Therapeutic drug monitoring & High risk drugs Flashcards
What is the difference between HYPERglyceamia and HYPOglyceamia symptoms?
HYOGLYCEAMIA-Think how you feel if you have not eaten sugar for a while:Dizzy, head hurts, shaky, hungry, cannot see or think straight, sweatyHYPERGLYCEAMIA:Just think how you feel if you’re BUZZING:Dry mouth, need water, lots of weeing, wetting bed, stomach painblood glucose concentration ishigh so fluid moves out of cells into circulation due to osmosis so you get dehydration
What is an ionotrope? What is a positive and what is a negative ionotrope?
A drug that alters the force or energy of heart contractionsSo positive ionotrope (e.g. Digoxin, Amiodarone): increases force of contractions of heart, used in conditions such as decompensate Heart Failure, shock (severe hypotension)and Myocardial Infarction as they get blood pumping again!NB: these do not increase rate, digoxin actually decreases the rate, just increase force of contraction. Digoxin used as rate control in AF, Amiodarone used as Rhythm.Negative ionotropes: decrease force of contractions of the heart, used in conditions such as Hypertension to bring blood pressure down and Angina. Examples: Rate limiting CCB’s, cardio-selectivebeta blockers e.g. bisoprolol, carvedilol, metoprolol, some anti-arrhythmics such asflecainide
What is the desired serum concentration of Digoxin?
1 - 2 mcg / L
What is the difference between bradycardia and tachycardia? What is the the classified pulse rate for these?
Bradycardia: slow heart rate: pulse under 60 bpmTachycardia: fast heart rate: pulse over 100 bpm
What are the symptoms of DIGOXIN toxicity? (i.e. levels over 2 mcg/ L)
Gastro:Nausea and vomittingAbdominal painAnorexia (weight loss)
Cardiac:Bradycardia- (HR under 60 bpm) heart slowed down too much by digoxinArrythmias (irregular heart beat)
Mental:Delirium (confusion)
Visual disturbance- blurred, seeing yellow, blind spots
Digoxin needs close monitoring. It slows the heart rate, but increases the force of contraction. We need to monitor the heart rate: When should we be worried?
If it falls below 60 BPM (i.e. becomes bradycardic)
We need to monitor the plasma concentration of Digoxin closely. When should levels be taken?
at least 6 HOURS after a dose given
Digoxin toxicity can be fatal. What electrolyte imbalance can precipitate digoxin toxicity?
HYPOKALEAMIA is a big one. We manage this by giving K+ sparing diuretics (e.g. spironolactone) and K+ supplements. Hypomagnesaemia Hypocalcaemia
How is digoxin excreted? Therefore what do we need to monitor and decrease dose if impaired?
Renally decrease dose if patient has renal impairment
What is digoxin used in?
Most use in persistent & permanent Atrial Fibrilation as RATE control
Has a role in Heart FailureRole in Atrial flutters
Amiodarone is used in the rhythm control of AF.Digoxin is used as rate control.interaction between these 2 drugs?
Amiodarone INCREASES plasma concentration of digoxin It is an ENZYME inhibitor but not one of the P450’s (so not part of SICKFACES)
Digoxin dose needs to be decreased by 50% if given with Amiodarone
Digoxin is metabolised by the CYP450 enzyme system, primarily 2C19. It therefore has many interactions. Can you think of any drugs that increase its concentration?
Macrolides: ErythromycinClarythromycin, Azithromycin
Ciclosporin
Itraconazole
Amiodarone (but not through CYP)
Rifampicin and St Johns Wort are both CYP450 enzyme inhibitors. What TDM drug do they reduce the concentration of?
Digoxin
Why does Digoxin interact with Diuretics?
