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Flashcards in HIGH RISK DRUGS Deck (45)
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1
Q

What are the CI of lithium?

A
Addison’s disease
Cardiac insufficiency 
Dehydration 
Low Na+ diet 
Untreated hypothyroidism
2
Q

What are cautions of lithium?

A
Avoid abrupt withdrawal 
Cardiac disease 
Concurrent ECT (May lower seizure threshold)
Epilepsy
Qt prolongation 
Can exacerbate psoriasis
3
Q

What is the association with long term use of lithium?

A

Thyroid disorders
Mild cognitive and memory impairment

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

4
Q

What are the signs of overdose of lithium?

A
  • 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

5
Q

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

A

Effective contraception during treatment

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

6
Q

What are the serum level monitoring requirements of lithium?

A

-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

7
Q

When should serum levels of lithium be measured?

A
  • Weekly after initiation and after each dose change until concs are stable.
  • Then every 3 months thereafter.
8
Q

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

A

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.

9
Q

What advice should be given when stopping lithium treatment?

A

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.

10
Q

What are the patient/career advice for lithium?

A
  • 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

11
Q

What drugs increase the toxicity of lithium?

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

Metronidazole (MAY increase risk of toxicity)

12
Q

What drug increases risk of ventricular arrhythmias For lithium?

A

Amiodarone

13
Q

What drugs increase the risk of neurotoxicity of lithium?

A
Methyldopa
Phenytoin
Carbamazepine 
Diltiazem
Verapamil
14
Q

What is the target rage for carbamazepine?

A

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

15
Q

What are the monitoring requirements of carbamazepine?

A

FBC
Renal function
Liver function

16
Q

What are the warning signs of carbamazepine?

A

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.

17
Q

What is the major route of Elimination of carbamazepine?

A

Hepatic metabolism

Cyp450 enzyme inducer

18
Q

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

A
Vit D 
Consider in patients:
-who are immobilised for long periods 
-have inadequate sun exposure
-have inadequate dietary intake
19
Q

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

A

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

20
Q

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

A

Gradual withdrawal over at 4 weeks

21
Q

What are the patient/ career advice with carbamazepine?

A
  • report any warning signs to the doctor immediately
  • same brand all the time: (CATEGORY 1, like phenytoin, primidone, phenobarbital)
  • DVLA advice
22
Q

What drugs increase the levels of carbamazepine?

A
Cimetidine
Clarithromycin 
Erythromycin 
Isoniazid 
Fluoxetine
23
Q

What drugs decrease the levels of carbamazepine?

A

phenytoin
Rifabutin
St. John’s wort

24
Q

What drugs does carbamazepine reduce the levels of?

A
Antipsychotics 
Corticosteriods 
Coumarins
Eplerenone 
Oestrogens + progesterones 
Simvastatin
25
Q

What is the drug interaction between orlistat and carbamazepine?

A

Increased risk of convulsions

26
Q

What are the target ranges of ciclosporin?

A

Depends on clinical situation and indication for treatment.

27
Q

What are the monitoring requirements of ciclosporin?

A
  • 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

28
Q

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

A

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

29
Q

What ids the MHRA/CHM advice on ciclosporin

A

Patient should be kept on the same brand.

Switching can lead to clinically significant blood serum levels

30
Q

What are the warning signs of ciclosporin?

A
  • Neurotoxicity (tremor, headache, encephalopathy)
  • blood disorders
  • liver toxicity
  • nephrotoxicity (e.g. elevated serum creatinine concs)
  • vomiting, drowsiness, tachycardia
  • HTN
  • Headache
  • Gingivial hyperplasia.
31
Q

What are the patient/carer advice for ciclosporin?

A
  • 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.
32
Q

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

A

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

33
Q

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

A
  • Prolonged use increased suspectiblity to infections and severity of infections.
  • serious infections
34
Q

What is the target range for phenytoin?

A

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

35
Q

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

A

Interrupt enteral feeding for 2 hours BEFORE AND AFTER dose

36
Q

What are the signs and symptoms of phenytoin toxicity?

A

SNACHD

  • Slurred speech
  • Nystagmus
  • Ataxia
  • Confusion
  • Hyperglycaemia
  • Diplopia
37
Q

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

A

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

38
Q

What are the specific SEs with oral use of phenytoin?

A
  • Electrolyte imbalance
  • Vit D deficiency
  • pneumonicitis
39
Q

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

A

HEPATIC IMPAIRMENT

-Reduce dose to avoid toxicity

40
Q

How does azathioprine work?

A

It’s metabolised to mercaptopurine

41
Q

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

A

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

42
Q

What are the monitoring requirements of azathioprine?

A

-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

43
Q

What are the main SEs in azathioprine?

A
  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
44
Q

What are the dose requirements for elderly when taking azathioprine?

A

Reduce the dose in elderly

45
Q

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

A

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