Drug Interactions + Adverse Effects Flashcards
Panadol adverse effects + nursing considerations
Risk of hepatotoxicity (liver) with elevated doses - >8g in 24 hr
Monitor LFTs
NSAIDS adverse effects + nursing considerations
Risk of GIT bleeding
* COX-1 produces a prostaglandin that protects the stomach mucosa from stomach acid
* Block production of thromboxane A2 important for clotting
Induce renal impairment
* Inhibition of synthesis of prostaglandin that dilates the vessels to the kidney allowing for improved blood flow (kidneys start to fail when filtration drops below 210mL/min)
* Prostaglandins dilate the afferent arteriole of the kidney.
Increased risk of cardiovascular events
* Changes in clotting action and glomerular filtration (increase sodium and water retention).
Monitor EUC, use lowest effective dose for shortest period of time
NSAIDS drug interactions
Anti-coagulants: increased anti-coagulant effect.
Drugs that aim to increase serum potassium as reduced glomerular filtration can result in hyperkalaemia.
Opioid adverse effects and nursing considerations
Risk of respiratory depression, bradycardia, and hypotension = represses respiratory drive in medulla > less O2 intake reduces the amount available to muscles.
Constipation = act on mu receptors in the GIT
Dependency = controlled drug
Naloxone = opioid antagonist, helps with constipation
Assess level of sedation, give laxatives
Opioid drug interactions
Benzodiazepines: inhibit GABA in the CNS resulting in reduced respiratory drive and chemoreceptor response to CO2.
Gabapentin/Pregabalin: inhibits GABA in the CNS, aimed at reducing seizures, can enhance opioid effects and increase risk of respiratory depression.
Macrolide adverse effects and nursing considerations
Macrolides may lead to super infections, alter the electrical conduction of the heart (increase QT interval) and may result in dysrhythmia.
Avoid rapid infusions.
Aminoglycoside (Gentamycin) adverse effects and nursing considerations
Aminoglycosides can cause nephrotoxicity (small amount of the drug can be retained in kidney tissue), ototoxicity (can generate free radicals that damage sensory cells in the ears), neurotoxicity (neuromuscular paralysis).
Monitor EUC, blood plasma trough levels, creatinine clearance, urinalysis, dizziness, tinnitus, confusion.
Macrolide drug interactions
Inhibit hepatic CYP 450 enzyme which is involved in metabolising drugs, this can cause drug toxicity of e.g. warfarin, digoxin, theophylline, midazolam, drugs that prolong the QT interval.
Aminoglycoside (Gentamycin) drug interactions
If given with 1) vancomycin can increase risk of ototoxicity or nephrotoxicity 2) loop diuretics risk of hearing loss 3) non-steroidal anti-inflammatories could reduce renal function.
Beta Lactams adverse effects and nursing considerations
May cause anaphylaxis (rare in penicillins); allergies (urticaria, rash, itching, angioedema); nausea; diarrhoea; super infections; IV infusions are high in Na; nephrotoxicity.
Some bacteria produce beta lactamase which digests the beta lactam coating on a drug rendering it ineffective. Penicillins are particularly susceptible. Cephalosporins somewhat susceptible.
Be aware of allergies, avoid rapid infusions, monitor EUCs and LFTs.
Penicillins drug interactions
Gentamicin as is incompatible with aminoglycosides; anticoagulants as can inhibit platelet aggregation in high doses.
Cephalosporins drug interactions
Aminoglycosides; anticoagulants as can interfere with vitamin K metabolism; aspirin/NSAIDS as can have an inhibitory effect of platelets; drugs with risk of renal impairment.
Carbapenems drug interactions
Risk lowering the seizure threshold
Glycopeptides (Vancomycin) drug interactions
Aminoglycosides increase risk of ototoxicity and nephrotoxicity
Anaesthetics increase the risk of vancomycin adverse reactions.
Glycopeptides (Vancomycin) adverse effects and nursing considerations
GIT issues.
Nephrotoxicity or ototoxicity in renal impaired patients.
Rare - hypersensitivity (fever, chills); red man syndrome (infusion reaction).
Monitor renal function, hearing, avoid rapid infusions, monitor trough levels in patient’s with renal impairment.
Protease inhibitor examples
Ritonavir (treat HIV)
Ritonavir adverse effects
Cardiac conduction abnormalities due to their effect on lipids, increasing production of lipoproteins (hypercholesterolaemia and hypertriglyceridemia).
May worsen diabetes by reversibly inhibiting insulin responsive glucose transporter Glut 4, reducing glucose tolerance.
Oseltamivir adverse effects
Most effective is administered within 48 hours of infection.
