HIGH RISK DRUGS Flashcards by Ruby M

What are the CI of lithium?

Addison’s disease
Cardiac insufficiency 
Dehydration 
Low Na+ diet 
Untreated hypothyroidism

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What are cautions of lithium?

Avoid abrupt withdrawal 
Cardiac disease 
Concurrent ECT (May lower seizure threshold)
Epilepsy
Qt prolongation 
Can exacerbate psoriasis

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What is the association with long term use of lithium?

Thyroid disorders
Mild cognitive and memory impairment

Patients should b maintained on lithium after 3-5 years only if benefit is ther.

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What are the signs of overdose of lithium?

GI disturbances:(vomiting and diarrhoea)
visual disturbances (blurred vision)
CNS disturbances: (fine tremors increasing to coarse, confusion, drowsiness, lack of co-ordination, restlessness, stupor, high Na+, incontinence)

Severe overdosage:( >2mmol/L)

Seizures 
Cardiac arrhythmia (bradycardia, heart block)
BP changes 
Circulatory failure 
Renal failure
Coma 
Sudden death

STOP TREATMENT IMMEDIATELY

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What is the conception, contraception advice and pregnancy advice with lithium?

Effective contraception during treatment

Avoid during pregnancy, especially in the 1st trimester (risk of teratogenicity and cardiac abnormalites)

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What are the serum level monitoring requirements of lithium?

-Serum concs: 0.4-1mmol/L
(lower end of the range for maintenance and the elderly)
Blood samples should be taken 12 hours.

0.8-1mmol/L: acute episodes of mania and relapse patients and sub-syndromal symptoms

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When should serum levels of lithium be measured?

Weekly after initiation and after each dose change until concs are stable.
Then every 3 months thereafter.

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What are the other factors that should be monitored for lithium?

Asses renal, cardiac, and thyroid function before treatment initiation.

Cardiac function- regularly

ECG is recommended in patient with CVD or risk factors.

FBC can be measured before treatment
-BMI or body weight, serum electrolytes, thyroid, eGFR before starting and every 6 months.

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What advice should be given when stopping lithium treatment?

Do not stop immediately unless told by dr.

Dose should be reduced gradually over at least 4 weeks (preferably over 3 months)

Abrupt withdrawal increases risk of relapse.

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What are the patient/career advice for lithium?

Patients should stay on one brand
They have have the treatment pack
Keep constant and adequate salt and water intake (especially if they have an infection or during hot spells)
Avoid otc NSAIDs, alcohol and Na+ containing antacids
Risk of feeling sleepy- be careful when driving.

Report signs of benign intracranial HTN, hypothyroidism, renal dysfunction

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What drugs increase the toxicity of lithium?

ACEI, ARBS
Loop diuretics, thiazides 
NSAIDS
K + sparing diuretics 
SSRIs (and CNS effects)
TCAs
Aldosterone antagonists

Metronidazole (MAY increase risk of toxicity)

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What drug increases risk of ventricular arrhythmias For lithium?

Amiodarone

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What drugs increase the risk of neurotoxicity of lithium?

Methyldopa
Phenytoin
Carbamazepine 
Diltiazem
Verapamil

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What is the target rage for carbamazepine?

4-12mg/L measure after 1-2 weeks therapy

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What are the monitoring requirements of carbamazepine?

FBC
Renal function
Liver function

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What are the warning signs of carbamazepine?

Toxicity: incoordination, blurred vision, Diplopia (double vision), Nystagmus, Ataxia, Arrhythmia, N + V, Low Na+, Diarrhoea. STOP TREATMENT!

Blood disorders: leucopenia, thrombocytopenia (fever sore throat, fever, bruising)

Skin disorders: Toxic epidermal necrolysis (rash)

Hepatic disorders

Antiepiletic hypersensitivity syndrome: feve, rash, swollen lymph nodes.

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What is the major route of Elimination of carbamazepine?

Hepatic metabolism

Cyp450 enzyme inducer

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Which vitamin is recommended in carbamazepine and phenytoin? And for which type of patients?

Vit D 
Consider in patients:
-who are immobilised for long periods 
-have inadequate sun exposure
-have inadequate dietary intake

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Which pre-treatment screening test is recommended in both carbamazepine and phenytoin and why?

Test for HLA-B*1502 allele in patients of Han Chinese or Thai origin due to the risk of SJS

For the treatment of bipolar disorder, what is the withdrawal advice for carbamazepine?

Gradual withdrawal over at 4 weeks

What are the patient/ career advice with carbamazepine?

report any warning signs to the doctor immediately
same brand all the time: (CATEGORY 1, like phenytoin, primidone, phenobarbital)
DVLA advice

What drugs increase the levels of carbamazepine?

