Medicines 19 Flashcards
What is the treatment for TB?
“RIPE”
Rifampicin
Isoniazid (with pyridoxine)
Pyrazinamide
Ethambutol
Start all at the same time however R & I are for a total of 6 months, P & E are for a total of 2
Which of the penicillins should be taken on an empty stomach and which ones can be taken with or without food?
With or without food: Pivmecillinam, amoxicillin, coamoxiclav
On an empty stomach:
Co-fluampicil (flucloxacillin + ampicillin), Flucloxacillin, Ampicillin, Phenoxymethylpenicillin,
Benzylpenicillin (also known as penicillin G) is not taken orally because it is unstable in the acidic environment of the stomach, which would destroy the drug before it could be absorbed.
Name some aminosalicylates:
and what key side effect should you look out for with their treatment?
Mesalazine
Olsalazine
Balsazide
Sulfasalazine
Blood dyscrias
Which antibiotics are associated with intracranial hypertension?
Antibiotics Associated with Intracranial Hypertension
Tetracyclines
Examples:
Tetracycline
Doxycycline
Minocycline (highest risk within this class)
Fluoroquinolones (Less commonly reported)
Examples:
Ciprofloxacin
Levofloxacin
What medication is used to treat hyperuricaemia in patients with haematological malignancy?
Rasburicase - a recombinant urate oxidase
Which medications cause a sore mouth in chemotherapy treatment and how is this prevented?
A sore mouth is a common complication of cancer chemotherapy; it is most often associated with fluorouracil, methotrexate, and the anthracyclines. It is best to prevent the complication. Good oral hygiene (rinsing the mouth frequently and effective brushing of the teeth with a soft brush 2–3 times daily) is probably beneficial. For fluorouracil, sucking ice chips during short infusions of the drug is also helpful.
Once a sore mouth has developed, treatment is much less effective.
Which cytotoxic drugs dont cause bone marrow syndrome as per BNF?
All cytotoxic drugs except vincristine sulfate and bleomycin cause bone-marrow suppression
Which Cytotoxic drugs are most emetogenic?
Emetogenic refers to the ability of a substance, such as a drug or treatment, to cause nausea and vomiting.
Mildly emetogenic treatment—fluorouracil, etoposide, methotrexate (less than 100 mg/m2, low dose in children), the vinca alkaloids, and abdominal radiotherapy.
Moderately emetogenic treatment—the taxanes, doxorubicin hydrochloride, intermediate and low doses of cyclophosphamide, mitoxantrone, and high doses of methotrexate (0.1– 1.2 g/m2).
Highly emetogenic treatment—cisplatin, dacarbazine, and high doses of cyclophosphamide.
WHat medication causes Urothelial toxicity?
Urothelial toxicity refers to damage to the urothelium, the protective lining of the bladder and urinary tract, caused by certain drugs or substances. This toxicity can lead to symptoms such as hematuria (blood in urine), dysuria (painful urination), and, in severe cases, hemorrhagic cystitis.
Haemorrhagic cystitis is a common manifestation of urothelial toxicity which occurs with the oxazaphosphorines, cyclophosphamide and ifosfamide; it is caused by the metabolite acrolein. Mesna reacts specifically with this metabolite in the urinary tract, preventing toxicity. Mesna is used routinely (preferably by mouth) in patients receiving ifosfamide, and in patients receiving cyclophosphamide by the intravenous route at a high dose (e.g. more than 2 g) or in those who experienced urothelial toxicity when given cyclophosphamide previously.
What are the main uses for the schedule 2 controlled drugs (fentanyl, methadone, morphine)
Acute severe pain – post-operative and acute myocardial infarction
Relief of chronic pain when weaker analgesics don’t work
Relief of breathlessness in end-of-life care
Relieve breathlessness and anxiety in pulmonary oedema with oxygen, furosemide and nitrates
Methadone for severe pain or treatment of opioid dependence
What are the key side effects with opioids?
Respiratory depression – reduces respiratory drive
Bradycardia, hypotension, feeling dizzy
Euphoria and detachment
Neurological depression in higher doses
Nausea and vomiting – by activating CTZ
Pupillary constriction – pinpoint pupils
Constipation – due to activation of µ receptors in small intestine = reducing smooth muscle tone
Itching – due to histamine release in the skin
Tolerance and dependence – withdrawal reaction
What are the key contraindications of methadone?
Reduce dose in hepatic failure and renal impairment and elderly
Do not give in respiratory failure
Avoid in biliary colic – cause spasm of the sphincter of Oddi – worsens pain
Avoid in heart failure secondary to lung disease
Caution and reduce dose in adrenocortical insufficiency
Caution in cardiac arrhythmias and cor pulmonale
key contraindications:
Contraindicated in Pheochromocytoma – tumour of adrenal gland tissue
Antipsychotics – increased risk of ventricular arrhythmias when methadone given with antipsychotics that prolong the QT interval
Cyp inducers (Carbamazepine) – decrease methadone concentration
Cyp inhibitors (Itraconazole) – increase concentration of methadone – increased risk of ventricular arrhythmias
Ketoconazole – increased risk of ventricular arrhythmias – Avoid
QT- INTERVAL PROLONGATION
What are some key cautions/contraindications with fentanyl?