Diuretics (Loop and thiazide/ thiazide- like) may cause HYPOKALEAMIADigoxin toxicity is precipitated by HYPOkaleamiaTherefore be careful with:Furosemide, Bumetanide Bendroflumethiazide, indapamide, chlortolidone
Potassium sparing diuretics are Okay:Amiloride TriamtereneSpironolactone (this can increase [Digoxin]), Eplerenone
What drugs other than diuretics can interact with digoxin due to their Hypokaleamic effects?
Amphotericin (Antifungal!)
Can you think why ACE inhibitors and NSAID’s interact with digoxin?
Remember digoxin is excreted renally and caution in kidney impairmentACE inhibitors and NSAID’s can both decrease kidney function and precipitate digoxin toxicity
What happens if a CCB is administered to someone on Digoxin?
Plasma conc of digoxin increased by:Diltiazem Nicardepine Nifedipine Verapamil
(also increases risk of AV BLOCK & bradycardia [slows rate])
What are the signs of Lithium toxicity?
GI disturbance warning signs: Vomitting, Diarrohea
Then Mostly CNS effects: Fine Tremor to start then coarse tremor, Involuntary movement (ataxia) Involuntary eye movement (Nystagmus)
Blurred vision
Thirst- due to hypernatreamia
Severe toxicity (level over 2 mmol/L): ConvulsionsComaRenal failuire
Lithium can cause problems in some of our organs. What are these, what would be the signs if their function had altered?
Kidney- monitor renal function
Sign of decline: Polyuria, Polydipsia
Thyroid - usually hypothyroidism Signs: unexplained fatigue
Benign intracranial hypertension (high BP in brain) Signs: persistent headache, visual disturbance
You know the target range for lithium is 0.4 - 1.0 mmol/L.What is the target in acute episodes of mania?
0.8 - 1.0 mmol/ L- upper end of the range!
What three drugs do you legally have to provide a patient alert card with?
Lithium Steroids Anticoagulant
Lithium interacts with ACE inhibitors/ ARB’s NSAIDS What is this interaction?
Ace inhibitors / ARB’s and NSAIDs can decrease renal perfusionLithium excreted by Kidneys
Lithium levels risk= lithium toxicity
Why does Lithium interact with the Diuretics (loop, thiazide AND potassium-sparing)?
Diuretics can cause electrolyte disturbance Hyponatreamia may be a result Lithium levels influenced by sodium levels- lithium toxicity
Which antibiotic could possibly cause Lithium toxcity/ levels to rise?
Metronidazole
Please note there is increased risk of _____ when Lithium is given with things like _____, _________, __________ & ______________
There is increased risk of ____ when Lithium is given with ________
Please note there is increased risk of neurotoxicity when Lithium is given with things like methyldopa, phenytoin, carbamazepine & the rate limiting CCB’s diltiazem and verapamil
There is increased risk of EPSE’s when Lithium is given with antipsychotics
What type of seizures can phenytoin be used in?
Focal Tonic- clonic Myoclonic But not first/ 2nd line in any. Its use is fizzling out.
All types of seizure but Absent!
Desired therapeutic range for Phenytoin?Why is it so important to monitor phenytoin levels?
10 - 20 mg/ L= 40- 80 micromol/L
Non-linear relationship between dose and plasma conc: small change in dose= big change in conc
What are the symptoms of Phenytoin toxicity?
CNS: Nystagmus (involuntary eye movement) Ataxia (involuntary body movement)Slurry speech
Confusion
suicidal thoughts
HYPERGLYCEAMIA
Double vision (diplopia), blurred vision
NB: Similar to Lithium toxicity: remember the differentials (hyperglyceamia, no convulsions)
Phenytoin is related to SKIN & BLOOD disordersWhat does the patient need to look out for?
Skin- look out for RASH
Phenytoin also causes: HIRSUTISM (excess hair growth)
gingival hypertrophy (enlarged gums)
acne
Blood disorder: Fever, sore throat, mouth ulcers, bruising, bleeding
With phenytoin, we should monitor ________ &______ with IV use. Should also monitor _____ function, especially in elderly
ECG & BP with IV use
LIVER Phenytoin hepatically metabolised: Caution in Hepatic impairment
What is the desired range of Theophylline levels?