Cimetidine
Clarithromycin 
Erythromycin 
Isoniazid 
Fluoxetine

What drugs decrease the levels of carbamazepine?

phenytoin
Rifabutin
St. John’s wort

What drugs does carbamazepine reduce the levels of?

Antipsychotics 
Corticosteriods 
Coumarins
Eplerenone 
Oestrogens + progesterones 
Simvastatin

What is the drug interaction between orlistat and carbamazepine?

Increased risk of convulsions

What are the target ranges of ciclosporin?

Depends on clinical situation and indication for treatment.

What are the monitoring requirements of ciclosporin?

- Ciclosporin blood serum levels- refer to local guidance - Full blood count - LFTs - Serum K+ (risk of hyperkalaemia)and Mg2+ - eGFR - BP: DISCONTINUE if HTN develops and cannot be controlled by antihypertensives - Blood lipids (cholesterol) In long-term MGT of nephrotic syndrome, perform renal biopsies EVERY YEAR

When treating severe psoriasis or atopic dermatitis with ciclosporin, what are the monitoring requirements and how many times should it be tested?

Measure: -Dermatological and physical examinations -eGFR, creatitine (renal function) - EVERY 2 WEEKS for first 3 months, then EVERY MONTH, then. Every 4-8 weeks -BP Measure ALL at least TWICE before initiation

What ids the MHRA/CHM advice on ciclosporin

Patient should be kept on the same brand. Switching can lead to clinically significant blood serum levels

What are the warning signs of ciclosporin?

- Neurotoxicity (tremor, headache, encephalopathy) - blood disorders - liver toxicity - nephrotoxicity (e.g. elevated serum creatinine concs) - vomiting, drowsiness, tachycardia - HTN - Headache - Gingivial hyperplasia.

What are the patient/carer advice for ciclosporin?

- HTN is a common SE: have regular BP monitoring - warn patients not to receive live vaccines - patient should excessive exposure to UV light. Broad spec sunscreen should be used. - Patients with atopic dermatitis should avoid the use of UVB or PUVA. - AVOID high K+ diet and grapefruit juice. - oral solution formulations can be taken with orange or apple juice to improve taste.

What is the further information in relation to adrenal suppression and corticosteroids?

Abrupt withdrawal after long term use can lead to adrenal insufficiency, hypotension and death. -patients on long term steroids should have a steroid treatment card

What is the further information in relation to infections and corticosteroids?

- Prolonged use increased suspectiblity to infections and severity of infections. - serious infections

What is the target range for phenytoin?

10-20mg/L (40-80micromol/L)

What do you do if a patient is given enteral feeding and is taking phenytoin at the same time?

Interrupt enteral feeding for 2 hours BEFORE AND AFTER dose

What are the signs and symptoms of phenytoin toxicity?

SNACHD - Slurred speech - Nystagmus - Ataxia - Confusion - Hyperglycaemia - Diplopia

What are the patient and carers advice for phenytoin in relation to SEs?

Blood and skin disorders can occur. Seek IMMEDIATE medical attention for leucopenia, anaemia, fever, sore throat, mouth ulcers, unexplained bleeding Skin (SJS): rash, toxic epidermal necrolysis

What are the specific SEs with oral use of phenytoin?

- Electrolyte imbalance - Vit D deficiency - pneumonicitis

Can phenytoin cause renal or hepatic impairment and what are the instructions?

HEPATIC IMPAIRMENT | -Reduce dose to avoid toxicity

How does azathioprine work?

It’s metabolised to mercaptopurine

What is the dose adjustment when azathioprine is given with allopurinol?

Reduce azathioprine dose to 1/4 (one-quarter)

What are the monitoring requirements of azathioprine?

-monitor for toxicity throughout treatment -monitor full blood count WEEKLY for the first 4 weeks, then reduce down to at least every 3 months - this is ESSENTIAL for signs of myelosuppression -TPMT activity measure B4 INITIATION (thiopurine methyltransferase). Low activity = HIGH risk of myelosuppression Zero activity = AVOID

What are the main SEs in azathioprine?

1. Neutropenia and thrombocytopenia (bleeding, bruising) 2. Hypersensitivity reactions (malaise, dizziness, vomiting, diarrhoea, fever, rash, myalgia, HYPOtension, renal dysfunction)WITHDRAW 3. N+V (Nausea is common early on in the treatment. Usually resolves after a few weeks without alternating the dose) MODERATE nausea can be managed by dividing dose, taking doses after food, prescribing antiemetics, temporarily reducing dose

What are the dose requirements for elderly when taking azathioprine?

Reduce the dose in elderly

When azathioprine is used to treat rheumatoid arthritis when do you WITHDRAW?

When N+V or diarrhoea occurs it may be appropriate to STOP