sodium valproate + lithium Flashcards
what is the only indication where a female may be allowed to take sodium valproate during pregnancy
Epilepsy
- Use of valproate in pregnancy is contra-indicated for migraine prophylaxis [unlicensed] and bipolar disorder; it must only be considered for epilepsy if there is no suitable alternative treatment
when dispensing a sodium valproate prescription for a female, how often should the pharmacist discuss the risks in pregnancy
each time valproate medicines are dispensed
- also ensure they have a patient card
- note pharmacist also need to ensure they have the Patient Guide and have seen their GP or specialist to discuss their treatment and the need for contraception. but this is not everytime valproate is dispensed*
how often do female patients taking sodium valproate need to be reviewed by a specialist
annually
note review ensures women are on pregnancy prevention programme (PPP) and re-evaluates to see if treatment is necessary
what are the contraindications for sodium valproate
- Acute porphyrias (liver disorder which causes porphyrins to build up in the liver. There are different types but acute porphyrias affects the nervous system)
- known or suspected mitochondrial disorders (higher rate of acute liver failure and liver-related deaths)
- personal or family history of severe hepatic dysfunction
- urea cycle disorders (risk of hyperammonaemia)
Although raised liver enzymes during valproate treatment are usually short term, how long should you monitor liver function for
- reassessed clinically and liver function (including prothrombin time) monitored until results return to normal
- discontinue if abnormally prolonged prothrombin time (particularly in association with other relevant abnormalities))
what should you do if a patient taking sodium valproate has a prolonged prothrombin time
discontinue treatment
name some common side effects of sodium valproate
- hepatic disorders
- hypersensitivity
- hyponatremia
- Abdominal pain
- agitation
- alopecia (regrowth may be curly)
- abnormal behaviour
which symptoms indicate you need to withdraw sodium valproate treatment immediately
Withdraw treatment immediately if persistent vomiting and abdominal pain, anorexia, jaundice, oedema, malaise, drowsiness, or loss of seizure control
what should you do if a patient taking sodium valproate starts to show symptoms of pancreatitis
name some symptoms of pancreatits
discontinue treatment
symptoms of pancreatitis:
- suddenly getting severe pain in the centre of your tummy (abdomen)
- feeling or being sick
- diarrhoea
- a high temperature of 38C or more (fever)
if sodium valproate is used during pregnancy, describe how the doses should be given
- the lowest effective dose should be prescribed in divided doses or as modified-release tablets to avoid peaks in plasma-valproate concentrations
- doses greater than 1 g daily are associated with an increased risk of teratogenicity
how do you avoid peaks in plasma-valproate concentrations in pregnant women taking sodium valproate
the lowest effective dose should be prescribed in divided doses or as modified-release tablets to avoid peaks in plasma-valproate concentrations
what is the risk associated with breastfeeding whilst taking sodium valproate
sodium valproate is present in milk—risk of haematological disorders in breast-fed newborns and infants
TRUE OR FALSE
it is advised to avoid sodium valproate in hepatic impairement
true
why is routine monitoring of the Plasma-valproate concentrations unhelpful
Plasma-valproate concentrations are not a useful index of efficacy
what monitoring should occur for patients taking sodium valproate
- Monitor liver function before therapy and during first 6 months especially in patients most at risk
- Measure full blood count and ensure no undue potential for bleeding before starting and before surgery
how do you withdraw sodium valproate treatment
Avoid abrupt withdrawal; if treatment with valproate is stopped, reduce the dose gradually over at least 4 weeks
do patients taking sodium valproate need to be given the same/specific manufacturers brand
sodium valproate = stage 2 so whether or not a patients needs a specific manufacturer is:
based on clinical judgement and consultation with the patient or their carer, taking into account factors such as seizure frequency and treatment history.
when should patients taking sodium valproate seek immediate medical attention
if they develop symptoms of:
- blood disorders (fever, infections, fatigue, abnormal bleeding)
- liver disorders (jaundice, dark urine, tenderness/pain in liver area, nausea + vomiting, pale colour stool or very dark stools)
- pancreatitis such as abdominal pain, nausea, or vomiting develop
TRUE OR FALSE
preparations of lithium are dose equivalent
FALSE
Preparations of lithium vary widely in bioavailability; changing the preparation requires the same precautions as initiation of treatment
name the contraindications for lithium
- Addison’s disease (reduced cortisol/ aldosterone due to faulty adrenal glands)
- cardiac insufficiency
- dehydration
- low sodium diets
- untreated hypothyroidism
what are the risks associated with long term use of lithium
- Long-term use of lithium has been associated with thyroid disorders and mild cognitive and memory impairment.
Monitor thyroid function every 6 months (more often if there is evidence of deterioration).
name some of the symptoms of lithium toxicity
- increasing GI disturbances (vomiting, diarrhoea)
- visual disturbances
- polyuria (excess urine production), incontinence (partial or complete loss of bladder control)
- fine tremor increasing to coarse tremor
- CNS disturbances (confusion and drowsiness increasing to lack of coordination, restlessness, stupor);
- myoclonus (involuntary muscle jerks),
if there is a severe overdose symptoms are:
- cardiac arrhythmias (including sinoatrial block, bradycardia and first-degree heart block)
- renal failure
- coma and sudden death reported
TRUE OR FALSE
women of child-bearing age taking lithium MUST be on contraception
FALSE
effective contraception is advised but not mandatory
describe how lithium treatment is managed in pregnant women
- Avoid if possible, particularly in the first trimester (risk of teratogenicity, including cardiac abnormalities)
- Dose requirements increased during the second and third trimesters (but on delivery return abruptly to normal)
- ensure close monitoring of serum-lithium concentration in pregnancy
which trimester should pregnant women avoid taking lithium and why
avoid taking lithium in the first trimester because there is a risk of teratogenicity including cardiac abnormalities
why should women avoid breastfeeding whilst taking lithium
because lithium is present in breast milk so there is a risk of toxicity to the infant
what monitoring should occur for patients taking lithium
- body-weight or BMI
- serum electrolytes
- serum-lithium monitoring
- eGFR and thyroid function every 6 months
describe how to withdraw lithium treatment
- the dose should be reduced gradually over a period of at least 4 weeks (preferably over a period of up to 3 months). This is because abrupt withdrawal increases risk of relapse
- if lithium is stopped abruptly, consider changing therapy to an atypical antipsychotic or valproate.
why should patients taking lithium maintain adequate fluid intake and avoid dietary changes
because changing your diet or not having enough fluid intake can increase or decrease sodium levels intake. Low sodium diets are contraindicated for lithium
what signs and symptoms should you advise patients to report whilst taking lithium
report signs and symptoms of:
- lithium toxicity
- hypothyroidism
renal dysfunction (including polyuria - excess urine production and polydipsia- excessive thirst) - benign intracranial hypertension (persistent headache and visual disturbance).
what is the therapeutic range of serum-lithium concentration
ideal serum-lithium concentration of 0.4–1 mmol/litre
lower end of the range for maintenance therapy and elderly patients
what is lithium used for (indications)
Treatment/prophylaxis of mania, bipolar disorder, recurrent depression, aggressive or self-
harming behaviour