10 - 20 mg/ L = 55 - 110 micromol/ L
(mg/ L= same as phenyotin!
and digoxin is 1 - 2 mcg/ L so similar! and you know Lithium!)
Phenytoin is an interesting drug when it comes to interactions as it itself is an enzyme inducer, but its levels are effected by other enzyme inducers/ inhibitors. It can (effectively) induce its own metabolism.This weird effect is displayed by its varied interactions with the anti-fungals. Ketoconazole and Fluconazole are both Part of SICKFACES and are enzyme inhibitors…
However,Phenytoins own levels are INCREASED by fluconazole and miconazole= phenytoin TOXICTY
Phenytoin itself INCREASES the levels of Ketoconazole and itraconazole
What is the interaction between PHENYTOIN and AMIODARONE?
Amiodarone inhibits the metabolism of Phenytoin:Phenytoin concentration increases
Phenytoin is metabolised by CYP450 enzymes. Some of the enzyme inhibitors can therefore increase [Phenytoin]. Which ones?
Isoniazid Cimetidine Fluconazole Chloramphenicol ErythromycinSulfamethoxazole Ciprofloxaxin Omeprazole Metronidazole
What electrolyte disturbance can Theophylline cause?
HypokaleamiaPatients may also be on salbutamol (/ beta 2 agonists) for their asthma- can also cause hypokaleamia
Severe asthma patients- monitor K+ as may alsobe on corticosteroids- can cause hypokaleamia
Diuretics- hypokaleamia
Monitor plasma Potassium in severe asthma/ with theophylline therapy.
What is Theophylline? How does it work?
It is a xanthine Same family as CaffeineIt is a broncho dilator
Theophylline is used in Chronic Asthma Therapy only, usually orally as an MR prep.When is Theophylline used in Asthma therapy?
Can be used at step 3 or 4 of the asthma pathwayStep 3: as an add-on therapy to ICS/ LABAStep 4: As a regular bronchodilator (6 week trial)
Signs of Theophylline toxicity?Hint: same family as caffeine
- Vomiting
- Restlessness
- Agitation
- Dilated Pupils
- Sinus tachycardia (palpitations)
- Hyperglyceamia
- Severe HYPOKALEAMIA
- Hallucinations
Severe toxicity: convulsions, arrhythmias, throwing up blood
How do we treat theophylline toxicity?
Treatment: Repeated activated charcoal, ondansetron for vomitting, potassium chloride
Short acting beta-blocker (e.g. Esmolol) may reverse severe tachycardia, hypokalemaia and hyperglyceamia.
The plasma concentration of theophylline is increased in ….3…. conditions?
Heart Failure
Hepatic impairment
RespiratoryViral infections
So watch out for signs of toxicity (plasma conc rising above 20mg/ L)
What two social activities can DECREASE theophylline levels?
SMOKING
Alcohol consumption
Why is it important to ensure the same BRAND of theophylline is maintained?
Rate of absorption from different modified release preparations can change between brandsThe brands have different dosing regimesBrands: Uniphyllin Continus®, Slo-phyllin®, Nuelin SA®
How can Slo-phyllin (theophylline) capsules be taken?
Swallow whole with water OR granules can be sprinkled onto yoghurt/ soft food and swallowed without chewing
How is theophylline metabolised?
HEPATICALLYtherefore reduce dose in liver impairment!
What are the three E’s that Theophylline should be used in caution with?
Epilepsy- reduced seizure threshold (Hence interaction with Quinolones!) Elderly-Increased plasma theophylline conc- maybe due to reduced Liver function
Elevated BP- Hypertension, also hyperthyroidism
Theraputic range of Carbamazepine?
4 - 12 mg / L
Gentamicin- multiple daily dose regimen- one hour peak serum concentration?And for endocarditis?
