Therapuetics Flashcards
Which drugs are included in the BNF?
All licensed drugs used in UK
If a person prescribes a different dose of a drug that indicated what is this called?
Off-label
What are late effects of chemotherapy?
Impact brain, spinal cord and nerves (also endocrine and reproductive) so can cause hearing loss, peripheral neuropathy, lung fibrosis, cardiomyopathy and myelodysplasia
Which chemotherapy drug can cause long-term hearing loss?
Cisplatin
What can TCAs do to the pupils?
Dilate
What will happen to pupils on drug overdose?
Constrict
What pupil effects do opioids have?
Pinpoint pupils
How can you directly assess drug compliance?
Measure levels in blood or urine
How does compliance change with increasing the number of drugs?
Decreases
Which drug can be used for hypertension, migraine prophylaxis and angina?
Beta-blockers
Which drug can be used for generalised seizures, trigeminal neuralgia and manic depression?
Carbamazepine
What is pharmacokinetics?
How the body works on the drug
What is pharmacodynamics?
How the drug works on the body
What type of receptor is a beta-adrenoceptor? How does it work?
G protein coupled: receptor binding leads to interaction with G protein coupled with intracellular activation (cAMP/cGMP or ion channel)
What type of receptors are kinase-linked?
Insulin receptors
Give examples of DNA-linked receptors and what/how do they work?
Located in cell nucleus (nuclear receptors) and promotes/inhibits protein synthesis - e.g. glucocorticoid receptors, thyroid receptors, vitamin D receptors
Which drugs block Na voltage dependent channels?
Anaesthetics e.g. lidocaine
What type of channels are L-type calcium channels?
Voltage gated
Which enzyme does aspirin inhibit?
Cyclo-oxygenase
What type of medication targets HMGCoA reductase?
Statins
What type of medication is paroxetine?
SSRI
What drug class does omeprazole belong to?
PPIs
Do antacids have specific or non-specific function?
Non-specific
What 3 things do drug-receptor interactions depend on?
- chemical composition of the drug
- stereochemical composition of the drug
- ability of drug to reach receptor
What 3 things can impact the affinity of a drug?
- other drugs
- aging
- genetic mutations
What is efficacy?
The relative ability of a drug to impart a functional change on the receptor.
How do partial and full agonists vary in terms of efficacy?
A partial agonist binds and activates the receptor with only partial efficacy.
What is the potency of a drug? What does it depend on?
The amount of the drug required for a given intensity of effect. This is proportional to affinity and efficacy.
What is plotted on the axes of a dose-response curve?
Concentration (x) vs drug effect (y)
What are the 3 possible mechanisms for increased tolerance?
- Down regulation of receptors
- Decreased receptor binding affinity
- Modulation of downstream response to initial signal
What can increased tolerance make a patient experience?
Withdrawal reactions
How long does tolerance to a medication take to increase?
Days to weeks
What off-target effect can opioids cause?
EConstipation
Which 2 effects need to be considered to find the therapeutic index?
Toxic and therapeutic effect
Which drugs have a particularly narrow therapeutic index?
Gentamycin, vancomycin, lithium, digoxin, warfarin
How can you monitor drugs with a narrow therapeutic index?
Measure concentration of drug in the blood
How does a “dose” differ from a “dosage”?
Dose: total quantity of active agent taken in/absorbed at one time
dosage: includes characteristics of the organism e.g. body weight, surface area
What are the 4 processes that occur when drugs are taken?
- Uptake
- Distribution
- Metabolism
- Elimination
What are the 3 types of routes of administration?
- Topical: local effect
- Enteral: systemic effect via digestive tract
- Parenteral: systemic effect via other routes - IV, transdermal (nicotine patches), transmucosal, inhalational
What does affinity mean?
The probability of the drug occupying a receptir at any given time
What is meant by the efficacy of a drug?
The ability of a drug-receptor complex to produce a maximum functional response
What drug class does buprenorphine belong to and how does it act?
Opioid which acts as a partial agonist
Drug activity in terms of amount required to produce an effect of given intensity - what word is this?
Potency
What word describes the relative ability of a drug-receptor complex to produce a maximum functional response?
Efficacy
What is therapeutic efficacy?
The effectiveness of a drug to produce an effect
What do you use to determine the dose of a step up painkiller if someone is already on one?
Conversion tables
Do IM or subcut injections have a faster onset?
IM
Which drugs are given intrathecally?
Anaesthesia and chemotherapy
What type of drugs are given by transdermal route?
Lipophillic - nicotine patches, oestradiol (menopause), fentanyl (severe pain)
Are modified release and normal release formulas interchangeable?
No
Which drugs could exacerbate/trigger asthma?
Beta blockers and aspirin
How can you manage asthma non-pharmacologically?
