Lithium - 1 Flashcards
Lithium mechanism of action at neural level?
reduces excitatory (dopamine and glutamate)
increases inhibitory (GABA) neurotransmission
increases serotonin transmission by increasing serotonin synthesis, uptake, and release
neuroprotective action of lithium?
Lithium may reduce oxidative stress and increase protective proteins, such as brain-derived neurotrophic factor and B-cell lymphoma 2
Does Lithium reduce suicidality?
Yes by 80%
Why lithium is better for prophylaxis rather than in acute mania?
Because it takes a week to show effect
effect of lithium on mania as prophylactic?
- reduces severity
-reduces the number of relapses
does lithium have different effect on manic bipolar or the depressive episodes?
manic episodes
Lithium protects against antidepressive induced hypomania. True or false
True
Lithium is shown to be effective as augmentation in unipolar depression. True or false?
True!!!again!!!
Non- bipolar situation where lithium has been used?
-augmentation Rx in unipolar depression
-Aggressive or self-mutilating behaviours
-Steroid-induced psychosis
-To raise WBC in clozapine users
Pre-Prescription test in Lithium therapy?
-ECG (cardiology)
-U&E (kidney)
-TFT (Thyroid)
Extra pre-prescription test suggested by BNF?
- BMI
+
-Full blood count
Lithium in women childbearing age?
-Advised reg. contraception
-informed about toxicity
what dosing frequency is preferred for lithium?
once daily
when is usually lithium given?
at night
Example of lithium preparation?
Priadel
Liskonum
What is the risk of abrupt discont. of lithium?
R e l a p s e
Minimum duration for tapering lithium?
at least 4 week
at least 1 month
at least over 30 days
Preferred duration for lithium discontinuation?
3 months
12 weeks
90 days
a quarter of year
over one season
Inadequate Lithium monitoring is rare. True or false?
False.
It is common
BNF suggestion for Lithium level monitoring
1- Weekly until dose is stabilised (upon initialising or changing dose)
2- Every 3 months for the first year
3-Every 6 months
BNF Suggestion for more frequent lithium monitoring?
->65 years old
-co-drugs with potential interaction
-Impaired Renal & Thyroid
-Raised Calcium or other complications
-Poor symptom control
-Poor adherence
-Last lithium serum level .8 mmol/L or more
BNF suggestion for extra items to be monitored beside lithium level?
BMI
Thyroid function test
Serum electruid ]====> every 6 months
eGFR
How long after last dose, lithium level should be taken?
12 hours later
(10-14 hours is still reasonable)
BNF suggested a therapeutic lithium level?
- 0.4-1 mmol/L
BNF suggested therapeutic lithium level for maintenace and elderly?
Around 0.4 mmol/L
BNF suggested a therapeutic lithium level of 0.8-1 mmol/L.
- Acute mania
-Hx of Relapse
-Sub-syndromal symptoms
Maudsley Suggests the minimum adequate plasma level of lithium for prophylaxis.
0.4 mmol/L
Maudsley Suggestes the Optimal adequate plasma level of lithium for prophylaxis?
0.6 - 1.2 mmol/L
Maudsley Suggestes the Protective plasma level of lithium against mania (prophylaxis?
> 0.75 mmol/L
Maudsley Suggestes the TARGET adequate plasma level of lithium for prophylaxis?
0.6 - 0.75 mmol/L
0.4 mmol/L
Maudsley Suggests the minimum adequate plasma level of lithium for prophylaxis.
0.6 - 1.2 mmol/L
Maudsley Suggestes the Optimal adequate plasma level of lithium for prophylaxis?
> 0.75 mmol/L
Maudsley Suggestes the Protective plasma level of lithium against mania (prophylaxis?
0.6 - 0.75 mmol/L
Maudsley Suggestes the TARGET adequate plasma level of lithium for prophylaxis?
what medication class can mess up lithium level?
NSAIDS
ACE inhibitors
Diuretics
Risk F a c t o r s to cause lithium toxicity?
