Side Effects and Interactions Flashcards
What are some common side effects of statins (like atorvastatin)?
ARTHRALGIA, MYALGIA, MYOSITIS, nausea and vomiting, flatulence, constipation, GI discomfort
What must you check before starting a patient on statins?
Lipid profile, triglyceride concentrations, liver function tests (LFTs), thyroid stimulating hormone (TSH) and renal function
What must you check during statin treatment, and how often?
LFTs repeated three monthly and at 12 months. If >3 times the upper limit of normal, stop atorvastatin therapy.
What is a concern in a patient taking statins who develops severe unexplained muscle pain (more than normal myalgia)?
Rhabdomyolysis
What drug do statins commonly interact withand what effect does this have?
Macrolide antibiotics like clarithromycin - macrolides inhibit CYP450 enzymes in the liver, increasing the exposure to statins. This can trigger rhabdomyolysis.
What are some common side effects of levothyroxine if given in excess?
Anxiety, restlessness, flushing, sweating, fine tremors, diarrhoea, nausea and vomiting
What monitoring is required for patients taking levothyroxine, and how often?
TFT every 3 months until stable, then once yearly
How can you manage the effects of excess levothyroxine?
Can reduce the dose
Can advise patients to take levothyroxine in the morning, 30 minutes before breakfast and drinks containing caffeine (absorption is reduced by food and caffeine)
What can levothyroxine interact with?
Antacids, calcium, and iron supplements can affect absorption of levothyroxine
What are some common side effects of PPIs like omeprazole?
Nausea & vomiting, stomach pain, constipation and flatulence
What are some long term risks of PPIs like omeprazole? (including electrolyte imbalances)
Increased risk of osteoporosis, Clostridium difficile infection, hypomagnesaemia and vitamin B12 deficiency
What are some common interactions with PPIs like omeprazole?
SSRIs - increases SSRI exposure as both are metabolised by the same enzyme
Clopidogrel - reduces it’s effectiveness as both are metabolised by the same enzyme (weirdly lansoprazole isn’t??)
Methotrexate - inhibits renal excretion of methotrexate so increases exposure
What are some common side effects of calcium channel blockers?
Dizziness, flushing, palpitations, headaches, peripheral oedema (leg swelling)
(You can work it out if you think about what might happen as a result of vasodilation)
What monitoring is required when patients take CCBs?
Regular blood pressure checks
It’s important to check that they don’t become too hypotensive if they’re on multiple anti-hypertensives
What can amlodipine interact with?
Simvastatin - both inhibit the same enzyme which increases simvastatin levels, and increases risk of rhabdomyolysis
What are the common side effects of ACE inhibitors like ramipril? (including electrolyte imbalances)
A dry cough due to bradykinin accumulation (change to ARBs!)
Hyperkalemia due to inhibition of aldosterone synthesis
Hypotension
What is a serious side effect of ACE inhibitors like ramipril and how should it be managed?
Angioedema - it can compromise the airway so ACE inhibitors should be stopped immediately
What should be monitored in a patient taking ACE inhibitors like ramipril?
Potassium levels
Why might ACE inhibitors be useful in people with renal diseases/diabetes?
They are renally protective - they can decrease proteinuria and slow the progression of diabetic nephropathy.
What can ACE inhibitors like ramipril interact with and what effect do they have?
NSAIDs - they reduce renal function and can exacerbate hyperkalaemia
What are some common side effects of BBs like bisoprolol?
Coldness of the peripheries, headaches, syncope, erectile dysfunction, dizziness and hypotension, NIGHTMARES
What condition are beta blockers contraindicated in?
Asthma - they can cause bronchospasm due to interactions with B2 receptors in the airway, leading to bronchoconstriction
What should BBs not be prescribed with, and what might the effect be if they are?
Non-dihydropyridine CCBs (verapamil, diltiazem) or amiodarone - might cause complete heart block
What are some common side effects of metformin?
Gastrointestinal and taste disturbances (metallic taste) are common when taking metformin. Metformin may cause B12 deficiency.
Weight loss
What are some common side effects of ADHD medications (like methyphenidate, dexamfetamine, atomoxetine)?
Small increase in BP, appetite loss (and subsequent weight loss), trouble sleeping, headaches, stomach aches, feelings of aggression or anxiety
What are is a serious side effect of atomoxetine for ADHD?
It might cause suicidal thoughts or liver damage
What monitoring is required for children on ADHD medications?
Height, weight, heart rate and blood pressure after every dose change, or every 6 months
What is a serious side effect of metformin and what are the symptoms?
Lactic acidosis - symptoms include abdominal pain, nausea, vomiting, shortness of breath and muscle cramps
What should be monitored before and during metformin treatment? How often?
Renal function - checked before starting then monitored yearly
It shouldn’t be used if eGFR <30
What can have serious interactions with metformin?
Intravenous contrast agents used in radiological investigations - both cause renal impairment and can increase the risk of lactic acidosis
(remember Dr Stan’s story in LICP1)
What are some common side effects of salbutamol? (including electrolyte imbalances)
Tachycardia, headaches and tremor due to coactivation of B1 receptors in the heart
Hypokalemia in high doses
Hypokalaemia is why it’s used to treat hyperkalaemia
What is a common side effect of inhaled corticosteroids for asthma and how can it be prevented?
Oral candidiasis can be prevented by rinsing your mouth out or brushing your teeth after using the inhaler
What is a common side effect of GTN spray?
Headaches (very common)
Feeling dizzy, weak, tired or sleepy
Feeling sick (nausea)
Red face (flushing)
Just think about what might occur as a result of vasodilation.
What are some side effects of bisphosphonates? (including electrolyte imbalances)
Hypocalcaemia, bone/joint pain, diarrhoea, fatigue, nausea and vomiting
What are some long term (but rare) effects of bisphosphonates?
Osteonecrosis of the jaw, atypical femoral fractures
What is a side effect of amitriptyline?
Feeling drowsy/sleepy is very common.
Also:
Constipation, dizziness, dry mouth, difficulty urinating, headache
What is a side effect of alpha blockers like tamsulosin?
Postural hypotension (so not prescribed in people with low blood pressure)
Retrograde ejaculation
What are some side effects of chemotherapy?
Alopecia, nausea, vomiting, fatigue, neutropenia, sexual dysfunction, increased infection susceptibility, anemia
Why is carbimazole contraindicated in pregnant women?
It’s teratogenic
What is a common side effect of carbimazole and PTU for hyperthyroidism? What are the symptoms?
Agranulocytosis
Manifests as a sore throat, fever, mouth ulcers
What are some side effects of systemic steroids?
Peripheral oedema in the legs
Hypertension
Problems with mood swings, memory, behavior, and other psychological effects, such as confusion or delirium.
Stomach disturbances
Weight gain in the abdomen, face and back of the neck
Proximal myopathy/weakness
Osteoporosis
What are some side effects of topical steroids?
Thinning of the skin which can make the skin more prone to tearing, bruising, stretch marks or flaring in future. Can also cause telaniectasia
What is a common side effect of sulphonylureas like gliclazide?
Hypoglycaemia
What is a rare side effect of SGLT2 inhibitors?
Necrotising fasciitis of the genitals (Fournier’s gangrene)
