PSA revision Flashcards
what are the most common enzyme activity inducers?
PC BRAS:
Phenytoin Carbamazepine Barbiturates Rifampicin Alcohol (in chronic XS) Sulphonylureas
What do enzyme inducers cause in terms of drug concentration?
decrease drug concentration
How do enzyme inducers cause changes to drug concentration?
They cause cytochrome P450 to increase its activity, increasing drug metabolism - this breaks down the drugs faster reducing their activity
what are the common enzyme activity inhibitors?
A-O DEVICES
Allopurinol Omeprazole Disulfiram Erythromycin Valproate Isoniazid Ciprofloxacin Ethanol (acute ingestion) Sulphonamides
What drugs should NEVER be stopped before surgery?
calcium channel blockers
B Blockers
What drugs should be increased for surgery?
Corticosteroids in patients with long term CS use.
Follow ‘sick-day’ rules of doubling dose at anaesthesia
What drugs should be stopped before surgery?
I LACK OP
Insulin
Lithium
Anticoagulants/antiplatelets
COCP/HRT
K - sparing diuretics
Oral hypoglycemics (Metformin, Sulfonylureas) Perindopril + other ACEi
When should you stop HRT/COCP before surgery?
4 weeks before
When should you stop lithium before surgery?
day before
When should you stop K sparing diuretics before surgery?
day of surgery
When should you stop ACEi before surgery?
day of surgery
what is the PReSCRIBER pneumonic?
Patient details Reaction / allergies Sign the front of the chart Contraindications for each drug Route of each drug IV fluids - prescribe Blood clot prophylaxis - prescribe antiEmetics - prescribe pain Relief - prescribe
what two commonly used drug names contain penicillin?
co-amoxicav and tazocin
what are the 4 important drug classes to know contraindications for?
- antiplatelets and anticoagulants
- steroids
- NSAIDS inc. asprin
- antihypertensives
when are anti-platelets and anticoagulants CI?
when patients is suspected of bleeding
patient at risk of bleeding:
- prolonged PPT / liver disease
a patient has had an acute ischaemic stroke which drug should not be prescribed
profylactic heparin
a patient is prescribed a new drug. Their DHx includes warfarin.
After this new drug was prescribed their INR began to increase
what drug was likely prescribed?
erythromycin
increases PPT and so increases INR
what side effects are associated with steroids?
STEROIDS
Stomach ulcers Thin skin oEdema R + L heart failure Osteoporosis Infections including candida Diabetes - hyperglycaemia occurring more commonly than full flown diabetes Syndrome (cushings)
when are NSAIDS contraindicated
NSAID
No urine (renal failure) Systolic dysfunction (ie heart failure) Asthma Indigestion + reflux Dyscrasia of clotting (clotting abnormality)
How might hypotension occur with BB or some CCB
bradycardia
how might hypotension occur with ACE-i or diuretics
electrolyte disturbances
a patient has hypertension they are prescribed a drug to manage this.
Shortly after starting this new drug they develop a dry cough.
What drug was likely prescribed?
ACEi
a patient has hypertension they are prescribed a drug to manage this.
They have asthma. What drug is C/I and why?
Beta blocker
causes wheeze in asthmatics
in which type of heart failure are B Blockers C/I
acute - worsen Sx
but useful in chronic
a patient has hypertension they are prescribed a drug to manage this.
Shortly after starting this new drug they develop red skin - not sore only slightly warm.
What drug was likely prescribed?
CCB - causes skin flushing
a patient has hypertension they are prescribed a drug to manage this.
Shortly after starting this new drug they develop a peripheral oedema.
What drug was likely prescribed?
CCB
a patient has hypertension they are prescribed a drug to manage this.
Shortly after starting this new drug they develop severely painful and swollen toe joint.
What drug was likely prescribed?
Thiazide like diuretic - causes gout
a patient has hypertension they are prescribed a drug to manage this.
Shortly after starting this new drug they develop gynaecomastia.
What drug was likely prescribed?
spironolactone (k sparing diuretics)
a patient has hypertension they are prescribed a drug to manage this.
Shortly after starting this new drug they develop anuria.
What drug was likely prescribed?
diuretics - can cause renal failure