NB: For once-daily: consult local guidelines
5 - 10 mg / L
Endocarditis: 3 - 5 mg/ L
Gentamicin-pre-dose trough concentration?And for endocarditis?
< 2 mg/ L
Endocarditis: < 1 mg/ L
For Vancomycin monitoring, we just take Pre-dose Trough levels.What should this be?Different for endocarditis?When should this be taken?
Trough level: 10 - 15 mg/ L
Endocarditis: Aim higher for Vancomycin (its lower for Gentamicin): 15- 20 mg/L
Take this after 3rd or 4th dose
if renal function normal, 30 MINUTES before next dose is due
When should plasma theophylline concentration be measured after starting oral treatment?How many hours after a dose should a blood sample be taken?
5 days after starting
Take blood sample 4 - 6 hours after an oral dose of a Modified release preparation
Why is it important for prescribers to specify the brand of aminophyllin or theophylline MR tablets?What can be done for smokers on aminophylline?
The rate of absorption from MR preparations can differ between brandsSpecific brand of aminophylline (phyllocontin continus) forte tablets are for smokers (smoking induces metabolism of aminophylline/ theophylline)
What are the side effects of Theophylline?
DiarrhoeaConvulsions- lowers seizure thresholdArrythmiasHeadacheInsomniaVomitting
We know that sodium effects Lithium levels. How does it effect lithium levels?!
Lithium will follow sodiums movement: So if plasma sodium is low, renal reabsorption of sodium occurs (as the sodium ions move from high to low concentration) and lithium follows,
so lithium levels RISE- lithium toxicityIf plasma sodium is high: more sodium excreted/ less reabsorption- lithium follows and lithium level decreases- subtherapeutic
This is why we say keep your salt intake stable- dont increase or decrease it!
What is Carbimazole used for?
HyperthyroidismReport any sore throat, ulcers, fever, malaise, bleeding with Carbimazole
What is the difference between:<em>Agranulocytosis</em><em>Thrombocytopenia</em><em>Blood Dyscrasias</em>
Agranulocytosis: WBC’s go down; sore throat, fever, malaise all symptoms
Thrombocytopenia: Platelets go down: blood very thin: unexplained bleeding/ bruising. Can be from Heparins
Blood Dyscrasias:Entire blood profile goes down; symptoms of both of the above, this is why we report both sets of symptoms with some drugs
What is the loading dose of Amiodarone?
200mg TDS for 7 days200mg BDfor 7 daysThen 200mg OD from there on (maintenance)
Why load? Long half life (50 days)means it would take ages to reach therapeutic levels. Also meansinteractions can still occur months after stopping.
Symptoms of Aspirin Overdose (5)
Tinnitus
Hyperventilation
Deafness
Vasodilation
Sweating
Why is rifampicin considered High Risk do you think?(Rifampicin is one of the TB drugs)
Many interactions- as it is an enzyme Inducer,
it induces ALL of the CYP enzymes: decreases efficacy of COC’s
HEPATOTOXIC : Monitor LFTs, counsel on liver toxicity signs,stop if: Persistent Nausea Vomiting Malaise Jaundice
Also colours urine/ body fluids/ soft contact lenses red/ orange
What monitoring is needed with Rifampicin?
LFT’s before starting- continue to monitor if on prolonged therapyRenal function before startingFBC if on prolonged therapy
Which class of antibiotics do we need to use with caution in EPILEPTICS?
Quinolones- Ciprofloxacin, Levofloxacin
These lower seizure threshold!
Particularly if used with theophylline
Why do we need to check albumin levels with warfarin?
Warfarin is highly protein bound to albumin- if this is low there may be issues transporting it round the bodyneed to monitor both renal and liver function with warfarin
People stable on warfarin- how often is INR checked?
