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.