Drug(s) Side effects Contraindications Interactions
Oesophagitis, atypical femoral Severe RI,
Alendronic fractures, hypophosphatemia, hypocalcaemia, upper Calcium, antacids and iron salts =
acid osteonecrosis of jaw and GI disorders, smokers, reduced absorption of AA
external auditory canal dental disease
Thickened milk Reduced absorption of ACEIs,
preparations, Na/K+ tetracyclines, digoxin,
Alginates Al = constipation
products in renal bisphosphonates, levothyroxine
and Antacids Mg = diarrhoea
failure, sucrose Increased excretion of aspirin and
products in diabetics lithium (increased alkalinity of urine)
Acute attacks of gout, Azathioprine toxicity
Rash (SJS or TEN?), allergy,
Allopurinol recurrent skin rash, Amoxicillin = skin rash
trigger of acute gout
severe allergy ACEIs and TDs = allergy
Hypotension, pneumonitis,
bradycardia, AV block, Risk of digoxin toxicity
Severe hypotension,
hepatitis, photosensitivity, CCBs = bradycardia, heart failure, AV
Amiodarone heart block, active
grey discolouration, thyroid block
thyroid disease
abnormalities, corneal Grapefruits = increased side effects
microdeposits, hepatotoxicity
Antimuscarinic effects,
sedation, hypotension, Elderly, CVD, epilepsy,
MAOIs = hypertension,
arrhythmias, prolonged QT, constipation, raised
Amitriptyline hyperthermia, serotonin syndrome
convulsions, hallucinations, intraocular pressure,
Prolonged QT drugs
breast changes, sexual prostatic hypertrophy
dysfunction, EPS
Swelling, flushing, headache, Unstable angina,
Amlodipine -
palpitations severe aortic stenosis
<16s (Reye’s
GI irritation, GI ulceration, syndrome), aspirin Antiplatelets and anticoagulants =
Aspirin
bronchospasm, tinnitus allergy, 3rd trimester, bleeding risk
peptic ulcers, gout
Atenolol, Fatigue, cold extremities, Non-DHP CCBs (verapamil and
propranolol, headache, impotence in men, Asthma, heart block diltiazem) = heart failure,
bisoprolol sleep disturbances, nightmare bradycardia, asystole
Atorvastatin, Headache, myopathy, Pregnancy, hepatic Increased risk of side effects =
simvastatin rhabdomyolysis impairment amiodarone, macrolides, diltiazem
Hyponatraemia,
Bendroflumethiazide, hypokalaemia, cardiac Hypokalaemia, gout,
indapamide NSAIDs = reduced efficacy of diuretic
arrhythmias, impotence in hyponatraemia
men
Elderly, respiratory Alcohol and opioids = sedation
Sedation, coma, dependence, impairment, Increased effects of BZPs with
Benzodiazepines
airway obstruction neuromuscular amiodarone, diltiazem, macrolides,
disease, liver failure fluconazole, protease inhibitors
Oral thrush, hoarse voice,
Beta-2 COPD Pts with a H/O
pneumonia (in COPD), adrenal Beta blockers = reduced efficacy of
agonist + ICS pneumonia, children,
suppression, growth delay, inhalers
inhalers CVD
tremor, tachycardia, cramps
Reduced absorption of iron,
bisphosphonates, tetracyclines and
Calcium Dyspepsia, constipation Hypercalcaemia levothyroxine
Sodium bicarbonate = precipitation
risk so avoid
Reduced efficacy of warfarin,
Dizziness, ataxia, allergy, Antiepileptic allergy oestrogens and progestogens
Carbamazepine
oedema, hyponatraemia syndrome Macrolides = increased conc. of CZP
Reduced antiepileptic efficacy with
, SSRIs, TCAs, antipsychotics, tramadol
GI upset, AB-associated colitis, C. difficile infections, Warfarin = increased bleeding risk
Cephalosporins
allergy anaphylaxis Aminoglycosides = nephrotoxicity
Cetirizine,
chlorphenamine Sedation (chlorphenamine) Severe liver disease MAOIs = increased antimuscarinic SE
Theophylline = theophylline toxicity
Calcium and antacids = reduced
Allergy, rupture of muscle
absorption of ciprofloxacin
tendons, prolonged QT, C. Prolonged QT, at risk
Ciprofloxacin NSAIDs = increased seizure risk
difficile colitis, reduced of seizures
Prolonged QT
seizure threshold
Prednisolone = increased tendon
rupture risk
Allergy, AB-associated colitis, Erythromycin and clarithromycin are
Clarithromycin,
erythromycin
cholestatic jaundice, Macrolide allergy CYP450 inhibitors (not azithromycin)
prolonged QT, ototoxicity Prolonged QT
Reduced efficacy with CYP450
Active bleeding, inhibitors (i.e. PPIs) as it’s a pro-
