Prescribing Flashcards
What are rules to remember when writing prescription charts?
- Must be legible + unambiguous
- Use an approved drug name w/ no abbrevations
- It must be written in capitals and signed
- If a drug is used ‘as required’, provide 2 instructions (indication and maximum freq/total dose in 24hrs)
- If Abx prescribed, include indication and stop/review date
PC BRAS
Enzyme inducers increase P450 activity, speeding up metabolism of other drugs with the result that they exert a reduced effect. Patient will require more of some other drugs in the presence of an enzyme inducer.
What are the enzyme inducers?
- Phenytoin
- Carbamazepine
- Barbiturates
- Rifampacin
- Alcohol (chronic)
- Sulphonylureas
Others = smoking, St John’s Wort
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Enzyme inhibitors reduce P450 activity. There will be an increased level of other drugs, so need to reduce their dose.
What are the enzyme inhibitors?
- Sodium valproate
- Isoniazid
- Cimetidine
- Ketoconazole
- Fluconazole
- Alcohol (acute) + grapefruit juice
- Ciprofloxacin
- Erythromycin
- Sulfonamides
- Chloramphenicol
- Omeprazole
- Metronidazole
- Allopurinol
Most drugs should be continued during surgery. Which drug should actually be increased?
Long-term corticosteroids
I LACK OP
What drugs should be stopped for surgery?
- Insulin - sliding scales to be given in all cases
- Lithium (day before)
- Anticoagulants/antiplatelets
- COCP/HRT (4 wks before)
- K-sparing diuretics (day of)
- Oral hypoglycaemics
- Perindopril + all other ACEi (day of)
What is used for rapid tranquilisation in acute agitated delirium psychosis?
- NICE suggest either IM Lorazepam on its own or IM Haloperidol combined w/ IM Promethazine
- Lorazepam 2mg IM
HYPOKALAEMIA
Plasma K+ of 3 mmol/L secondary to K+ loss represents a total deficit of around 300mmol. If possible, first treat the cause. Replacement can be by mouth or by IV infusion.
What is the oral replacement for hypokalaemia?
- First choice → Sando-K (12 mmol/tablet)
- Usual dose is 40-120 mmol/day
HYPOKALAEMIA
Who should IV replacement be reserved for?
- Symptoms of → paralysis / arrhythmia / hepatic enceph
- K+ < 2.5 mmol/L
- Intolerant of oral K+
What is the IV replacement for hypokalaemia and how much?
- Infuse K+ into large vein up to 10 mmol K+ / hour
- 20mmol potassium per ampoule are only available in intensive care areas and should not be used in ward areas unless in exceptional circumstances and under close supervision
- 20mmol KCI in 500ml sodium chloride 0.9% or glucose 5%
- 40mmol KCI in 500ml sodium chloride 0.9% or glucose 5%
- The rate of infusion should not normally exceed 10mmol/hour.
C. Diff infection Abx treatment
What is the treatment for a 1st episode of mild-mod infection?
Oral metronidazole
C. Diff infection Abx treatment
What is the treatment for a 2nd or subsequent episode of infection, for severe infection, for infection not responding to metronidazole, or if the patient is intolerant to metronidazole?
Oral vancomycin
What are the markers of severe C. Diff infection?
- WCC > 15 x 10
- Acutely rising creatinine (eg. > 50% increase)
- Temp > 38.5 C
- Evidence of severe colitis (abdo signs, radiology)
What is the stroke prevention in arrhythmia patients?
- Oral anticoagulation → warfarin sodium
When might a DOAC be used in arrhythmia stroke prevention?
If…
- Non-valvular AF
- Treatment of DVT/PE
- Prophylaxis of DVT/PE in elective hip/knee surgery
Which DOACs can be used for arrhythmia stroke prevention?
- Apixaban
- Dabigatran etexilate
- Edoxaban
- Rivaroxaban
