OSCE: Drug Counselling

Question 1

Describe how to take lithium

Answer 1

Lithium is prescribed in both tablet and liquid form. It is likely you’ll be told the form and dosing regimen the patient has been prescribed in the brief.
- Inform the patient to swallow the medication with plenty of water
- The patient can choose when to take it, but you must encourage them to take the medication at the same time every day.
- Inform the patient that they should not stop taking lithium suddenly or change their dose without speaking to their doctor first.
- If a patient misses a dose of lithium, inform them not to take a double dose and instead to take their next dose as normal
- Mention that patients on lithium will receive a lithium record book.1 They should take this book to all of their appointments to help keep track of their blood test results

Question 3

Describe how you would discuss monitoring lithium?

Answer 3

Lithium may take several weeks or months to begin working. Explain to the patient that it takes several weeks to get the dose of lithium correct
- To do this we will need to take a blood sample every week at the beginning of your treatment
- The lithium level must always be measured 12 hours after their previous dose
- Once the lithium level is stable the frequency of blood tests will decrease to once a month, and finally once every 3 months.2

Question 4

Which other tests would you need to have for lithium medication? [1]

Answer 4

In addition, the patient will require six-monthly thyroid function tests, urea and electrolytes and calcium monitoring.2

Question 5

What are the side effects of lithium? [7]

Answer 5

Use the mnemonic LITHIUM to remember the side effects and complications:

Lethargy
Insipidus (diabetes)
Tremor
Hypothyroidism
Insides (gastrointestinal)
Urine (increased)
Metallic taste

Question 6

Describe the risks of lithium in pregnancy [+]

Answer 6

Lithium associated birth defects generally occur within the first trimester of pregnancy when the fetal organs are developing
* Lithium has been shown to increase the risk of fetal heart defects
* Lithium is able to pass into the baby’s circulation through breastmilk and breastfeeding should therefore be avoided

Advise the patient that they should use a reliable method of contraception such as a subdermal implant or intrauterine system (IUS) to prevent accidental pregnancy whilst taking lithium.

Question 7

What are withdrawal symptoms like for antidepressants? [3]

Answer 7

Flu-like symptoms, dizziness and mood changes

Question 8

You prescribe a patient an SSRI.

What information would you give them about potential side effects? [5]

Answer 8

Risk of GI upset, changes in appetite and weight (loss or gain)

Confusion and reduced conciousness (due to hyponatraemia)

Suicidal thoughts and behaviour

Lower seizure threshold

Citalopram: prolongs QT interval

In combination with other serotnergic drugs - serotonin syndrome (autonomic hyperactivity, altered mental state and neuromuscular excitation)

Question 9

Which drugs should patients on SSRIs not be given with? [3]
- Explain why [+]

Answer 9

MOA inhibitors and other serotonergic drugs (e.g. tramadol) due to risk of SS

Bleeding has increased risk with NSAIDs, aspirin, anticoagulants

Drugs that prolong QT interval (e.g. antipsychotics)

Question 10

How long do you withdraw SSRIs for? [1]
Except which drug and how long is this for? [1]

Answer 10

4 weeks except fluoxetine, which is 2 weeks

Question 11

You prescribe a patient an SNRI.

What information would you give them about potential side effects? [5]

Answer 11

GI upset

Dry mouth

Neurological effects (headache, abnormal dreams, insomnia, confusion, convulsions)

Suicidal thoughts and behaviour

Hypertension

Question 12

Which side effect is mirtazepine particularly associated with? [1]

Answer 12

Bone marrow suppression

Question 13

Which population should venlafaxine be avoided / used in caution with? [1]

Answer 13

People at risk of arrythmia - due to ischaemic heart disease

Question 14

What would you need to consider with regards to number of prescriptions given out for SSRIs? [1]

Answer 14

If hx of overdose, need to limit them

Question 15

What would contraindicate SSRI use? [2]

Answer 15

Hx current recreational drugs - cocaine, ecstasy, LSD due to risk of SS

Caution with patients with mania

Question 16

Describe how you would explain how an SSRI works [2]

Answer 16

Block the uptake of serotonin in brain - more serotonin to be available for longer

Seratonin impacts emotions and sleep. Also helps biological symptoms such as low energy

Will feel slight benefit after 1/2 weeks but generally up to 6 weeks for full effect

Question 17

Describe how you take an SSRI [3]

Answer 17

Once a day dose

If miss a dose, take as soon as remember, unless the next dose is due. If so, omit previous and take normal as per

Don’t stop abrupty - risk of discontin. syndrome:
- Flu like syndrome
- Electric shocks
- GI upset
- Anxiety
- Dizziness

Question 18

How do you monitor SSRI use? [2]

Answer 18

Follow up a week if young
Follow up again at 4-6 weeks

Question 19

Which symptoms would you safety net a patient with for SS? [4]

Answer 19

If you experience severe diarrhoea, racing heartbeat, feel sweaty and shivery, muscle twitches or confusion: seek medical attention

Question 20

What lifestyle advise do you need to give patients with SSRIs? [+]

Answer 20

can make them dizzy, drowsy, or blurred vision.
- alcohol can exacerbate side effects such as drowsiness

Make people more vulnerable to heat stroke or exhaustion - be aware for exercsing

Question 21

Describe how you would tell someone to take clozapine

Answer 21

Clozapine is prescribed at a low dose to start off with and this is titrated up over a period of several weeks. It is important that doses are not missed. This is because if clozapine is not taken for more than 48 hours the titration process needs to start again.