Avoid triggers, personalised asthma plan, secondary prevention (smoking cessation, weight loss intervention, breathing exercises)
Which inhalers are given first to someone with asthma?
SABA (selective beta-2 agonist) and low dose inhaled corticosteroid
What type of inhaler is terbutaline?
SABA
Apart from inhalers, how else can SABAs be given?
Nebuliser, IV infusion, oral tablets
What inhalers are beclomethasone, fluticasone and budesonide all examples of?
Inhaled corticosteroids
What would cause you to step up someone’s asthma treatment?
- Exacerbation in last 2 years
- Symptoms need SABA 3x a week
- Symptoms at least 1 night a week
What are adverse effects of SABAs?
Tremor, tachycardia, hypokalaemia
What are adverse effects of ICS?
Sore throat/oral candidiasis, osteoporosis in adults, growth suppression in children
How could you reduce risk of oral candidiasis using an inhaler?
Use a spacer or rinse mouth after inhalation
What type of inhalers are salmeterol and formoterol?
LABA
Which 2 types of inhalers are included in combination inhalers?
ICS and LABA
What would you do if a patient was on a LABA and ICS combined inhaler and were not responding to treatment at all?
Stop LABA and increase dose of ICS
What would you do if a patient was on a LABA and ICS combined inhaler and were responding to LABA but of asthma control was not sufficient?
Continue this therapy and either increase dose of ICS to medium or introduce LTRA, LAMA or theophylline
What are examples of high dose asthma therapies? How would you manage the patient if it got to this stage?
High dose ICS, or adding a fourth drug (LRTA, SR theophylline, LABA tablet or LAMA). Refer to specialist!
What is the final step of pharmacological asthma management?
Lowest dose of daily steroid tablets, high dose ICS. Refer to specialist.
What should you assess and do in an asthma review?
Symptoms, lung function, inhaler technique and adherence, adjust dose, update self-management plan, move up and down as appropriate
What is the highest dose of ICS possible?
800mg beclomethasone
How long is the duration of action for LABAs?
12 hours
What type of inhalers are salmeterol and formoterol?
LABAs
What drug is montelukast?
leukotriene receptor antagonist
What side effects can leukotriene receptor antagonists cause?
Hypersensitivity reaction and GI upset
What is theophylline derived from?
Xanthine
What are adverse effects of xanthine derivatives?
Cardiac arrhythmias and seizures
What class of inhaler is tiotropium?
LAMA
Why might someone be responding poorly to their asthma treatment?
- Poor compliance: understanding, polypharmacy, complicated, stress/psychological
- Trigger presence
- Poor inhaler technique
- Wrong diagnosis - GORD, COPD, bronchiectasis
What is clinically classified as acute severe asthma?
- Cannot complete sentences, HR>=110bpm, RR>=25
4. PEFR <33% predicted
How is acute severe asthma treated?
- Admit to hospital
- Oxygen
- Nebulised salbutamol or terbutaline (SABA)
- Prednisolone 40-50mg PO or hydrocortisone 100mg IV (if cannot swallow)
- If response poor… inhaled ipratropium bromide 500mg every 4-6 hours via O2 driven nebuliser OR IV beta-agonist (magnesium sulphate or aminophylline)
- Over next few days - education and support: nebs, steroids, find reason, anxiety expected, compliance, technique
- Asthma follow-up at GP and nurse specialists
What is meant by “difficult” asthma?
Persistent symptoms/frequent exacerbations despite high-dose therapy
What can be used under strict adherence for difficult asthma?
Monoclonal antibodies
What 4 thing are assessed in a COPD assesment?
- Amount of bronchospasm
- Infections - do they need antibiotics?
- Right-sided HF?
- How much emphysema? - more has more limitations to treating
Which 3 factors contribute to asthma airway narrowing?
Bronchial muscle contraction, mucosal swelling/inflammation (mast cell and basophil degranulation –> inflammatory mediators) and increased mucus production
What is the pathophysiology of COPD?
- Emphysema: alveolar destruction due to protease-antiprotease imbalance (proteases from noxious particles overwhelm).
- Bronchitis: Hyperplasia and hypertrophy of mucus-secreting glands in submucosa of bronchi
What is the steps in management of COPD?
- SABA or SAMA as needed
- If no asthmatic features = LABA + LAMA
- LABA + LAMA + ICS
- Oral bronchodilators - theophylline
- Always use antibiotics if indicated, vaccinations (flu, pneumococcal), mucolytic (carbocisteine tablets for chronic productive cough), treat HF with diuretics, oxygen therapy for respiratory failure, smoking cessation
- Manage exacerbations: controlled O2, corticosteroids, antibiotics, nebulised bronchodilators, physiotherapy
If you get to the stage in COPD management to add tiotropium, what else should you do?
