DRUG NAME: WARNING SIGNS:
AMIODARONE
- Signs and symptoms of hypo- or hypert
- Corneal microdeposits may develop - r
with vision. Drivers may be dazzled by
NOTES: MONITORING: night. If vision impaired or if optic neur
- Long half-life = - Thyroid function neuropathy occurs, STOP AMIODARON
50 days - Liver function - Progressive shortness of breath or coug
- Loading doses - Serum potassium (pneumonitis, pulmonary toxicity)
may be - Chest X-ray - Clinical signs of liver disease e.g. jaundi
required - ECG (w/ IV use) - Neurological effects of tremor, periphe
e.g. develop numbness and tingling in h
INTERACTIONS:
- Phototoxic skin reactions e.g. burning s
- Long half-life = potential for drug interactions to occur for several
followed by erythema, and persistent s
weeks to months after treatment has stopped
discoloration on light-exposed areas
- ↑ plasma concentration = coumarins, dabigatran, digoxin,
flecainide, phenindione, phenytoin
- ↑ risk of ventricular arrhythmias = amisulpride, atometine, ACTIONS REQUIRED:
chloroquine, citalopram, disopyramide, escitalopram, - Advise patient = shield skin from direct
haloperidol, hydroxychloroquine, lovefloxacin, lithium, and for several months after stopping t
mizolastine, mefloquine, moxifloxacin, phenothiazines, pimozide, or to use a wide-spectrum sunscreen
quinine, sulpiride, telithromycin, tolterodine, tricyclics - Warn drivers = may be dazzled by head
- ↑ risk of bradycardia, AV bloc and myocardial depression = beta- night
blockers, diltiazem, verapamil - Warn patients = clinical effects may occ
- ↑ risk of myopathy = simvastatin months after stopping the medicine
,DRUG NAME: WARNING SIGNS:
DIGOXIN
- Cardiac = arrhythmias, heart block
- Neurological = weakness, lethargy, dizz
headache, mental confusion, psychosis
NOTES: MONITORING: - Gastrointestinal = anorexia, nausea, vo
- Therapeutic Range = 0.8 – - Serum electrolytes (K+, Mg2+, diarrhoea, abdominal pain
2mcg/L Ca2+) = hypokalemia, - Visual = blurred and/or yellow vision
- Loading doses may be required hypomagnesaemia, hypercalcemia can
potentiate toxicity
- Renal function ACTIONS REQUIRED:
- Heart rate (>60bpm) - Advise patient = report imme
INTERACTIONS: to a doctor if any warning sign
- ↑ plasma concentration =
alprazolamamiodarone, ciclosporin, diltiazem, - Dosage forms have different b
itraconazole, lercanidipine, macrolides, availabilities (check SPC)
mirabegron, nicardipine, nifedipine, quinine, - IV = 100%
spironolactone and verapamil
- ↓ plasma concentration = St. John’s wort - Tablet = 50-90%
- Hypokalaemia (↑ risk of cardiac toxicity & digoxin - Elixir = 75%
toxicity) when concomitant administration with =
acetazolamide, amphotericin, loop diuretics or MAJOR ROUTE OF ELIMINATION:
thiazides and related diuretics - Renal excretion
- Drugs that impair renal function affect plasma - Hepatic metabolism to active
digoxin conc e.g. NSAIDs, ACEIs
metabolites
, WARNING SIGNS:
DRUG NAME:
- Toxicity [SNATCHED]:
PHENYTOIN - Slurred speech
- Nystagmus (uncontrolled repet
movements)
MONITORING:
NOTES: - Ataxia
- MOA = Binds to neuronal Na+ channels in their
- Serum conc
inactive state; prolongs inactivity - ECG + BP with IV use - Confusion
- Therapeutic range: 10 – 20mg/L (or 40-80 - Liver function - Hyperglycemia
micromol/litre) - FBC - Diplopia (blurred vision)
- Non-linear relationship between dose and plasma - Serum folate - Skin disorders e.g., rash, toxic epid
drug concentrations: small changes in dose/missed necrolysis
dose/change in drug absorption = large change in
- Vit D
plasma drug conc. - Blood disorders e.g., fever, sore th
ulcers, unexplained bruising or ble
INTERACTIONS: (leucopenia, aplastic anemia, meg
- ↑ plasma concentration = amiodarone, chloramphenicol, cimetidine,
disulfiram, diltiazem, fluconazole, fluoxetine, miconazole, topiramate,
anemia)
trimethoprim (also increase antifolate effect), metronidazole, clarithromycin, - Suicidal thoughts
telithromycin (avoid during and 2 weeks after phenytoin) - Low vitamin D levels e.g., rickets,
- ↓ plasma concentration = rifamycin's, St John’s wort, theophylline, ACTIONS REQUIRED:
itraconazole, ciclosporin - Advise patient = report immediate
- ↑ metabolism of corticosteroids, oestrogens, progestogens and coumarins
doctor if any warning signs appear
(possibility of ↓ anticoag effect but ↑ also reported)
- Anticonvulsant effect possibly antagonized by antipsychotics, mefloquine, SSRIs, - Caution when dispensing = brand-
tricyclics, and tricyclic-related antidepressants preparations.