Beta Blocker adverse effects and nursing considerations
Cause bradycardia, hypotension, bronchospasm, alteration of glucose metabolism (block the release of insulin from the pancreas).
Slowly reduce when treatment is ceased to prevent complications e.g. rebound hypertension. Can mask signs of hypoglycaemia e.g. tachycardia and tremor. Do not give if HR<60bpm.
Digoxin adverse effects and nursing considerations
Narrow therapeutic range > toxicity
* Worsening of arrythmias; bradycardia/tachycardia; extrasystole
* N+V due to action on the vomiting centre in the brain
* CNS and visual disturbances
Hypokalaemia due to diuretic effect of improved renal blood flow.
Monitor for SS of toxicity; EUC; LFT; do not administer if HR<60bpm
Digoxin drug interactions
Increase digoxin effects: beta-blockers; calcium preparations; adrenaline etc.
Increase risk of toxicity: medications that increase potassium loss e.g. large infusions of glucose, frusemide.
Amiodarone adverse effects and nursing considerations
- Worsening of arrythmias.
- Long half life (6 days for someone who is healthy, but up to 140 days).
- Pulmonary toxicity: Accumulates in adipose tissue, may induce the production of toxic O2 radicals, which can directly damage cells. promotes the accumulation of phospholipids in tissues.
- Contraindicated for renal patients.
Close medical and nursing supervision; regular obs; ECGs; EUC; chest x-rays; continuous cardiac monitoring for IV infusion.
Amiodarone drug interactions
Can slow down the removal of other medications from your body, which may affect how they work.
Digoxin: interferes with digoxin excretion; risk of toxicity; severe bradycardia, hypotension.
Dihydropyridines adverse effects
Cerebral dilation > increased intracranial pressure > throbbing headache.
Postural hypotension.
Baroreceptor reflex > reflex tachycardia.
Verapamil adverse effects
Constipation: effect the muscle that forms part of the walls of your bowel.
Bradycardia.
Loop Diuretic adverse effects
Dehydration.
Electrolyte imbalance: hypokalaemia, hyponatraemia, hypocalcaemia, hypomagnesemia.
Thiazide Diuretic adverse effects
Dehydration.
Electrolyte imbalance: hypokalaemia, hyponatraemia, hypERcalcaemia, hypomagnesemia.
Increased uric acid.
Dizziness, postural hypotension, muscle cramps.
Thiazide Diuretic drug interactions
Increase the effects of many drugs e.g. digitalis; lithium; loop diuretics.
Decrease the effects of anticoagulants; anti-gout agents.
Effects are increased by corticosteroids and anticholinergics.
Effects are decreased by NSAIDS.
Potassium Sparing Diuretic adverse effects
Electrolyte imbalances: hyponatraemia, hyperkalaemia.
Weakness, headache, N+V.
Potassium Sparing Diuretic drug interactions
Potassium supplements (increased risk of hyperkalaemia); ACE inhibitors (potassium sparing effect); NSAIDS (increased risk of hypotension).
ACE Inhibitor adverse effects
Hypotension; dizziness; headache; renal impairment; hyperkalaemia (due to decreased secretion of aldosterone which regulates K+ excretion).
Monitor EUC; monitor K levels.
ACE Inhibitor drug interactions
Limit K+ supplements; review use of NSAIDS (increased risk of renal impairment).
GTN adverse effects
Vasodilatory effects = hypotension; flushing; palpitations; syncope.
Administered sublingually. Fast acting absorption.
Statins adverse effects and nursing considerations
Myalgia; Mild GIT disturbance; Headache; Insomnia; Dizziness.
Rare but serious = Myopathy; Rhabdomyolysis (destruction of striated muscle).
Baseline bloods (EUC; LFT); short acting statins are more effective when taken PM; avoid stopping statins if symptoms of CAD.
Warfarin nursing considerations
Regular INR to keep between 2-4 (1.0 in pt not on warfarin); monitor any diet, lifestyle, or medication changes.
Avoid dietary changes, avoid foods high in vit K
Warfarin drug interactions
Warfarin is highly protein bound, other medications may displace it allowing for increased anticoagulant activity.
Heparin adverse effects and nursing considerations
Haemorrhage; haematoma in pt with hypertension; dissecting aneurysm, haemophilia, peptic ulcer, ulcerative colitis, threatened abortion.
Coagulation bloods (aPTT) every four hours when on IV infusion or before each injection.
Heparin drug interactions
Avoid with medications that have risks of inducing bleeding; avoid with medications that have anti-coagulation effect.
Antihistamines; nicotine; nitro-glycerine; digitalis; tetracyclines reduce effectiveness of heparin.