Tiotropium is a LAMA so stop SAMA (ipratropium). Add SABA and then LABA and inhaled corticosteroids if still needed.
What venturi mask should you start on for type 2 respiratory failure?
Blue (24%; 2L/min)
Order of venturi masks, percentage oxygen and rate?
- Blue - 24% - 2L/min
- White - 28% - 4L/min
- Orange - 31% - 6L/min
- Yellow - 35% - 8L/min
- Red - 40% - 10L/min
- Green - 60% - 15L/min
What are bupropion (Zyban) and varenicline (champix) tablets used for? What drug class are each of them?
Smoking cessation
- Bupropion is an SSRI and mechanism is not understood - contraindicated in <18yo, pregnant, breastfeeding or history of seizures
- Varenicline is a selective nicotine receptor partial agonist - contraindicated in <18yo, pregnant, breastfeeding and caution with psychiatric history
Why is particle size important for inhaled drugs?
It is proportional to area of deposition
- > 10micrometers deposited in mouth to large airway
- <5micrometers in small airways
- around 2 micrometres in alveoli
- > 1micrometers may be exhaled again
What are the 3 methods to deliver drugs by inhalation?
- Metered dose inhalers
- Breath actuated device
- Nebuliser
Why might you add a spacer device to a metered dose inhaler (MDI)?
Reduces need for coordination and risk of oral thrush
What are negatives of using spacers?
Reduce amount of medication absorbed in system and less convenient to carry
How much of the prescribed dose in a nebuliser reaches the lungs?
10%
What are ADRs?
Adverse drug reactions - a response to a drug which is noxious and unintended at normal doses
What type of drugs can cause impaired renal function if not monitored in the lab?
ACEi
Which common drug can cause haemorrhage or elevated INR if not therapeutically monitored?
Warfarin
What is Stevens-Johnson syndrome?
Rare, serious disorder of skin usually as a result of a reaction to medication. Starts as flu-like symptoms, then a red/purple rash that spreads to form blisters which eventually die and peel off. MEDICAL EMERGENCY.
What is a less severe ADR similar to Stevens-Johnson syndrome?
Erythema multiforme
What is type of arrhythmia is Torasades de Pointes and what is it a complication of?
Polymorphic ventricular tachycardia which occurs in long-QT syndrome
Which drugs can influence the development of Torsades de Pointes?
Antiarrhythmic drugs (quinidine, procainamide, disopyramide)
Antipsychotics
TCAs
Methadone, erythromycin and ketoconazole
Which drugs can cause a butterfly rash? What is this condition called?
Drug-induced Lupus
- Hydralazine (vasodilator) and procainamide (antiarrhythmic can cause)
Which drugs can induce gingival hyperplasia?
Phenytoin (anti-epileptic) and amlodipine (Ca2+ channel blocker)
How can ARDs be classified?
- Type A Reactions/Augmented Reactions: dose-dependent and predictable on basis of pharmacology of the drug
- Type B Reactions/Bizarre Reactions: idiosyncratic and not predictable
What type of ARDs are drowsiness and respiratory depression to codeine?
Type A
What 3 things do DoTS use to classify ARDs?
- Dose of drug
- Time course of reaction
- Relevant susceptibility factors
What patient characteristic can make them more susceptible to haemolysis (ARD) with chloroquine?
G6PD deficiency
What patient characteristic can make them more susceptible to parkinsonism (ARD) with prochlorperazine?
Elderly
What patient characteristic can make them more susceptible to cough (ARD) with ACEi?
Female
What patient characteristic can make them more susceptible to ARD with phenytoin?
Pregnancy
How does cranberry juice contribute to increased risk of ARDs?
Cytochrome P450 enzyme inhibition
What patient characteristic can make them more susceptible to deafness (ARD) with gentamycin?
Renal failure as these drugs are eliminated by the kidneys
What ADR is icatibant used for?
ACEi induced life-threatening angioedema affecting airway, head and neck as it is a selective bradykinin B2 receptor antagonist
What ARD is idarucizumab used for? What type of drug is it?
A monoclonal antibody for dabigatran-prolonged coagulation
What ARDs are intravenous lipid emulsions used for?
Local anaesthetic toxicity (e.g. severe cardiotoxic effects of lidocaine), intravascular infection or rapid absorption effects from injections in highly vascular sites.
Name a pharmovigilance tool
Yellow card scheme
What symbol is used to indicate a new drug and vaccine in order to encourage reporting of ARDs?
Black upside down triangle
What are the 3 stages of hypertension?
- Clinic BP 140/90mmHg or higher/ABPM 135/85mmHg or higher
- 160/100mmHg or 150/95mmHg
- 180/110mmHg