Question 22

What are the advantages / disadvantages of clozapine?

Answer 22

Advantages:
- Studies have shown that approximately six out of ten people with treatment-resistant schizophrenia will benefit from taking clozapine.
- There is also research that demonstrated clozapine is superior to olanzapine when preventing suicide attempts in patients with schizophrenia and schizoaffective disorder

Side effects (Common):
Sedation: may improve with time but can consider night-time dosing only
Constipation: bowel monitoring, high fibre diet advice and stimulant laxatives
Tachycardia: consider cardiology advice as persistent tachycardia could represent a cardiac complication, otherwise beta-blockers can be used
Weight gain: dietary advice is important, metformin has also been shown to be effective for treating clozapine-induced weight gain
Hypersalivation: often improves over time, if troublesome for the patient hyoscine can be used

Rare, but serious side effects:
- Agranulocyotosis
- Myocarditis
- Ileus and bowel obstruction

Question 23

Describe how you monitor clozapine [+]

Answer 23

During the first 18 weeks of administration, patients are required to have their full blood count checked weekly.

This changes to fortnightly after 18 weeks and then monthly after one year

All patients in the United Kingdom taking clozapine will be registered with the service that manufactures their type of treatment and medication will only be dispensed if blood tests are within acceptable limits.

Question 24

What can change the effect of clozapine? [1]

Answer 24

Levels of clozapine can rise significantly with the reduction and cessation of cigarette smoking.

Question 26

Describe how you would describe MTX use [1]

Answer 26

“Methotrexate is a medication that can be used to decrease inflammation. Using this medication will help to reduce the symptoms associated with rheumatoid arthritis, especially joint pain, swelling and stiffness.”

Question 27

Describe how you would tell someone to take MTX

Answer 27

Methotrexate tablets are **prescribed as a once-weekly dose** and are **taken on the same day**each week - It is good practice to decide with the patient which day of the week they will take their dose and **write this down in full on the prescription** **Folic acid** should be co-prescribed with **methotrexate**. It can be taken **once weekly on the day** after the methotrexate dose, or it can be **taken once daily every day except on the day of the methotrexate dose** - Folic acid reduces the side effects of methotrexate. It can decrease mucosal and gastrointestinal side effects and may prevent liver toxicity.6 Starting doses may vary for different conditions. For example, the starting dose for **rheumatoid** **arthritis** is **7.5mg** whereas psoriasis is anywhere between 2.5 mg and 10 mg.

Question 28

What do you need to warn about MTX OD? [1]

Answer 28

Patients and carers should be i**nformed of the potentially fatal risk of overdose if methotrexate** is taken more frequently than once a week, and emphasise that it **should never be taken daily**. If an overdose does occur, **immediate medical attention** must be sought.6

Question 29

What are missed pill rules for MTX? [1]

Answer 29

Advise the **patient that if they forget to take a dose**, to take it as **soon as they remember the next day or the day after**. If the dose is **more than two days late,** they must **contact their GP or clinic** for advice. Patients should be advised to never take two doses together to make up for a missed dose.1

Question 30

Side effects of MTX?

Answer 30

**Common side effects of methotrexate include** * Loss of appetite * Nausea * Indigestion * Diarrhoea * Headaches * Tiredness * Hair loss **Rare but serious side effects of methotrexate include** * Liver toxicity: jaundice * Pulmonary toxicity: persistent cough, chest pain, dyspnoea * Renal toxicity: peripheral oedema, polyuria * Signs of infection: fever, chills, muscle aches, sore throat * Thrombocytopenia: bleeding gums, haematuria, unexplained bruising * Stevens-Johnson syndrome: severe skin rash or blisters on skin, mouth, eyes or genitals

Question 31

Which drugs would you advise shouldn't take with MTX? [2]

Answer 31

When **NSAIDs** (e.g. ibuprofen) are taken with **methotrexate** there is an **increased risk of toxicity.** **Trimethoprim or co-trimoxazole** (septrin) co-prescribed with methotrexate can be fatal. This is due to an additive effect of inhibiting dihydrofolate reductase, which increases the risk of bone marrow suppression. This can occur even with short courses and low doses, therefore these drugs must never be co-prescribed.

Question 32

How would you advise MTX monitoring?

Answer 32

**When beginning treatment, full blood count, renal and liver function tests** should be carried out every **1-2 weeks until the therapy is stabilised**. **Thereafter, patients should be monitored every 2-3 months**.3 In addition, testing for **viral hepatitis and tuberculosis** before starting methotrexate may be required. These results are required before commencing further treatment options should methotrexate be ineffective.

Question 33

What need to check with a patient if starting MTX? [1]

Answer 33

Methotrexate is contraindicated in pregnancy and breastfeeding due to its risk of teratogenicity. This point should be emphasised to any young, female patients being counselled about methotrexate.3