Interactions Flashcards
CYP540 inducers
DECREASES THE CONC OF DRUG MET BY CYP450 Carbamazepine Rifampicin Alcohol Phenytoin Griseofulvin Phenobarbitone Sulphonylureas
CYP450 inhibitors
INCREASE THE CONC OF DRUGS MET BY CYP450 Sodium valproate Isoniazid Cimetidine Ketoconazole Fluconazole Alcohol AND Grapefruit Chloramphenicol Erythromycin Sulfonamides . Ciprofloxacin Omeprazole Metronidazole
Dugs metabolised by CYP450
warfarin combined pill theophylline corticosteroids tricyclic antidepressants pethidine statins
Clopidogrel and statins
Clopi and statins are met by CYP450
omeprazole is C/I with clopidogrel
safest is pantoprazole
lansoprazole and rabeprazole are OK
Simvastatin interactions
bezafibrate and ciprofibrate - 10 MG OD
amiodarone/amlodipine/ranolazine - 20 MG OD
verapamil/diltiazem - 20 MG OD
elbasvir with grazoprevir - 20 MG OD
bempedoic acid/bempedoic acid with ezetimibe - MAX 20 MG OD or 40 MG OD if severe hypercholesterolaemia with high risk CVD
Erythromycin/clarithromycin/telithromycin - C/I
Itraconazoles - C/I
Ciclosporins - C/I
antivirals - C/I
Atorvastatin interactions
Ciclosporins (if unavoidable) - 10 MG OD
elbasvir with grazoprevir - 20 MG OD
letermovir WITHOUT ciclosporin - 20 MG OD
sofosbuvir with velpatasvir and voxilaprevir - 20 MG OD
anion exchange resin for heterozygous familial hypercholesterolemia - 40 MG OD
Drug-induced HypERNatraemia
Diuretics sodium bicarbonate sodium chloride corticosteroids anabolic steroids oestrogens
Drug-induced HypONatraemia
ACEI Heparin Diuretics antidepressants (citalopram, etc...) antipsychotics carbamazepine S+S inc: weakness, fatigue or low energy, headache, N+V, muscle spasm, cramps, confusion, irritability.
drug that lower the seizure treshold
tramadol Imipenem 4th gen cephalosporin ciprofloxacin isoniazid penicillin antipsychotics lithium MAOI SSRI SNRI TCA Aminophylline Theophylline pseudoephedine
medication causing QT prolongation
Erythromycin Clritthromycin Fluconazole Ketoconazole Dronedarone Quinidine Amiodarone Flecainide Methadone antipsychotics Citalopram/escitalopram amitriptylline domperidone droperidol ondansetron/Granisetron
Drug induced hyperkalaemia
Potassium-sparing diuretics aldosterone antagonist b-blockers ACEI digoxin trimethoprim and co-trimaxozole NSAID heparin
drug that cause hypokalaemia
Laxatives (excessive use - stool excretion) Diuretics (renal excretion) Beta-blockers (high dose - taken up by cells) Corticosteroids (renal excretion) Insulin (taken up by cells) Theophylline (taken up by cells) Penicillins (high dose - renal excretion) Verapamil (overdose - taken up by cell) Gentamicin Sodium Bicarbonate Amphotericin Echinochandin antifungals Cisplatin Parecoxib
citalopram and NSAID
increased risk of hyponatraemia
increased risk of GI bleeding
drugs that cannot be stopped abruptly
SSRI MAOI LAMOTRIGINE (2 weeks) Corticosteroids Hypnotics and anxiolytics morphine/ALL opioids Buprenorphine antipsychotics antiparkinson drugs mirtazapine lithium venlafaxine (need 4 weeks) Benzodiazepines Pregabalin - over 1 week
Atorvastatin C/I
ciclosporin - VERY BIG MAX 20 MG
Clarithromycin - AVOID
Amlodipine - theoric, pravastatin, rosuvasttain preferred
Drugs causing hypoMagnesium
PPI Ciclosporin short bowel syndrome Zoledronic acid parathyroid hormone amphoterin B Hydroxyzine Hydrochloride
Hypercalcaemia S+S
loss of appetite
N+V
Constipation and abdominal pain
need to drink more fluids and urinate more
tiredness, weakness and muscle pain
confusion, disorientation and difficulty thinking
headaches
depression
can be caused by tamoxifen, potentiate digoxin toxicity, thiazide-like diuretic, lithium, Vit A, VIT D and Calcium ca lead to hyperC
Lithium interactions
Aminophylline - HypoK + torsades de pointes Amisulpride - QT prolongation Amiodarone - QT interval prolongation Amitriptyline - inc neurotoxicity Apomorphine - inc QT prolongation thiazide like diuretics - HyopK, torsade de pointes, inc lithium conc Steroids - HypoK loop diuretic - HypoK (torsade de pointe) and inc lithium conc ARB - inc conc of lithium ACEI - inc conc of lithium Carbamazepine - inc neurotoxicity risk NSAID - inc conc of lithium Chlorpromazine - inc QT prolongation SSRI - QT prolongation Clarithromycin/erythromycin - QT prolongation Diltiazem - risk neurotoxicity domperidone - risk QT prolongation Tetracyclines - inc risk lithium toxicity Fluconazole - QT interval prolongation mefloquine/quinine - QT prolongation
Domperidone
Linked with arrhythmias and cardiac pb - max 1 week treatment
X in cardiac and GI pb