Mood stabilisers Flashcards
What is the MOA of lithium?
Largely unknown, but its actions include inhibition of dopamine release, enhancement of serotonin release and decreased formation of intracellular second messengers. Lithium has little or no psychotropic effect in normal individuals.
What do you need to be cautious of when using lithium?
Hyponatraemia (increases risk of toxicity)
Hypothyroidism (treat before starting, because lithium can cause / exacerbate this)
Psoriasis (exacerbated or precipitated by lithium)
Pregnancy (increase congenital heart defects.
What are the ADRs / complications of lithium?
Arrhythmias, thyriod problems, nystagmus
Nephrotoxic (nephrogenic diabetes insipidus, and nephropathy)
Toxicity:
Mild-mod: Blurred vision, diarrhoea, N/V, ataxia, URTI symptoms
Severe: Increased muscle tone, hyperreflexia, myoclonic jerks, coarse tremor, psychosis, seizures, coma
What is the normal dose for Lithium in the treatment of acute mania?
750-1000mg daily in divided dosage (Quilonum SR)
Increase by 250-500mg as needed (adjust according to serum concentration)
What is the normal dose for Lithium when used for prohylaxis?
250-1000mg per day in divided dosages (Quilonum SR)
Adjust dose according to serum concentration
What are the serum concentration targets for Lithium?
Acute mania - 0.5-1.2mmol/L
Prophylaxis - 0.4-1.0mmol/L
What are the general pharmacological treatments for Bipolar disorder?
Lithium is the drug of choice for treatment and prophylaxis of acute mania.
Valproate and carbamazepine are used as alternatives when lithium is considered too dangerous (in unreliable patients) or is poorly tolerated or ineffective; they are sometimes used with each other or with lithium. Carbamazepine concentration correlates poorly with effect on mood, but evidence suggests that the valproate concentration needed is similar to that used for seizure disorders. Valproate and carbamazepine also appear to be particularly suitable for those with rapid cycling illness (4 or more episodes a year). Lamotrigine may also be considered for depressive episodes or maintenance treatment (concentration monitoring is not required).
What is the MOA for sodium valproate?
Prevents repetitive neuronal discharge by blocking voltage‑ and use-dependent sodium channels.
Other actions include enhancement of GABA, inhibition of glutamate and blockade of T-type calcium channels.
What is the normal dosage for Sodium valproate in Bipolar disorder?
initially 600 mg daily in 2 doses; increase every 3 days by 200 mg daily according to response.
What is the MOA for Carbamazepine?
Prevents repetitive neuronal discharges by blocking voltage-dependent and use-dependent sodium channels.
What are the contraindications for Sodium valproate?
(HUMPP) Hypersensitivity Urea cycle disorders Mitochondrial disorders with mutations in POLG gene (Alpers-Huttenlocher syndrome) Pancreatic dysfunction Porphyria
What are the contraindications of Carbamazepine?
AV conduction abnormalities
History of bone marrow depression
Porphyria
What are some considerations when using Carbamazepine?
Absence and myoclonic seizures (increases seizures)
Treatment with levothyroxine (increases metabolism –> increases breakdown)
Treatment with Clozapine (increases risk of serious haematological ADRs)
What is the most significant ADRs of Carbamazepine
Aplastic anaemia
Multi-organ hypersensitivity syndrome
What is multi-organ hypersensitivity syndrome?
Rare allergic reaction:
Early symptoms may include rash (may be severe), fever, lymphadenopathy and haematological abnormalities (eg eosinophilia).
It may affect the liver, kidneys and lungs and can lead to hepatic or renal failure.
Stopping the drug and treating with corticosteroids usually improves symptoms. Do not restart the drug.