Clopidogrel Bleeding, thrombocytopenia surgery, R/H drug requiring activation by CYP450
impairment enzymes
Antiplatelets, NSAIDs = bleeding
Nausea, constipation, Respiratory disease, Antipsychotics, BZPs, TCAs =
Co-codamol
drowsiness renal impairment increased sedation
Drowsiness, dry throat, dry Hepatic BZPs, opioids = sedation
Cyclizine,
mouth, palpitations, encephalopathy, Ipratropium, tiotropium =
promethazine
tachycardia prostatic hypertrophy antimuscarinic effects
Heart block, renal
Bradycardia, GI disturbances, Digoxin toxicity = loop and thiazide
failure, hypokalaemia,
Digoxin rash, dizziness, blurred or diuretics, amiodarone, CCBs,
hypomagnesaemia,
yellow vision spironolactone and quinine
hypercalcaemia
Allergy, oesophageal
Reduced AB absorption = calcium,
irritation, tooth Pregnancy, BF, <12s,
Doxycycline antacids, iron
discolouration, renal impairment
Warfarin = increased bleeding risk
photosensitivity
Impotence, reduced libido,
Finasteride gynaecomastia, hair growth, Pregnancy -
breast cancer
Increased concentration of
phenytoin, carbamazepine, warfarin,
Hepatitis, allergy (rash), Pregnancy, moderate
diazepam, simvastatin, gliclazide
Fluconazole hepatotoxicity, prolonged QT, RI, prolonged QT, liver
Clopidogrel = reduced antiplatelet
cutaneous reactions disease
effect
Prolonged QT
Allergy, hyponatraemia,
MAOIs = serotonin syndrome
suicidal thoughts, reduced Epilepsy, peptic ulcer
Fluoxetine, Aspirin, anticoagulants, NSAIDs = GI
seizure threshold, bleeding, disease, young people,
sertraline bleeding
serotonin syndrome, hepatic impairment
Prolonged QT drugs
prolonged QT
Hypovolaemia,
Dehydration, hypotension,
dehydration, hepatic Lithium toxicity
Furosemide low electrolyte state, tinnitus,
encephalopathy, Digoxin toxicity
hearing loss
hypokalaemia, gout
Nephrotoxicity, ototoxicity Neonates, elderly, RI, Loop diuretics = ototoxicity
Gentamicin
(irreversible) myasthenia gravis Cephalosporins = nephrotoxicity
Reduced hypoglycaemic effect =
GI upset, hypoglycaemia,
Gliclazide Hepatic impairment prednisolone, thiazides, loop
allergy
diuretics
Oesophagitis, atypical femoral Severe RI,
Alendronic fractures, hypophosphatemia, hypocalcaemia, upper Calcium, antacids and iron salts =
acid osteonecrosis of jaw and GI disorders, smokers, reduced absorption of AA
external auditory canal dental disease
Thickened milk Reduced absorption of ACEIs,
preparations, Na/K+ tetracyclines, digoxin,
Alginates Al = constipation
products in renal bisphosphonates, levothyroxine
and Antacids Mg = diarrhoea
failure, sucrose Increased excretion of aspirin and
products in diabetics lithium (increased alkalinity of urine)
Acute attacks of gout, Azathioprine toxicity
Rash (SJS or TEN?), allergy,
Allopurinol recurrent skin rash, Amoxicillin = skin rash
trigger of acute gout
severe allergy ACEIs and TDs = allergy
Hypotension, pneumonitis,
bradycardia, AV block, Risk of digoxin toxicity
Severe hypotension,
hepatitis, photosensitivity, CCBs = bradycardia, heart failure, AV
Amiodarone heart block, active
grey discolouration, thyroid block
thyroid disease
abnormalities, corneal Grapefruits = increased side effects
microdeposits, hepatotoxicity
Antimuscarinic effects,
sedation, hypotension, Elderly, CVD, epilepsy,
MAOIs = hypertension,
arrhythmias, prolonged QT, constipation, raised
Amitriptyline hyperthermia, serotonin syndrome
convulsions, hallucinations, intraocular pressure,
Prolonged QT drugs
breast changes, sexual prostatic hypertrophy
dysfunction, EPS
Swelling, flushing, headache, Unstable angina,
Amlodipine -
palpitations severe aortic stenosis
<16s (Reye’s
GI irritation, GI ulceration, syndrome), aspirin Antiplatelets and anticoagulants =
Aspirin
bronchospasm, tinnitus allergy, 3rd trimester, bleeding risk
peptic ulcers, gout
Atenolol, Fatigue, cold extremities, Non-DHP CCBs (verapamil and
propranolol, headache, impotence in men, Asthma, heart block diltiazem) = heart failure,
bisoprolol sleep disturbances, nightmare bradycardia, asystole
Atorvastatin, Headache, myopathy, Pregnancy, hepatic Increased risk of side effects =
simvastatin rhabdomyolysis impairment amiodarone, macrolides, diltiazem