Reduce dose in hepatic failure and renal impairment and elderly
Do not give in respiratory failure
Avoid in biliary colic – cause spasm of the sphincter of Oddi – worsens pain
Avoid in heart failure secondary to lung disease
Caution and reduce dose in adrenocortical insufficiency
Caution in cardiac arrhythmias and cor pulmonale
key contraindications:
Caution in diabetes when giving lozenges – actiq
Caution in mucositis with buccal use as absorption may be increased
Do not give patches to those whose requirements for analgesia are constantly changing
Antifungals – increase concentrations of Fentanyl
Avoid with buprenorphine
What are the key cautions/contraindications with buprenophine?
Caution in impaired consciousness
With transdermal use: other opioids should not be administered within 24 hours of patch removal (long duration of action) (in adults)
When used for adjunct in the treatment of opioid dependence: hepatitis B infection (in adults); hepatitis C infection (in adults); pre-existing liver enzyme abnormalities (in adults)
Caution with use with hepatotoxic drugs
Diamorphine, methadone, morphine, oxycodone, tramadol – opioid withdrawal when given together
Avoid with fentanyl
with methadone specifically what factors should be carefully monitored regarding QT interval?
Patients with the following risk factors for QT-interval prolongation should be carefully monitored while taking methadone: heart or liver disease, electrolyte abnormalities, or concomitant treatment with drugs that can prolong QT interval; patients requiring more than 100 mg daily should also be monitored.
Which formulations are used for methadone with:
Opioid dependence
Cough in palliative care
Severe pain
Opioid dependence - ORAL SOLUTION
Cough in palliative care - By mouth using LINCTUS
Severe pain - By mouth, or by subcutaneous injection, or by intramuscular injection
What key counselling points should be considered for opioids ?
Look out for signs of breathlessness
Dose increase should be no more than 50% of previous dose
Do not stop treatment suddenly
Methadone solution is 2.5 times the strength of methadone linctus. Many preparations of methadone oral solution is licensed for drug addiction only but some are also licensed for severe pain
Fentanyl patches: apply on a dry hairless body away from heat. if needed, shave the area a few days before you apply the patch to make sure shaving does not irritate your skin Change every 72 hours.
What is the effect of rifampicin on opioids?
Rifampicin – decreases effect of morphine, fentanyl, codeine and methadone (CYP Inducer)
What are some key general side effects, cautions and contraindications with NSAIDs?
Side effects
GI toxicity – Ibuprofen has lowest risk
Renal impairment
CV events – MI and stroke
Hypersensitivity reactions – bronchospasm, angioedema
Fluid retention – can worsen heart failure
Cautions and contraindications; conditions
Avoid in severe renal impairment
Avoid in heart failure (Sever heart failure Avoid all NSAIDs, mild-moderate- Avoid COX-2 inhibitors, diclofenac, and high-dose ibuprofen (2400 mg or more daily) )
Avoid in liver failure
Avoid in known NSAID-hypersensitivity
Avoid in asthma – may worsen symptoms if patient can tolerate it then allow
May exacerbate crohn’s disease – caution
Caution in elderly
What are the main side effects of paracetamol?
Causes liver failure in overdose – metabolised by CYP enzymes to a toxic metabolite NAPQI – avoided with glutathione precursor: acetylcysteine
What cautions and contraindications are there with paracetamol?
Reduce dose in people at increased risk of liver toxicity = chronic alcohol toxicity
Or reduced glutathione stores: malnutrition, low body weight <50Kg, severe hepatic impairment
What interactions are there with paracetamol?
Mainly drugs that can cause hepatotoxicity,
However, Phenytoin, Carbamazepine – increases metabolism of paracetamol so may increase liver toxicity after overdose
Coumarins – may enhance anticoagulant effects
What key side effects are there with SSRIs?
GI upset
Appetite and weight disturbance (loss or gain)
Hypersensitivity reactions: skin rash
Hyponatraemia – especially in elderly- confusion and reduced consciousness
Suicidal thoughts and behaviour may be increased
Lower seizure threshold
Citalopram prolongs QT interval – can predispose to arrhythmias
Increase risk of bleeding
Serotonin syndrome – at high doses and other antidepressants = causes autonomic hyperactivity, altered mental state and neuromuscular excitation
What can sudden withdrawal of SSRIs cause?
GI upset
Neurological symptoms
influenza-like symptoms
Sleep disturbance
What cautions is there with SSRIs?
Caution in epilepsy - lowers seizure threshold
Caution in peptic ulcer disease - increased risk of bleeding
Caution in young people – increased risk of suicidal thoughts
Reduce dose in hepatic impairment - Can lead to drug accumulation
Caution in diabetes - affect blood glucose control
What key interactions are there with SSRIs?
Do not give with MAOIs – both increase synaptic serotonin levels = serotonin syndrome. Do not start until at least 1 week after stopping SSRI
NSAIDs, Aspirin – provide gastroprotection =increased risk of GI bleed
Anticoagulants – increased risk of bleed
Other drugs that prolong QT interval – antipsychotics
Fentanyl – -increased serotonergic effects
Tramadol – increased risk of CNS toxicity
Amiodarone – citalopram may increase risk of ventricular arrhythmias – avoid
Erythromycin – increased risk of ventricular arrhythmias – avoid
Antiepileptics – anticonvulsant effects antagonised by SSRIs – lower seizure threshold
Lithium – increased CNS effects
