PSA - drugs Flashcards
Name 3 weak opioids
codeine, dihydrocodeine, tramadol
What are the clinical implications for weak opioids?
Mild to moderate pain
Diarrhoea
Cough suppression
Prescribing doses and frequency for weak opioids used to manage pain
30-60mg every 4 hours as required (maximum 240mg daily)
Common adverse effects of weak opioids?
Constipation, biliary/ureteric spasm, dysphoria, sweating
Nausea/vomiting, drowsiness
Important adverse effects of weak opioids?
Respiratory depression (high doses) Hypotension (high doses) Paralytic ileus (dihydrocodeine)
In who should you avoid using weak opioids?
Avoid in COPD, acute asthma attack, acute respiratory depression, comatose patients and those at risk of paralytic ileus
What do weak opioids interact with?
CNS depressants (increased risk of respiratory depression) – alcohol, sedatives, hypnotics, general anaesthetics
What do you need to communicate to the patient when prescribing weak opioids?
Explain to patients that this medication could cause them to feel drowsy and that if this happens they should not drive or operate machinery. Patients should also be advised to avoid drinking alcohol while taking this medication
Name a few strong opioids
Buprenorphine, diamorphine, fentanyl, methadone,
oxycodone
Clinical indications for strong opioids?
Moderate to severe pain (including use in palliative care)
Acute diarrhoea (not first line)
Cough in terminal care
Dose and frequency of morphine administration
Morphine: 10mg s/c or IM every 4 hours (5mg every 4 hours if elderly, reduce dose in hepatic or renal impairment) , adjust according to response
Can also be administered by syringe driver or patient controlled analgesia (PCA) system
Adverse effects of strong opioids (same as weak)
Constipation, biliary/ureteric spasm, dysphoria, sweating
Nausea/vomiting, drowsiness
Important adverse effects of strong opioids
Respiratory depression Hypotension Sedation and coma Tolerance Physical and psychological dependence Overdose – this is reversed with naloxone
Who to avoid use of strong opioids in?
Avoid in acute respiratory depression, coma, head injury or raised ICP (opioids interfere with pupillary responses used in neurological assessment) and those at risk of paralytic ileus
What interacts with strong opioids?
CNS depressants (increased risk of respiratory depression) – alcohol, sedatives, hypnotics, general anaesthetics MAOIs (potentiate action of morphine)
What do you need to communicate to the patient when prescribing strong opioids? (same as weak)
Explain to patients that this medication could cause them to feel drowsy and that if this happens they should not drive or operate machinery. Patients should also be advised to avoid drinking alcohol while taking this medication.
Name two LMWHs
Dalteparin, Tinzaparin
What is the mechanism of action of LMWHs?
LMWH binds to antithrombin 3 and accelerates its action: Inhibition of factor Xa in the common pathway of the clotting cascade
Factor Xa is needed to convert prothrombin to thrombin, therefore LMWHs inhibit coagulation
What are the clinical indications for LMWHs?
Prophylaxis of venous thromboembolism (VTE)
Treatment of VTE before adequate oral anticoagulation (with warfarin) is established
Treatment of acute MI and unstable coronary artery disease, PE, DVT
Important adverse effects of LMWHs?
Haemorrhage
Heparin-induced thrombocytopenia (discontinue in these patients)
Hyperkalaemia
Who should you avoid giving LMWHs to?
Avoid in haemophilia and other haemorrhagic disorders, thrombocytopenia, recent cerebral haemorrhage, severe hypertension, peptic ulcer disease, acute bacterial endocarditis, following major trauma and in patients with known hypersensitivity to heparins
What do LMWH interact with?
NSAIDs (increased risk of haemorrhage)
ACE inhibitors, ARBs (increased risk of hyperkalaemia)
Antiplatelet agents (increased risk of haemorrhage)