PSA Flashcards
Enzyme inducers
[Decrease drug] PCBRATS
- Phenytoin
- Carbamazepine
- Barbituates
- Rifampicin
- Alcohol chronic
- Toprimate
- Sulphonylureas (stimulates pancreatic insulin secretion)
COCP affected by these
Enzyme inhibitors
[Increase drug] AODEVICES
- Allopurinol
- Omeprazole
- Disulfiram (adjunct in alcohol dependence treatment)
- Erythromycin
- Valproate
- Isoniazid
- Ciprofloxacin
- Ethanol acute
- Sulphonamides (abs)/ Sertraline
- Grapefruit & Ketoconazole
Medication to stop before surgery
I LACK OP
- Insulin: continue long acting at lower dose. Stop short acting until E&D. Variable rate needed in theatre
- Lithium: Day before
- Anticoagulants/ Antiplatelets
- COCP/HRT: 4 weeks before
- K sparing/ ACEi: Day of
- Oral hypoglycaemic
- Perindopril
a) Metformin SE in context of surgery
b) When is metformin contraindicated?
a) Lactic acidosis particularly in renal failure
b) Significant renal impairment or acutely unwell
SGLT 2 inhibitors SE in context of surgery
DKA
Drugs/Conditions causing hyperkalemia
- ACEi
- Potassium sparing
- Deltaparin
DREAD
- Drugs
- Renal failure
- Endocrine (Addison’s)
- Artefact (clot)
- DKA
Drugs/ Conditions causing HYPOkaleamia
- Thiazides
- Loop diuretics
DIRE
- Drugs
- Inadequate intake
- RTA
- Endocrine (Cushing’s/ Conn’s- hyperaldosternism on principle cells causing K+ out and Na+ in
Drug class causing gynaecomastia
Potassium sparing
Drug class causing gout
Thiazide diuretics
What antiemetic should you avoid in PD and young women
Metoclopramide due to dyskinesia
What DMARD should be withheld in active infection
Methotrexate
Drugs causing low neutrophils
Clozapine & Carbimazole
Digoxin toxicity
Confusion, Nausea, Visual halos, Arrythmia
Lithium toxicity
Early: Tremor
Intermediate: Tiredness
Late: Arrhythmia (T wave inversion/ flatten), Seizure, Coma, Renal failure, DI
Precipitated by: Dehydration; Renal failure; Diuretics (especially thiazides), ACE inhibitors/angiotensin II receptor blockers, NSAIDs and metronidazole.
Measure levels 12hrs after dose
Monitor:
Before: BMI, U&E, FBC
Every 6m: BMI, U&E & eGF (Renal function), Thyroid
Phenytoin toxicity
- Gum hypertrophy
- Ataxia
- Nystagmus
- Peripheral neuropathy
- Teratrogenicity
- Hepatotoxicity
Monitoring trough levels just before dose if: dose change, toxicity, non-adherence
In epilepsy: Fluroquinolones worsen it
Gentamicin and Vancomycin toxicity
Ototoxicity & Nephrotoxicity
INR deranged what do you do?
Major bleed: Stop warfarin, Give Bit K 5-10mg IV, Give PT
Common side effects of Lamotrigine
- Rash
- (SJS)
Common side effects of Carbamazepine
- Rash
- Dysarthria
- Ataxia
- Nystagmus
- Low sodium
Sodium valproate SE
Tremor
Teratogenic
Weight gain
Levetiracetam
Fatigue
Mood disorder
Agitation
What is 1%
1g in 100mL or 10mg in 1mL
What is the monitoring for statins
- Before: Lipids including triglycerides, TSH, U&E, LFT, CK in patients who have muscle pain, HbA1c for DM
- During: LFT 3m &12m for signs of hepatotoxicity, HbA1c 3m
Monitoring requirement is usually about LFT you need this!
What must you check before prescribing vancomycin?
CK levels, clearance reduced in renal failure
SE of Heparin
Haemorrhage & HIT
Side effect of statins
Myalgia, Rhabdomyolysis
SE of Amiodarone
ILD (pulmonary fibrosis), Thyroid disease, Skin greying, Corneal deposits
Causes of low sodium
- Fluid loss
- Diuretics (all)
- Addison’s
- SSRI
- SIADH
- Carbamazepine → SIADH
- Renal
- Heart failure
- Sulfonylureas
Drugs contraindicated in asthmatics
NSAIDS, Beta blockers
Drugs affected by CYP
- Statins
- Warfarin
- COCP
Methotrexate monitoring requirements
FBC, U&E, LFT ever 1-2w until stabilised then 2-3m.
Monitor for signs of infection
Asthmatic patient in AF what do you give?
CCB with rate control eg: Diltiazem/ Verapamil
Do NOT give: NSAIDs, Beta Blocker or Adenosine
Hyperkalaemia, First drug to lower potassium
10 units of a short-acting insulin (e.g. ACTRAPID) alongside dextrose (e.g. 50 ml 50% or 100 ml 20%) over 30 minutes.
Plasma potassium should be checked 30 minutes following the infusion via a venous blood gas and formal U&Es checked 1-2 hours later.
What would stop you using metformin first line
- Under/normal weight patient
- Creatinine of >150 mmol/L
Drugs that commonly cause urinary retention
Opioids
Anticholinergics
Anaesthetics
Alpha 1 agonist
BDZ
NSAID
CCB
Antihistamines
Gentamicin dosing
Major determinant is the concentration POST dose
- if the trough (pre-dose) level is high the interval between the doses should be increased
- if the peak (post-dose) level is high the dose should be decreased
Medicine contraindicated in HF
- thiazolidinediones
- pioglitazone is contraindicated as it causes fluid retention
- verapamil
- negative inotropic effect
- NSAIDs/glucocorticoids
- should be used with caution as they cause fluid retention
- low-dose aspirin is an exception - many patients will have coexistent cardiovascular disease and the benefits of taking aspirin easily outweigh the risks
- class I antiarrhythmics
- flecainide (negative inotropic and proarrhythmic effect)
Drugs usually prescribed weekly
Methotrexate
Alendronic acid
When do you need to do gradual withdrawal of corticosteroids?
- >40mg/day for 1 week
- >3w of treatment
- Recently received repeated courses
Potentiated warfarin
- Liver disease
- CYP450 enzyme inhibitors
- Cranberry juice
- NSAIDs
Avoid in breastfeeding
What may worsen seizure control in epilepsy?
- Alcohol, Cocaine, Amphetamines
- Ciprofloxacin, Levo
- Aminophylline, Theo
- Bupropion
- Methylphenidate
- Mefanamic acid
ACE inhibitors
- Small rise in creatinine <20% expected and ok, do not need to change prescription
