Clinical Check - Revision table for 322 OSCE PDF

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CLINICAL SCENARIOSScenario Issue Implication/ Clinical SignificanceSolutionsRx for furosemide (or any thiazide diuretic).PMR indicates that patient currently takes lithium.Risk of toxicity as excretion of lithium is reduced. Patient will experience GI s/e, visual disturbances, excessive urine, muscl...

Description

Rafchana Khanam

1131350402 CLINICAL SCENARIOS

Scenario

Issue

Rx for furosemide (or any thiazide diuretic).

Risk of toxicity as excretion of lithium is reduced. Patient will PMR indicates that patient currently takes experience GI s/e, visual disturbances, lithium. excessive urine, muscle weakness and tremor.

Implication/ Clinical Significance Lithium toxicity is made worse by sodium depletion therefore concurrent use with diuretics should be avoided.

Solutions 1. Withdraw treatment 2. Increased monitoring of lithium levels 3. Monitor renal function

Patient is wanting to buy an NSAID product.

Risk of toxicity as excretion of lithium is reduced. Patient will Their PMR indicates experience GI s/e, that they’re on lithium. visual disturbances, excessive urine, muscle weakness and tremor.

NSAIDs inhibit synthesis of renal prostaglandins (PGE2) therefore renal blood flow is reduced.

1. Avoid NSAID 2. Monitor serum lithium levels and reduce appropriately 3. Monitor renal function 4. Withdraw treatment if any signs of toxicity

Rx for lisinopril

Both ACE inhibitors and lithium cause sodium to be lost in the urine.

1. Monitor renal function

ACE inhibitors reduce excretion of lithium, PMR indicates patient thereby increasing is taking lithium lithium plasma concentrations. Patient may experience lithium toxicity. Rx for lithium liquid (li-liquid) 509mg/5ml, 5ml daily.

Oral liquid and tablets are not equivalent in dose.

PMR indicates patient Li-liquid 509 mg is was taking lithium equivalent to lithium carbonate 400mg carbonate 200 mg. tablets. Patient is finding difficulty swallowing tablets so has been prescribed liquid instead. 85-year-old patient Dose is too high for

ACEI also reduce thirst stimulation therefore fluid depletion can occur. Patient would be taking a lower dose i.e. sub therapeutic concentration.

1. Patient should take 10ml of the liquid daily to get an equivalent dose.

Prolongation of

1. Reduce dose 1

Rafchana Khanam comes into A&E with a myocardial infarction. SCR show that patient is on citalopram 40mg.

Rx for tramadol PMR shows patient is currently taking citalopram

patient; this causes prolongation of QT interval. Patient may experience nausea, vomiting, agitation, rapid eye movements, tremor, etc.

interval can cause syncope, cardiac arrest or sudden death.

Concurrent use of tramadol and an SSRI can cause an increased risk of seizures and serotonin syndrome.

Serotonin syndrome can be fatal.

Patient may experience tremors, restlessness, fever, confusion, visual disturbances, etc. Patient is wanting to buy ibuprofen but is currently taking citalopram.

Increased risk of GI bleeding.

Patient’s blood test reveals hyponatremia (low sodium levels).

Citalopram causes hyponatremia due to inappropriate secretion of antidiuretic hormone

PMR indicates the patient currently takes citalopram.

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Increased risk of hyponatremia.

to a maximum of 20mg.

Tramadol can induce seizures whereas SSRIs can reduce seizure threshold therefore the risk is increased.

1. Ask the prescriber what the tramadol is being taken for; change to an alternative e.g. codeine or morphine.

Can cause lethargy, confusion, seizures, and, in some cases, death.

1. Paracetamol should be offered as an alternative.

Can cause lethargy, confusion, seizures, and, in some cases, death.

1. Gradually reduce citalopram dose while starting mirtazapine i.e. cross tapering.

2

Rafchana Khanam Patient is currently on azathioprine.

Bone marrow suppression.

Patient will easily bruise and bleed. Will have fever and rashes.

Blood test show low levels of WBC and platelets.

Patient is currently on azathioprine.

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Infection

1. Stop azathioprine and refer to haematologist. Continue to monitor blood levels.

Blood test show high levels of WBC.

Rx for co-trimoxazole/ Increased risk of trimethoprim haematological toxicity. PMR indicates that patient currently takes Bone marrow azathioprine. suppression.

1. Depends upon indication of antibiotic: - Chest infection: amoxicillin - UTI: nitrofurantoi n

Patient taking azathioprine begins having unexplained nose bleeds.

Blood disorder/bone marrow suppression

Rx for azathioprine.

Azathioprine Increased risk of decreases the bleeding; could be anticoagulant effect of fatal. warfarin.

PMR indicates the patient is on warfarin.

1. Stop azathioprine and refer to haematologist. Continue to monitor blood levels.

Risk of anaemia, fatigue, infection and bleeding.

1. Stop azathioprine and report to GP immediately

1. Increase dose of warfarin and monitor 2. Refer to specialist/warf arin clinic.

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Rafchana Khanam

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Increased risk of heart failure

Can be fatal

1. Stop diclofenac – offer paracetamol as an alternative

Prolongation of QT interval, indicating myocardial electrical instability.

Could be fatal

Breakthrough dose calculation

Ensure the breakthrough dose is 1/10th to 1/6th of the total 24-hour dose.

If the dose is too high, it can cause fatal side effects such as respiratory depression.

1. Stop medication and refer to consultant 2. Further monitoring required 3. Clozapine given as an alternative. 1. Calculate appropriately and ensure the right strength is given

Rx for epanutin 30mg/5ml, 50ml daily.