Aspirin adverse effects and nursing considerations
GI irritation, asymptomatic blood loss, increased bleeding time.
The plasma half-life is only 20 minutes; Because platelets cannot generate new COX, the effects of aspirin last for the duration of the life of the platelet (≈10 days). After a single dose of aspirin, platelet COX activity recovers by ≈10% per day as a function of platelet turnover.
Beta-2 Agonist adverse effects and nursing considerations
Inhalation is the preferred route. Nebulised medication carries risk of infection.
Enhanced sympathetic effect: tremor, palpitation, headache, insomnia.
Hypokalaemia.
Tachycardia.
Atrovent adverse effects and nursing considerations
Dry mouth; throat irritation. Rinse out mouth after using inhaler so that drug doesn’t sit on the mucosa and have systemic absorption and effects. We only want local effects.
Inhaled Corticosteroid adverse effects
Dyspnoea, oral pharyngeal candidacies (thrush); bruising.
Systemic effects from high doses: adrenal suppression; bone density loss; glaucoma; skin thinning and bruising.
Rinse mouth with water and gargle following inhalation to avoid ingesting medication.
Systemic Corticosteroid adverse effects
Sodium and water retention; oedema; hypertension; hyperglycaemia; diabetes; osteoporosis; delayed wound healing; bruising.
Adrenal suppression when stopped quickly. When taken for a long time, adrenal glands decrease the production of cortisol, person can be left with insufficient cortisol in times of stress.
Systemic Corticosteroid drug interactions
Enhance Beta2 agonist actions.
Epinephrine adverse effects
Tachycardia, hypertension, headache, anxiety, apprehension, palpitations, diaphoresis, nausea, vomiting, weakness, and tremors.
Hyperglycaemia: adrenaline causes SNS activation = increase cortisol = gluconeogenesis = increased BGL.
Mylanta adverse effects and nursing considerations
Can reduce the effect of oral medications > take 2 hours away from other medications.
Proton Pump Inhibitor adverse effects and nursing considerations
Change in gastric pH can reduce the absorption of certain meds (e.g. digoxin)
Reduce the rate of elimination of certain drugs.
Ranitidine (H2 Antagonist) adverse effects and nursing considerations
H2 receptors are also located in:
- Brain: headaches, dizziness, confusion
- Skin: rash, pruritus
- Heart: hypotension, dysrhythmia
Reduction of gastric acid –> increase risk of bacterial growth in the stomach.
Ranitidine drug interactions
Strong inhibitor of cytochrome P450 enzyme in the liver –> reduce drug metabolism/rate of elimination.
Metformin adverse effects
GIT intolerance (take with or after food); anorexia.
Malabsorption of vitamin B12.
Lactic acidosis.
Metformin changes the way that the liver makes glucose. A by product of this is lactic acid, which can be an intestinal irritant in the gut.
5HT3 Antagonist adverse effects
Usually well tolerated.
Constipation (serotonin plays a role in gastric motility); headache; dizziness.
QT prolongation: blocks cardiac potassium/sodium channels. Avoid in pt with risk of QT prolongation.
Serotonin syndrome: serotonin accumulation causes CNS overstimulation
Use with caution in pt with electrolyte imbalances.
5HT3 Antagonist drug interactions
Avoid with drugs that increase serotonin levels. E.g. anti-depressants, tramadol.
Dopamine 2 Antagonist adverse effects
Akathisias (motor restlessness, agitation, inability to remain still):
Antagonism of the dopaminergic receptors in the mesocortical and mesolimbic pathways. The involvement of the noradrenergic and serotoninergic pathways has also been suggested. No single hypothesis has been satisfactory.
CNS toxicity. Females > hyperprolactinaemia, anovulatory amenorrhoea. Males > erectile dysfunction.
Contraindicated in bowel obstruction or when increased GIT motility could be dangerous.
Contraindicated in Parkinson’s disease.
Should not be used for >12 weeks: may cause irreversible tardive dyskinesia (uncontrolled movement).
Osmotic Laxative adverse effects
Salt based laxatives should be used with caution in the elderly due to potential to cause dehydration and electrolyte abnormalities (arrythmias).
Fluid loss and dehydration.
Cramping, bloating, flatulence due to the production of bacteria that feed on the osmotic laxatives.
Contraindicated in intestinal obstruction
Saline laxatives contraindicated in renal or hepatic impairment and cardiac conditions.
Indigestible sugars and alcohols (lactulose) contraindicated in diabetes.
Stimulant Laxative adverse effects
Abdominal cramping, N+V, diarrhoea, weakness, fluid and electrolyte imbalance.
Senna can sometimes discolour the urine.
Contraindicated in intestinal obstruction, severe N+V or abdominal pain.
