar dystonias **
Pregnancy and lactation **
Psychosis or bipolar I (if not well controlled)
Anorexia
Significant suicidal ideation
s/e of dexamfetamine /lisadexamfetamine
interactions
decreased appetite
- reduced weight gain and weight loss during prolonged use in children
- insomnia
- nervousness
minimal impact with CYP
contraindications for methylphenidate
significant cardiovascular disorders
Cerebrovascular disorders
Glaucoma
Phaechromocytoma
Use of MAO inhibitors
Psychosis or bipolar I (if not well controlled)
Anorexia
Significant suicidal ideation
Hyperthyroidism or thyrotoxicosis
methylphenidate s/e and interactions
decreased appetite
- insomnia
- nervousness
- headache
- nausea
- dry mouth
nil - No significant effect on CYP
s/e and interactions of Atomoxetine
appetite decreased
- headache
- somnolence
- abdominal pain (includes epigastric discomfort)
- vomiting
- nausea
- blood pressure increased
- heart rate increased
metabolised by CYP2D6
CI, s/e and interactions of guanfacine
contradindications nil
S/E
somnolence (40%)
- headache (27%)
- fatigue (18%)
- abdominal pain (12%)
Interaction with
Can increase levels of valproic acid
metablised by CYP3A4/5
clonidine
CI
S/E
Interaction
ci Severe bradyarrhythmia resulting from either sick-sinus syndrome or AV block of 2nd or 3rd degree
s/e
dizziness
- sedation
- orthostatic hypotension
- dry mouth
No significant effect on CYP
Much of the drug excreted unchanged in urine
what is important to note about methylphenidate ?
relative constitution of various brands of methylphenidate vary
immediate and long acting
Which ADHD medication can have more impact on BP
which receptor?
. Clonidine has more effect on α2B receptors which are located on blood vessels and this can lead to more pronounced effects on blood pressure compared to guanfacine.
how does methylphenidate work specifically?
it blocks DAT and NAT receptors (dopamine transporter) and noradrealine transporter to increase levels in synaptic cleft
how does dexamfetamine differ to methylphenidate?
has same mechanism as methylphenidate but ALSO
blocks SERT (serotonin transporter).
- promotes release of monoamines from the presynaptic neurone into the synapse
what can ADR be split into?
what percentage of which>
Type A (80%)
and B
A pharmcological
B(Idiosyncratic Reactions)
Type B reactions cannot be predicted from the known pharmacology of the drug. They are often unrelated to the drug’s intended pharmacological action. Allergic reactions fall under this category. Type B reactions can be more challenging to anticipate or prevent.
what is a key category for type B reactions?
Allergies
what classification/criteria is used for allergies?
Gell and Coomb
What are the subtypes for allergies
type I -IgE - immediate hypersensitivity reactions
Type II (Cytotoxic) -
Type III immmune complexes
Type IV cell mediated
examples of each immune reaction and times
pe I -IgE - immediate hypersensitivity reactions - anpylhaxis seconds minutes after
Type II (Cytotoxic) - drug-induced haemolytic anaemia or thrombocytopenia. The timing of these reactions is variable.
Type III immmune complexes serum sickness or drug-induced lupus. These usually occur 1 to 3 weeks after exposure.
Type IV cell mediated -days or even weeks later . Contact dermatitis and some forms of drug-induced hepatitis are examples.
mechanism of subtype for immune mechanism
type I -IgE - immediate hypersensitivity reactions mediated by the IgE antibody. They can lead to symptoms such as hives, itching, swelling, and in severe cases, anaphylaxis. minutes after exposure
Type II (Cytotoxic) - actiation of complement proteins and destruction of cells by antibodies
Type III immmune complexes, which are antigen-antibody aggregates, can form and deposit in tissues, leading to inflammatio
Type IV cell mediated These reactions are mediated by T cells and occur over a delayed period, often days to weeks after exposure to the drug.
what is Agomelatine ? receptors?
agonist at melatonin M1 and M2 receptors and as an antagonist at 5HT2C receptors.
used to treat depression