Not bioequivalent dose: 100 mg = 92 mg

Phenytoin has a narrow therapeutic index therefore can have a large effect on seizure incidence and s/e.

Rx for diclofenac. Patient has a history of CV problems e.g. MI or HPT

Patient on olanzapine. Is brought into hospital with an abnormal ECG.

Patient previously on phenytoin 300mg capsule but has switched to liquid formulation due to struggle swallowing.

Rx for: Phenytoin 100mg capsules (actavis): 2 OD Levetiracetam 500mg tablets (actavis): 1 BD Patient PMR

Phenytoin should be maintained on a specific brand however it this case, it is for the patients benefit.

Phenytoin should remain on the same brand. Levetiracetam does not have to remain on the same brand although it is

1. Equivalent dose will be 46ml 100 mg = 92 mg 300mg = 276 mg 30mg = 5 ml 276 mg = 46 ml

Phenytoin has a narrow therapeutic index. Different brands do not have the same bioavailability. Changing brand increased the risk of

1. Should remain on same brand; ask prescriber the reason for the change.

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Rafchana Khanam

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indicates: Phenytoin 100mg (teva): 2OD Levetiracetam 500mg (zentiva): 1OD

recommended.

Rx for citalopram 40mg. Patient is 75 years old. Blood tests reveal they have low sodium levels.

Maximum dose of Hyponatraemia can citalopram in over 65s cause drowsiness, is 20mg. confusion and convulsions.

Junior doctor wants to prescribe ibuprofen and tramadol for postoperative pain.

Combination of SSRI and tramadol can increase the risk of seizures and serotonin syndrome – tramadol also inhibits the re-uptake of serotonin.

Patient is currently on citalopram 40mg.

Combination of SSRI and NSAIDs can increase risk of GI bleed. Patient has been taking fluoxetine 20mg for two weeks. She reports feeling ‘terrible’, ‘nauseous’ and her mood has not improved. She asks if she can stop taking them.

Treatment should be continued for four weeks before considering whether to switch to an alternative antidepressant.

seizures and adverse side effects.

1. Withdraw SSRI and monitor sodium levels.

Serotonin syndrome can cause changes in mental status, autonomic hyperactivity (e.g. tachycardia, diarrhoea) and neuromuscular abnormalities (hyperreflexia)

1. Do not use SSRI and tramadol in combination; offer alternative. 2. NSAID can be used if it is for short term therapy; consider use of PPI if to is for long term.

Adverse effects are common at the start of therapy.

1. Patient should be referred back to their GP; the first few weeks of therapy are challenging therefore they should be supported by regular GP reviews. 2. Patient should be made aware that it takes two to four weeks for antidepressant to take effect.

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Rafchana Khanam

Patient has been on paroxetine for three years. He feels he is ready to stop therapy and has told his GP that he intends to stop next week.

There is a risk of withdrawal symptom if antidepressant is stopped suddenly after regular administration of eight weeks of more.

Withdrawal effects are usually mild and self-limiting e.g. N&V, headaches, etc. Can be more severe.

TCA are not first line for depression. Patient may have been prescribed TCAs if other treatment options have failed.

Large quantity: should not be given because CV and epileptogenic effects are dangerous in overdose – over dose of amitriptyline has a high fatality rate.

How should the GP respond?

Rx for amitriptyline 100mg tablets, 1ON (112) Is this clinically appropriate?

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Drugs with a shorter half-life e.g. paroxetine and venlafaxine, are associated with higher risk of withdrawal symptoms.

Does the patient have CVDs e.g. previous TCAs are extremely MI, angina, etc.? cardio toxic in overdose and pose a Does the patient have higher risk in those hyperthyroidism? with CVD. Does the patient have Thyroid hormones are epilepsy or diabetes? also cardio toxic therefore take care in those patients. TCAs have antimuscarinic activity therefore antimuscarinic s/e.

1. Dose should be reduced gradually over four weeks or longer if withdrawal symptoms emerge – six months in patients who have been on long term maintenance treatment. 1. Ensure the patient is stable on this dose 2. Ensure the patient has tried other first line treatments 3. Reduce the quantity 4. Ensure the patient does not have CVD, HTD, epilepsy or diabetes, 5. Inform them of the s/e e.g. constipation, dry mouth, blurred vision and urinary retention.

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Rafchana Khanam Rx for amitriptyline 10mg, 1ON (28) What is the likely indication?

Patient presents with symptoms of a tremor and rhythmical involuntary movements of tongue and face. PMR shows:

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Low dose amitriptyline is most likely for neuropathic pain

Unlicensed but commonly used in pain management

1. Confirm the indication – this would be a very low dose if the indication was depression.

First generation antipsychotics (e.g. chlorpromazine, haloperidol) can induce extrapyramidal s/e. Usually develop on long term or high dose therapy.

May be irreversible on withdrawing therapy and treatment is usually ineffective, Some manufacturers suggest drug withdrawal at the earliest sign of tardative dyskinesia.

1. Some EPSE can be supressed by procyclidine but this is not routinely used as it can worsen the symptoms. 2. Give olanzapine as an alternative – it is a second generation antipsychotic.

Second generation antipsychotics are less likely to cause EPSE but can cause hyperglycaemia

This can lead to diabetes

1. Continue monitoring bloods more regularly.

Chlorpromazine 75mg TDS Paracetamol 500mg 2 QDS

Patient has been on olanzapine for two years. Routine blood test shows a raised fasting blood sugar level. Why?

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