- ↓ plasma conc. of aripiprazole, itraconazole, oestrogens and progestogens - Dose conversion: 100mg phenytoi
(reduced contraceptive effect), theophylline and tricyclics è 92mg phenytoin base
AMIODARONE
- Signs and symptoms of hypo- or hypert
- Corneal microdeposits may develop - r
with vision. Drivers may be dazzled by
NOTES: MONITORING: night. If vision impaired or if optic neur
- Long half-life = - Thyroid function neuropathy occurs, STOP AMIODARON
50 days - Liver function - Progressive shortness of breath or coug
- Loading doses - Serum potassium (pneumonitis, pulmonary toxicity)
may be - Chest X-ray - Clinical signs of liver disease e.g. jaundi
required - ECG (w/ IV use) - Neurological effects of tremor, periphe
e.g. develop numbness and tingling in h
INTERACTIONS:
- Phototoxic skin reactions e.g. burning s
- Long half-life = potential for drug interactions to occur for several
followed by erythema, and persistent s
weeks to months after treatment has stopped
discoloration on light-exposed areas
- ↑ plasma concentration = coumarins, dabigatran, digoxin,
flecainide, phenindione, phenytoin
- ↑ risk of ventricular arrhythmias = amisulpride, atometine, ACTIONS REQUIRED:
chloroquine, citalopram, disopyramide, escitalopram, - Advise patient = shield skin from direct
haloperidol, hydroxychloroquine, lovefloxacin, lithium, and for several months after stopping t
mizolastine, mefloquine, moxifloxacin, phenothiazines, pimozide, or to use a wide-spectrum sunscreen
quinine, sulpiride, telithromycin, tolterodine, tricyclics - Warn drivers = may be dazzled by head
- ↑ risk of bradycardia, AV bloc and myocardial depression = beta- night
blockers, diltiazem, verapamil - Warn patients = clinical effects may occ
- ↑ risk of myopathy = simvastatin months after stopping the medicine
,DRUG NAME: WARNING SIGNS:
DIGOXIN
- Cardiac = arrhythmias, heart block
- Neurological = weakness, lethargy, dizz
headache, mental confusion, psychosis
NOTES: MONITORING: - Gastrointestinal = anorexia, nausea, vo
- Therapeutic Range = 0.8 – - Serum electrolytes (K+, Mg2+, diarrhoea, abdominal pain
2mcg/L Ca2+) = hypokalemia, - Visual = blurred and/or yellow vision
- Loading doses may be required hypomagnesaemia, hypercalcemia can
potentiate toxicity
- Renal function ACTIONS REQUIRED:
- Heart rate (>60bpm) - Advise patient = report imme
INTERACTIONS: to a doctor if any warning sign
- ↑ plasma concentration =
alprazolamamiodarone, ciclosporin, diltiazem, - Dosage forms have different b
itraconazole, lercanidipine, macrolides, availabilities (check SPC)
mirabegron, nicardipine, nifedipine, quinine, - IV = 100%
spironolactone and verapamil
- ↓ plasma concentration = St. John’s wort - Tablet = 50-90%
- Hypokalaemia (↑ risk of cardiac toxicity & digoxin - Elixir = 75%
toxicity) when concomitant administration with =
acetazolamide, amphotericin, loop diuretics or MAJOR ROUTE OF ELIMINATION:
thiazides and related diuretics - Renal excretion
- Drugs that impair renal function affect plasma - Hepatic metabolism to active
digoxin conc e.g. NSAIDs, ACEIs
metabolites
, WARNING SIGNS:
DRUG NAME:
- Toxicity [SNATCHED]:
PHENYTOIN - Slurred speech
- Nystagmus (uncontrolled repet
movements)
MONITORING:
NOTES: - Ataxia
- MOA = Binds to neuronal Na+ channels in their
- Serum conc
inactive state; prolongs inactivity - ECG + BP with IV use - Confusion
- Therapeutic range: 10 – 20mg/L (or 40-80 - Liver function - Hyperglycemia
micromol/litre) - FBC - Diplopia (blurred vision)
- Non-linear relationship between dose and plasma - Serum folate - Skin disorders e.g., rash, toxic epid
drug concentrations: small changes in dose/missed necrolysis
dose/change in drug absorption = large change in
- Vit D
plasma drug conc. - Blood disorders e.g., fever, sore th
ulcers, unexplained bruising or ble
INTERACTIONS: (leucopenia, aplastic anemia, meg
- ↑ plasma concentration = amiodarone, chloramphenicol, cimetidine,
disulfiram, diltiazem, fluconazole, fluoxetine, miconazole, topiramate,
anemia)
trimethoprim (also increase antifolate effect), metronidazole, clarithromycin, - Suicidal thoughts
telithromycin (avoid during and 2 weeks after phenytoin) - Low vitamin D levels e.g., rickets,
- ↓ plasma concentration = rifamycin's, St John’s wort, theophylline, ACTIONS REQUIRED:
itraconazole, ciclosporin - Advise patient = report immediate
- ↑ metabolism of corticosteroids, oestrogens, progestogens and coumarins
doctor if any warning signs appear
(possibility of ↓ anticoag effect but ↑ also reported)
- Anticonvulsant effect possibly antagonized by antipsychotics, mefloquine, SSRIs, - Caution when dispensing = brand-
tricyclics, and tricyclic-related antidepressants preparations.
- ↓ plasma conc. of aripiprazole, itraconazole, oestrogens and progestogens - Dose conversion: 100mg phenytoi
(reduced contraceptive effect), theophylline and tricyclics è 92mg phenytoin base
