High risk meds Flashcards
What are high risk drugs?
Medicines that can cause significant harm to the patient, may cause serious side effects especially when administered incorrectly or when dose is calculated incorrectly.
May have a narrow therapeutic range.
What is the half life of amiodarone?
About 50 days - loading doses may be required
Monitoring required for Amiodarone?
Thyroid function, liver function, serum potassium, chest x ray, ECG (with iv use)
Warning sings associated with amiodarone?
- Signs of hypothyroidism OR hyperthyroidism
- Corneal microdeposits
- Progressive SOB (pulmonary toxicity)
- Clinical signs of live disease
- Neurological effects of tremor, peripheral neuropathy
- Phototoxic skin reactions
Interactions with amiodarone?
Increased plasma concentrations with:
dabigatran, digoxin, flecainide, phenindione, phenytoin
Increased risk of arrhythmias with amisulpride. atomoxetine, chloroquine, citalopram, disopyramide, escitalopram, haloperidol, hydroxychloroquine, levofloxacin, lithium, mizolastine, melfoquine, moxifloxacin, phenothiazines, pimozide, quinine, sulpiride, tricyclics
Increased risk of bradycardia when given with beta blockers, dilitazem, verapamil
Increased risk of myopathy when given with simvastatin
What monitoring is needed with ACE inhibitors and ARB’s
BP, renal function and electrolytes
Warning signs with ace inhibitors and ARB’s?
Postural hypotension (dizziness, blurred vision)
Jaundice
Abnormal renal function
Water retention
Confusion, nausea, vomiting and dehydration (AKI)
Actions required for ACE inhibitors and ARBS:
- 1 in 10 people taking ACE inhibitor will get a dry cough, can take 8-12 weeks to disappear
- Routine bloods - 1-2 weeks after initiation and 1-2 weeks after dose changes
- Preferably give dose at bedtime
- Drink plenty of water
- Stop medication during sick days
ACE and ARB interactions?
- Can both increase concentration of lithium
- Can both increase potassium levels (hyperkalaemia)
- Increased risk of renal impairment when both give with aliskiren
Monitoring required for antipsychotics
FBC U+E's LFT's fasting blood glucose blood lipids BP Weight ECG
Warning sings for antipsychotics
Hyperthermia, muscle rigidity, fluctuating levels of consciousness, tachycardia, labile BP
Remember for clozapine: intestinal immobility, agranulocytosis, myocarditis and the risk of stopping smoking
Actions required for antipsychotics:
- Repeat ECG periodically and dose reduce if QT interval is prolonged
- Maintain adequate fluid intake
- Increase doses slowly
- Half doses used for elderly
- Avoid prescribing more than 1 antipsychotic
- Dont stop abruptly
- Photosensitisation risk in higher dose
Antipsychotic interactions:
- Increased hypotensive effect with ACE inhibitors, ARBs, CCB’s and B blockers
- Increased sedation with antihistamines and anxiolytics
- Increased risk of QT prolongation with amiodarone, citalopram, escitalopram, methadone and macrolide antibiotics
- Increased extrapyramidal side effects with metoclopramide and amantadine
What are extra pyramidal side effects:
Akathisia: Feeling restless like you can’t sit still
Dystonia: When your muscles contract involuntarily
Parkinsonism: Symptoms are similar to Parkinson’s disease
Tardive dyskinesia: Facial movements happen involuntarily.
Monitoring required for azathioprine
FBC, Renal Function, Liver function
Warning signs with Azathioprine?
- Signs of hypersensitivity i.e. fever,
- Hypotension
- N+V
- Unexplained bruising or bleeding
Actions required with azathioprine?
- if taking concurrent allopurinol, reduce dose to 1/4
- Measure TPMT before initiation
- Counsel patient to report any signs or symptoms of bone marrow suppression i.e. bruising, bleeding, infection
- Dose reduce in elderly
Interactions with azathioprine:
Increased risk of anaemia with ace inhibitors
Anticoagulant effect of coumarins reduced
Increased risk of haem toxicity with allopurinol
Increased risk of generalised infection which could be life threatening with live vaccines
What is the therapeutic range of carbamazapine?