Hyponatraemia,
Bendroflumethiazide, hypokalaemia, cardiac Hypokalaemia, gout,
indapamide NSAIDs = reduced efficacy of diuretic
arrhythmias, impotence in hyponatraemia
men
Elderly, respiratory Alcohol and opioids = sedation
Sedation, coma, dependence, impairment, Increased effects of BZPs with
Benzodiazepines
airway obstruction neuromuscular amiodarone, diltiazem, macrolides,
disease, liver failure fluconazole, protease inhibitors
Oral thrush, hoarse voice,
Beta-2 COPD Pts with a H/O
pneumonia (in COPD), adrenal Beta blockers = reduced efficacy of
agonist + ICS pneumonia, children,
suppression, growth delay, inhalers
inhalers CVD
tremor, tachycardia, cramps
Reduced absorption of iron,
bisphosphonates, tetracyclines and
Calcium Dyspepsia, constipation Hypercalcaemia levothyroxine
Sodium bicarbonate = precipitation
risk so avoid
Reduced efficacy of warfarin,
Dizziness, ataxia, allergy, Antiepileptic allergy oestrogens and progestogens
Carbamazepine
oedema, hyponatraemia syndrome Macrolides = increased conc. of CZP
Reduced antiepileptic efficacy with
, SSRIs, TCAs, antipsychotics, tramadol
GI upset, AB-associated colitis, C. difficile infections, Warfarin = increased bleeding risk
Cephalosporins
allergy anaphylaxis Aminoglycosides = nephrotoxicity
Cetirizine,
chlorphenamine Sedation (chlorphenamine) Severe liver disease MAOIs = increased antimuscarinic SE
Theophylline = theophylline toxicity
Calcium and antacids = reduced
Allergy, rupture of muscle
absorption of ciprofloxacin
tendons, prolonged QT, C. Prolonged QT, at risk
Ciprofloxacin NSAIDs = increased seizure risk
difficile colitis, reduced of seizures
Prolonged QT
seizure threshold
Prednisolone = increased tendon
rupture risk
Allergy, AB-associated colitis, Erythromycin and clarithromycin are
Clarithromycin,
erythromycin
cholestatic jaundice, Macrolide allergy CYP450 inhibitors (not azithromycin)
prolonged QT, ototoxicity Prolonged QT
Reduced efficacy with CYP450
Active bleeding, inhibitors (i.e. PPIs) as it’s a pro-
Clopidogrel Bleeding, thrombocytopenia surgery, R/H drug requiring activation by CYP450
impairment enzymes
Antiplatelets, NSAIDs = bleeding
Nausea, constipation, Respiratory disease, Antipsychotics, BZPs, TCAs =
Co-codamol
drowsiness renal impairment increased sedation
Drowsiness, dry throat, dry Hepatic BZPs, opioids = sedation
Cyclizine,
mouth, palpitations, encephalopathy, Ipratropium, tiotropium =
promethazine
tachycardia prostatic hypertrophy antimuscarinic effects
Heart block, renal
Bradycardia, GI disturbances, Digoxin toxicity = loop and thiazide
failure, hypokalaemia,
Digoxin rash, dizziness, blurred or diuretics, amiodarone, CCBs,
hypomagnesaemia,
yellow vision spironolactone and quinine
hypercalcaemia
Allergy, oesophageal
Reduced AB absorption = calcium,
irritation, tooth Pregnancy, BF, <12s,
Doxycycline antacids, iron
discolouration, renal impairment
Warfarin = increased bleeding risk
photosensitivity
Impotence, reduced libido,
Finasteride gynaecomastia, hair growth, Pregnancy -
breast cancer
Increased concentration of
phenytoin, carbamazepine, warfarin,
Hepatitis, allergy (rash), Pregnancy, moderate
diazepam, simvastatin, gliclazide
Fluconazole hepatotoxicity, prolonged QT, RI, prolonged QT, liver
Clopidogrel = reduced antiplatelet
cutaneous reactions disease
effect
Prolonged QT
Allergy, hyponatraemia,
MAOIs = serotonin syndrome
suicidal thoughts, reduced Epilepsy, peptic ulcer
Fluoxetine, Aspirin, anticoagulants, NSAIDs = GI
seizure threshold, bleeding, disease, young people,
sertraline bleeding
serotonin syndrome, hepatic impairment
Prolonged QT drugs
prolonged QT
Hypovolaemia,
Dehydration, hypotension,
dehydration, hepatic Lithium toxicity
Furosemide low electrolyte state, tinnitus,
encephalopathy, Digoxin toxicity
hearing loss
hypokalaemia, gout
Nephrotoxicity, ototoxicity Neonates, elderly, RI, Loop diuretics = ototoxicity
Gentamicin
(irreversible) myasthenia gravis Cephalosporins = nephrotoxicity
Reduced hypoglycaemic effect =
GI upset, hypoglycaemia,
Gliclazide Hepatic impairment prednisolone, thiazides, loop
allergy
diuretics
