Class 5- bipolar Flashcards
Drugs and drugs that can precipitate a
manic episode
• Stimulants or hallucinogens
• Antidepressants
• Hormones
(synthroid, corticosteroids)
MOOD STABILIZERS definition
Efficacy either in treating manic or depressive symptoms, without causing any switch of polarity (e.g. lamotrigine)
Li is a
Monovalent cation
Li
CLINICAL USE
o Bipolar disorder
o Schizo-affective disorder
o Major depressive disorder (adjunctive medication)
o Neutropenia secondary to clozapine (to increase
leukocytes)
Li Contraindications
- Breastfeeding
- Brain damage
- Heart failure and other heart disease
- Kidney failure
Absorption Li
Good absorption through the gastrointestinal tract
Distribution Li
Distributed in body water
Metabolism Li
Not metabolized by the liver so no interaction with cytochrome
Elimination Li
o Almost totally through the kidneys
o Large proportion is reabsorbed by the proximal tubule
o Elimination related to glomerular filtration rate
• Age
• Creatinine clearance
Half-life time Li
o 8 to 35 hours (24h)
o Steady state reached in 5 days
DOSING Li
o Gradual increase
o Often administered BID to TID at the beginning of the treatment
• In order to reduce the “peaks” of plasma concentration
• Less GI side effects
o Adjust dose according to serum concentration
o Once the target dose is reached, lithium can be administered once daily (HS)
Therapeutic interval Li
0,6 – 1,2 mmol/L
Therapeutic interval Li acute
0,8 – 1,2 mmol/L
Therapeutic interval Li maintenance
0,6 – 1 mmol/L
Therapeutic interval Li elderly
0,6 – 0,8 mmol/L
Li, At steady state, when the dose is changed, the serum concentration should change ???
proportionally
LITHIUM CONCENTRATION IN BLOOD CELLS why use
Could potentially better predict the toxic effects of lithium
sign of intoxication Lithium in blood cells
> 0,6 mmol/L
STARTING LITHIUM
- Lithium 300 mg BID days 1 to 3
- Lithium 450 mg BID days 4 to 5
- Serum dose of lithium on the day 10 or 11
• Steady state about 5 days after last dose increase
• If < 0.6 mmol/L, increase the dose
• If between 0.6 and 1.2 mmol/L, contrôle serum dosage within a week (if hospitalized) or in two weeks (if outpatient)
MECHANISM OF ADVERSE EFFECTS Li
It replaces sodium (Na) in transmembrary
exchanges
SIDE EFFECTS Li
v ACNE - Up to 33% of patients - Development or worsening of acne v PSORIASIS v ARRYTHMIAS v CHANGES TO THE ECG, QTC PROLONGATION - Especially in case of intoxication v NAUSEA - Especially at the beginning of treatment v DRY MOUTH, THIRST - Up to 75% of patients v POLYURIA - About 30% of patients - Reduce serum lithium concentration - Use once a day - Investigating nephrogenic insipid diabetes v KIDNEY DAMAGE - Especially in case of intoxication - In rarer cases: epithelial tubular damage, acute tubular necrosis, nephrotic syndrome v CHRONIC KIDNEY FAILURE? - Gradually appears over the years - Very rare end-stage kidney failure (0.2 to 1% of patients receiving lithium for > 15 years) v HYPOTHYROIDISM - 8 - 19% of patients, may be irreversible - Not a contraindication to start lithium v HYPERPARATHYROIDISM - Recommended basic calcium level, then tracked - If hypercalcemia à PTH v WEIGHT GAIN - Especially at the beginning of treatment - 4 -6 kg v LEUKOCYTOSIS - Often benign v FINE TREMORS - Related to blood concentration; reduce the dose - Add propranolol 10 - 30 mg BID - TID v OTHER CONCENTRATION-DEPENDANT EFFECTS - Delirium, confusion, convulsions, coma
RISK FACTORS FOR DEVELOPING CHRONIC KIDNEY FAILURE on Li :
- High lithium levels
- Multiple lithium poisonings
- Several takes a day (taking once a day, trough post 12 h isn’t at true lowest)
- Concurrent medication (e.g. AINS, IECA/ARA, diuretics): all the ampril and sartan
- Comorbidities (e.g. high blood pressure, diabetes)
- Age
Toxicity Li 1,5 – 2 mmol/L
Diarrhea, vomiting, drowsiness, muscle weakness,
decreased coordination
Toxicity Li 2 – 2,5 mmol/L
Ataxia, blurred vision, ringing in the ears, change to the
ECG
Toxicity Li> 3 mmol/L
Changes neurology, coma
Acute intoxication on chronic intoxication Li
= potentially fatal
Possible permanent neurotoxicity: memory impairment, ataxia, dysarthria and tremors
TOXICITY
TREATMENT Li
o Stop lithium
o Gastric washing if lithium intake is recent
o Maintain volemia and electrolytes.
o Activated charcoal does not adsorb lithium, but can be administered if polyintoxication is suspected.
o Dialysis is effective and may be necessary for cases with target organ damage.
↑ LITHIUM CONCENTRATION interaction
- NSAID
- Diuretics
- Angiotensin Conversion Enzyme Inhibitors (IECA)
- Angiotensin II receptor antagonists (ARA)
- Alcohol (dehydrates)
↓ LITHIUM CONCENTRATION interaction
- Table salt
* Theophylline
PATIENT EDUCATION Li
HE NEEDS TO KNOW THE INTERACTIONS Products that stimulate urine production Risk of dehydration Drugs for pain (NSAID) Acétaminophène (TylenolTM) is safe Beware of medications used to treat cold Some antihypertensives Alcohol Always consult a health care professional before purchasing a new drug (prescription or over-thecounter) Proper hydration Diarrhea or vomiting=Rehydration STAT Sweating (Heatwave, physical exercise)
Before treatment protocol Li
o Recent physical examination
o FSC, urea, creatinine, electrolytes, calcium, TSH, urine analysis, b-hcg and fasting blood sugar, weight
o ECG if > 40 years old
During treatment protocol Li
o TSH q3 month x 2 years then q6 months
o Every year: FSC, urea, creatinine, electrolytes, total calcium, urine analysis, fasting blood sugar,
weight
o Vital signs at each serum dosage
FREQUENCY OF SERUM DOSAGE Li
-Initiation of treatment
• 1 to 2 times a week depending on the titration ad stabilization
• 1 to 2 times a month for a month
-Maintenance treatment
• q3 month x 2 years, q6 months thereafter
-In the following cases :
• prescription modification, addition of concurrent treatment, doubts about adherence, signs and
symptoms of toxicity, drug interactions or clinical situation warrants it
Valproic acid / Divalproex class
anticonvulsants