Nota Perubatan

Category: Medications

  • Furosemide

    Adverse Effects

    Ototoxicity

    Illustrated example: “A 58-year-old male with underlying HFrEF and chronic kidney disease stage 4, presented with acute decompensated CCF. He was started with IV furosemide for rapid diuresis. On day 3 of admission, he complained of decline in hearing, with on and off tinnitus.”

    Furosemide is a commonly used medication in patients with fluid overload. However it can lead to ototoxicity especially in:
    ⛽️ Very high dose of furosemide (e.g. IV Furosemide >240 mg/hour)
    ⛽️ Lower doses of furosemide (e.g. IV Furosemide 80 – 160 mg/hour) but concurrent use of other ototoxins such as aminoglycosides (e.g. gentamicin, amikacin) OR with impaired kidney functions (i.e. AKI / CKD)

    The hearing disorder can be transient / permanent

    Mechanisms of ototoxicity
    ⛽️ Furosemide interferes with the ion transport mechanisms in the cochlea, particularly affecting the stria vascularis, which is responsible for maintaining the ionic balance necessary for hearing

    Other adverse effects of furosemide

    ⛽️ Hyponatraemia
    ⛽️ Hypokalaemia
    ⛽️ Hypotension
    ⛽️ Hyperuricaemia
    ⛽️ Metabolic alkalosis

    Hence, we should be more aware if the patients in the ward reporting hearing disturbances while on furosemide treatment. Reduce the dose of furosemide if higher doses are not necessary.

    Miscellaneous

    • Furosemide (Lasix®) vial: 10 mg/mL. Example: IVI Lasix 0.5 mL/hr = 5 mg/hr = 120 mg/day = 40 mg TDS
    • Furosemide 40 mg is equivalent to bumetanide 1 mg. At higher bumetanide doses, this ratio falls. Bumetanide is usually used only if the patient is unresponsive to furosemide.

    References / Further Readings

    1. Loop diuretics: Dosing and major side effects (https://www.uptodate.com/contents/loop-diuretics-dosing-and-major-side-effects)

    Keywords: frusemide, lasix

  • Medications – Generic Names & Brand Names

    Generic NameBrand Name

    Ampicillin / Sulbactam

    Unasyn

    Apixaban

    Eliquis

    Cefoperazone

    Cefobid

    Ceftazidime

    Fortum

    Ceftriaxone

    Rocephine

    Co-amoxiclav

    Augmentin

    DIazepam

    Valium

    Levetiracetam

    Keppra

    Rivaroxaban

    Xarelto

    Sodium valproate

    Epilim

  • Cephalosporin

    First Generation

    • Cefazolin
    • Cefalexin

    Second Generation

    • Cefuroxime
    • Cefoxitin

    Third Generation

    • Cefoperazone (Cefobid)
    • Ceftazidime (Fortum)
    • Ceftriaxone (Rocephine)

    Fourth Generation

    • Cefepime

    Fifth Generation

    • Ceftaroline

  • Corticosteroids

    Examples

    • Prednisolone
    • Hydrocortisone
    • Dexamethasone

    Miscellaneous

  • Noradrenaline

    Miscellaneous

    • IVI Noradrenaline
      • Should be administered via large peripheral veins (e.g. antecubital fossa)
      • Use at least green branula
      • If IVI Noradrenaline is to be given >6 hours, it’s advisable to give administer IVI Noradrenaline via CVL

  • Vancomycin

    Miscellaneous

  • Insulin

    Insulin injection Technique

    http://www.myhealth.gov.my/en/insulin-injection-technique/

  • N-Acetylcysteine (NAC)

    Introduction

    The most widely used antidote for paracetamol poisoning. Its efficacy as a specific antidote for paracetamol poisoning relies mainly on its ability to stimulate glutathione synthesis. Glutathione is essential in the metabolism of NAPQI (toxic paracetamol metabolite

    4 possible modes of action:

    • Increased glutathione availability
    • Direct binding of NAPQI
    • Provision of inorganic sulfate
    • Reduction of NAPQI back to paracetamol

    Dosing

    Paracetamol Toxicity

    • 150 mg/kg NAC diluted in 200 ml of 5% dextrose IV over 15-60 minutes., then
    • 50 mg/kg NAC diluted in 500 ml of 5% dextrose IV over 4 hours, then
    • 100 mg /kg NAC diluted in 1000 ml of 5% dextrose IV over 16 hours
    • 150 mg/kg in 100 ml of 5% dextrose over 15 minutes, then
    • 50 mg/kg in 250 ml of 5% dextrose over 4 hours, then
    • 50 mg/kg in 250 ml of 5% dextrose over 8 hours, then
    • 50 mg/kg in 250 ml of 5% dextrose over 8 hours.
    • 150 mg/kg in 3 ml/kg of 5% dextrose over 15 minutes, then
    • 50 mg/kg in 7 ml/kg of 5% dextrose over 4 hours, then
    • 50 mg/kg in 7 ml/kg of 5% dextrose over 8 hours, then
    • 50 mg/kg in 7 ml/kg of 5% dextrose over 8 hours

    References / Further Reading

    1. https://litfl.com/n-acetylcysteine/

  • Analgesia in Pregnancy

    Intrapartum Analgesia

    IM Pethidine
    • Dose: 1 mg/kg (usual dose: 50 mg, or 75 mg if weight >90 kg)
    •Prior to giving IM pethidine, latest CTG taken 1/2 – 1 hour ago must be normal. Pethidine is an opioid, can cause fetal respiratory distress.
    • Give together with IM Phenergen® (Promethazine) 25 mg

  • Angiotensin-Converting Enzyme Inhibitor (ACEI) & Angiotensin Receptor Blocker (ARB)

    How to initiate and monitor ACEi / ARB?

    🍊Repeat RP (potassium, creatinine) within 2 – 4 weeks of

    • Initiation of ACEi / ARB, OR
    • Increase / change in dose of ACEi / ARB

    🍊Continue ACEi / ARB if serum creatinine rises by less than 30% & normal serum potassium within 4 weeks following initiation of treatment / increase in dose

    🍊Stop / Reduce ACEi / ARB if

    • Pregnant women / Women plan for pregnancy
    • Serum creatinine rises more than 30% or persistent hyperkalaemia within 4 weeks following initiation or increased dose of ACEi / ARB, if mitigation strategies (as mentioned above) failed

    🍊If serum creatinine >30% after 2 – 4 weeks of initiation of therapy:
    Review for causes of AKI

    • Review concurrent medications (e.g. NSAIDs, diuretics)
    • History of taking supplements concurrently
    • Acute illness / Fever
    • Possible renal arterial stenosis

    Medical treatment (wherever indicated):

    • Correct dehydration / volume depletion

    🍊If hyperkalaemia after 2 – 4 weeks of initiation of therapy:

    • Review concurrent drugs
    • Advise for moderate / Low potassium diet
    • Consider adding other medical treatment e.g. diuretics, sodium bicarbonate, potassium binder

    =====

    • If worried, continue more frequent monitoring, until renal function and/or potassium level stabilised
    • Raised creatinine ≠ immediate discontinuation of ACEi or ARB
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