Practice

Question 1

What drugs increase enzyme activity and reduce drug concentration?

Answer 1

• Phenytoin
• Carbamazepine
• Barbituates
• Rifampicin
• Alcohol (chronic excess)
• Sulphonylureas

Question 2

What drugs reduce enzyme activity and increase drug concentration?

Answer 2

• Allopurinol
• Omeprazole
• Disulfiram
• Erythromycin
• Valproate
• Isoniazide
• Ciprofloxacin
• Ethanol (acute intoxication)
• Suphonamides

Question 3

What medications need to be stopped before surgery?

Answer 3

I LACK OP
- Insulin
- Lithium
- Anticoagulants/antiplatelets
- COCP/HRT
- K-sparing diuretics
- Oral hypoglycaemics
- Perindopril and other ACEi

Question 4

How far in advance do medications need to be stopped before surgery?

Answer 4

• COCP/HRT - 4 weeks
• Lithium - day before
• K-sparing and ACEi - day of
• Anticoagulants/antiplatelets - variable (occasionally continued)
• Oral hypoglycaemic drugs - variable
• When NBM stop metformin otherwise lactic acidosis, can use a sliding scale.

Question 5

What drug can increase INR?

Answer 5

Erythromycin

Question 6

What are the side effects of steroids?

Answer 6

STEROIDS
- Stomach ulcers
- Thin skin
- oEdema
- Right and left HF
- Osteoporosis
- Infection e.g. candida
- Diabetes (hypoglycaemia, sometimes progresses to diabetes)
- cushing’s Syndrome

Question 7

What are the safety considerations of NSAIDs?

Answer 7

NSAIDs
- No urine i.e. renal failure
- Systolic dysfunction i.e. HF
- Asthma
- Indigestion (any cause)
- Dyscrasia (clotting abnormality)

Question 8

What are the side effects of antihypertensives?

Answer 8

• Hypotension i.e. postural
• Bradycardia - beta blockers, some CCBs
• Electrolyte disturbances with ACEi and diuretics
• ACEi - dry cough
• Beta blockers - wheeze in asthma, worsening of acute HF (help in chronic HF)
• CCBs - peripheral oedema and flushing
• Diuretics - renal failure
• Thiazide diuretics e.g. bendroflumethzide - gout
• K-sparing diuretics e.g. spironolactone - gynaecomastia

Question 9

What VTE prophylaxis is needed?

Answer 9

• The majority will receive LMWH e.g. dalteparin 5000 units OD SC and compression stockings.
• Patients with PAD (absent foot pulses) - no compression stockings

Question 10

Who should avoid metoclopramide?

Answer 10

• Young women
• Parkinson’s
  Due to dyskinesia i.e. unwanted movements, especially acute dystonia

Question 11

What anti-emetics are used?

Answer 11

• Cyclizine 50mg 8hrly IM/IV/oral - can cause fluid retention, can prescribe PRN
• Metoclopramide 10mg 8hrly IM/IV if HF
• Ondansetron 4mg or 8mg 8hrly IV/oral

Question 12

What is used in neuropathic pain?

Answer 12

Amitriptyline 10mg PO ON or pregabalin 75mg PO 12hrly

Question 13

What is used for pain in diabetic neuropathy?

Answer 13

Duloxetine 60mg PO OD

Question 14

What are the side effects of oxybutinin?

Answer 14

• Antimuscarinic drug used for urinary frequency and urgency
• Confusion, particularly in elderly
• Pupil dilation with loss of accommodation
• Dry mouth
• Tachycardia

Question 15

What could cause confusion in the elderly?

Answer 15

• Acute intracranial event
• Infection
• Electrolyte disturbance
• Urinary retention +/or constipation
• Opioids e.g. tramadol
• Cyclizine
• Benzodiazepines

Question 16

What are the contraindications for methotrexate?

Answer 16

• NSAIDs use with caution due to nephrotoxicity
• Infection
• Pregnancy
• Trimethoprim - increases bone marrow toxicity

Question 17

What is the maximum dose of paracetamol per day?

Answer 17

4g/day

Question 18

What route is insulin given?

Answer 18

Subcutaneous, except for sliding scale use IV short-acting insulin e.g. actrapid or novorapid

Question 19

What are the side effects of antipsychotics?

Answer 19

• Agranulocytosis - neutropenia
• Requires immediate cessation of drug and referral to haematologist

Question 20

What medications cause agranulocytosis?

Answer 20

• Antipsychotics
• Carbimazole
• Carbamazepine

Question 21

What are the causes of respiratory alkalosis?

Answer 21

Rapid breathing - disease or anxiety

Question 22

What are the causes of respiratory acidosis?

Answer 22

Same causes as T2RF ‘blue bloaters’

Question 23

What are the causes of metabolic alkalosis?

Answer 23

• Vomiting
• Diuretics
• Conn’s syndrome

Question 24

What are the causes of metabolic acidosis?

Answer 24

• Lactic acidosis
• DKA
• Renal failure
• Ethanol/methanol/ethylene glycol intoxication

Question 25

What are general rules of abx use?

Answer 25

• Flucloxacillin 1st for skin infections
• Metronidazole typically used for GI infections due to good effects on anaerobes that colonise the gut
• Clindamycin usually for bone infections

Question 26

What are the side effects of cyclizine?

Answer 26

• Acute closure glaucoma
• Dry mouth
• Dizzy (anti-muscarinic)

Question 27

What are the risks of tamoxifen?

Answer 27

• Increase risk of endometrial carcinoma
• Increase efficacy of warfarin - increase INR
• Increase risk of VTE

Question 28

What are the side effects of citalopram?

Answer 28

• Photosensitive - precautions should be taken in sunlight
• Dry mouth
• Serotonin syndrome: agitation, increased temp, hallucinations
• Can still have suicidal thoughts, seek help immediately. Can take up to 6 weeks to see improvement.

Question 29

What does phenytoin commonly interact with?

Answer 29

COCP - reduces efficacy. IUD are recommended instead if the patient is on OCP.