- Drug interactions
-Fever
-Infections
-Reduced circulating volume
-Dehydration
-Nephrogenic Diabetic Insepidus
Drugs that increase Lithium Level?
NSAIDs (Aspirin)
COX-2 inhibitors (Celecoxib)
Thiazide (bendroflumethiazide)
ACE inhibitors (Captopril, ramipril)
Drugs that have no effect on lithium but work in kiney?
Loop diuretics (Furosemide, bumetanide, and torsemide)
Division of lithium toxicity
GIT
Neurology
GIT features of lithium toxicity
Nausea
Vomitting
Diarrhoea
Abd. cramps
Neurology related features of lithium toxicity?
- Coarse Tremor
-Seizure - Dystonia
- Ataxia
-Nystagmus
-Hyperreflexia
-confusion
What scale is used to measure lithium toxicity?
AMDISEN
Ratings on MDISEN = score 0
No signs or symptoms?
Ratings on MDISEN = score 1
Mild symptoms
Nausea
Vomiting
Tremor
Hyperreflexia
Agitation
Weakness
Ataxia
Ratings on MDISEN = score 2
Moderate
Ratings on MDISEN = score 3
Severe
Cardiovascular
Coma
Seizure
Myoclonus
what is metabolite of lithium called?
Lithium has no metabolite
It is not metabolized.
Does Lithium bind to any protiens?
no
it roams free
what congenital disease is thought to be associated with Lithium
Ebstein’s (had not held to be true recently)
what is Ebstein’s?
Prolapse of the tricuspid valve into the right ventricle
incidence of Ebstein’s?
1:20’000 of general population
mnemonic of Lithium contraindications?
BAC LUC
Contraindications for lithium?
BAC LUC
- Brugada disease
-Addison’s disease
-Cardiovascular (arrythmia)
-Low sodium
-Untreated hypothyroidism
-Clinical signif. renal failure
A patient on lithium comes in with nausea…what do you think caused it?
it might be related to the peak of the dose…divide the dose into two or three to reduce the peak
prognosis for lithium induced nausea
may diminish over time
what if lithium - induced - nausea was accompanied by vomitting?
it is probably due to toxicity not just a side effect
what can cause lithium-induced polydipsia + polyurea?
ADH insensitivity
What do think about fine tremor in lithium therapy (fine, not coarse)?
-Symmetric
-indistinguishable from physiologic or essential one
-most apparent with intentional activities (holding a cup)
Onset of fine tremor in lithium therapy?
Early
Is Fine tremor in lithium therapy dose dependent?
Yep
what can help with fine tremor in lithium therapy?
Beta Blockers
Risk for developing fine tremor in lithium therapy?
old age
paradoxical side effect of lithium therapy?
weight gain despite loss of appetite
other side effects of lithium therapy?
- drowsiness
-Metalic taste
-Diarhoea
-Muscle weakness
True or false:
Lithium side effects are usually not dose dependent?
False
They are usually dosedependent
Long Term Side effects of Lithium therapy
-Hypo-/Hyper thyroidism
-Hypercalcaemia/Hyperparathyroidism
-Irreversible Nephrogenic diabetic insipides
-Reduced GFR
what is nephrogenic diabetic insipidus (DI) resulting in?
inability of kidneys to concentrate urine
how does lithium causes DI?
it causes dysregulation of principal cells in short term
it causes loss of principal cell in long term
How to treat DI caused by lithium therapy? Lithium wise
Stop lithium if possible
if not, keep level (0.4-0.8 mmol/L)
Take once-daily dose
Medications that can help in Lithium induced DI?
Amiloride (k sparing)
Thiazide diuretics
Indomethacin
Desmopressin
How indomethacin helps in lithium induced DI?
It blocks prostaglandin activity, which augments the action of ADH on principal
(remember lithium-induced ADH sensitivity)
How does amilorides help in lithium induced DI?
Amiloride (K sparing) block Na channels and stop lithium going inside principle cells.