4-12mg/l
Monitoring required for carbamazpine?
FBC, renal function, liver function
Warning sings for carbamazapine?
Toxicity –> blurred vision, drowsiness, arrythmias, N+V, diarrhoea, hyponatraemia
- Blood disorders - sore throat?
- Skin disorders - rash, sore throat?
- Hepatic disorders e.g. hepatitis
- Antiepileptic hypersensitivity syndrome
Actions required for carbamazepine?
- Advise to contact doctor about warning signs immediately
- Ensure that they receive the same brand each time
- Ensure patient is aware of the law surrounding seizures and driving
- Inform about potential interactions and need to check with a pharmacist or doctor before starting any other meds
Interactions with carbamazepine?
- Increased plasma conc with acetazolamide, cimetidine, clarithromycin, erythromycin, fluoxetine, isoniazid
- Decreased plasma conc with phenytoin, rifabutin, St Johns wort
- Carbamazepine reduced plasma conc of antipsychotics, corticosteroids, coumarins, eplerenone, oestrogens, progestogens, simvastatin
- Anticonvulsant effect antagonised by mefloquine, antipsychotics
- Possible increased risk of convulsions when antiepileptics given with orlistat
Common side effects of chemo
Extravasation of IV drugs = leakage N+V Bone marrow suppression (except vincristine and bleomycin) Fatigue Oral mucositis Hyperuricaemia Organ toxicities
Warning signs of neutropenic sepsis?
- Feeling unwell with two temp reading of 37.5 and above
- Shivering/flu like symptoms
- Uncontrolled bleeding/bruising
- Diarrhoea and/or uncontrolled vomiting
- Mouth ulcers
Actions required for chemo meds?
- Advise to visit a+e if development of signs of neutropenic sepsis and not to take paracetamol
- Report side effects immediately to doctor
- Pxing of anti emetics
- Advise to maintain good oral hygiene
Monitoring required for ciclosporin?
FBC, liver function, serum electrolytes, blood lipids, renal function, BP, dermatological and physical examination
Warning signs for ciclosporin?
- Neurotoxicity
- Blood disorders
- Liver toxicity
- Nephrotoxicity
- Hypertension
- Headache
- Gingival hyperplasia
Actions required for ciclosporin?
- Report any warning signs immediately
- Advise regular BP monitoring due to common side effect of hypertension
- Warn not to receive live vaccines
- Brand specific prescribing is recommended
- Avoid excessive sunlight exposure
- Avoid high potassium diet and grapefruit juice
Ciclosporin interactions
Increased plasma concentration with:
Clarithromycin, diltiazem, erythromycin, fluconazole, grapefruit juice, itraconazole, ketoconazole, miconazole, metoclopramide, verapamil, colchicine and tacrolimus
Decreased plasma conc with carbamazepine, orlistat, phenobarbital, phenytoin, rifampicin, st johns wort
Increased risk of hyperkalaemia when given with ACE/ARB inhibitors
Increased risk of nephrotoxicity when given with NSAIDs and increased plasma conc of diclofenac
Ciclosporin increases plasma conc of digoxin
Increased risk of myopathy when given with statins
Monitoring required for corticosteroids
BP, blood lipids, serum K+, body weight and height in children and adolescents, bone mineral density, blood glucose, eye exam, signs of adrenal suppression
Warning signs for corticosteroids?
- Bronchospasm
- Symptoms of uncontrolled asthma
- Frequent courses of abx/steroids
- Adrenal suppression
- Immunosuppression
- Psychiatric reactions e.g. nightmares
Actions required for corticosteroids?
- Report any warning signs to doctor immediately
- Give steroid card if treatment long term and warn them not to stop treatment abruptly
- Check if taking in the morning as a single dose
- Ensure rinsing of mouth after inhaled corticosteroids
- Advise to avoid anyone with chickenpox if they haven’t had it