Every 3 monthsUnless changes in clinical status occur e.g. diarrhoeaand vomitting
What (quite unpleasant)side effects are associated with Amiodarone use, what signs should patients look out for? (7)
Nausea and vomitting and taste disurbance Thyroid function- Hypo and Hyperthyroidism through action of IODINE in the drug
Phototoxic skin reactions: burning sensation, erythema, slate grey skin discolouration
Pulmonary toxicity- persisitent SOB/ Cough Tremor
peripheral neuropathy- numbness in hands and feet
Corneal microdepositis in eyes- dazzled by headlights- common SE: this is reversibleonce drug stopped
Liver toxicity: Jaundice
What is the half life of amiodarone
approx 40-50 days
What 5 things needmonitoring at baselinewith Amiodarone?
LFT’s- Hepatotoxicity a risk
THYROID FUNCTION- hyper/hypothyroidism
Serum Potassium!!!! before starting
Chest X-ray- pulmonary toxicity
ECG with IV use
LFT’s and TFT’s need monitoring after 6 months too!
What is Amiodarone used for?
Treatment of Both supraventricular and ventricularArrhythmias, Ventricular fibrilation, ventricular tachycardia
Usually used when other drugs failed as quite a nasty drug
Rhythm control as part of pharmacological cardioversion in AF.
Methotrexate inhibits dihydrofolate reductase and therefore reduces folate in the body. What drug has to be given with methotrexate as supplementation to prevent its nasty side effects, and when?
For prevention of methotrexate induced horrible side effects in Chron’s/ RA: Folic acid 5mg ONCE WEEKLY- dose to be taken on a DIFFERENT DAY to methotrexate
Methotrexate may lead to blood disorders (most significantly neutropenia and increased infection risk)through BONE MARROW SUPPRESSION. Its anti- folate propertied may explain how it suppresses bone marrow…
Bone marrow is where the body creates new cells. Cell division requires folate in order to occur.Since folate deficiency limits cell division, erythropoiesis, production ofred blood cells, WBC, neutrophils etc is suppressed in the bone marrow when methotrexate is taken as it is anti- folate.
This is the same story as with Trimethoprim/Co- trimoxazole and Phenytoinas these are also anti-folate-
Avoid use together!Production of RBC’s beinghindered also leads tomegaloblastic anemia, which is characterized by large immature red blood cells that cannot divide.
What monitoring does Methotrexate require?
Renal function
LFT’s
FBC (due to blood disorder risk)
These should be 1-2 weekly until dose stabilised then 2-3 monthly thereafter
Exclude pregnancy- pregnancy test before starting?Avoid in hepatic impairment and reduce dose in renal impairment unless severe- then avoid.
What is Methotrexate used for?
Main use in:Rhumatoid ArthritisSevere Chron’s (Inflammatory Bowel Disease)Severe PsoriasisIt is cytotoxic- stops cell division- part of chemotherapy
What are the Methotrexate warning signs
Blood disorder: Bone marrow suppression- sore throat, ulcers, fever, rash
Liver toxicity-N&V, abdominal pain,dark urine,Jaundice
Gastro-intestinal toxcitiy: stomatitis, GI upset (sore mouth first symptom)
Pulmonary Toxicity- persistentSOB, cough
PREGNANCY & Breastfeeding- its anti-folate so avoid!! -contraception needed during treatment and for 3 months after stopping
WITHDRAW TREATMENT IF ANY OF THESE OCCUR>
What OTC med’s can increase the risk of Methotrexate toxicity?
NSAIDS/ ASPIRIN !!Reduce methotrexate excretion in kidneyAs do penicillins!
A patient comes in complaining of mouth sores, they think it may be cold sores. After further questioning you find out they are on Methotrexate. What do you do?
Advise they seek medical attention ASAP
Mouth sores may be a sign of stomatitis (inflammation of mouth) which is the first sign of Gastro-intestinal toxicity associated with Methotrexate!
A patient asks for some Lozenges as they are experiencing a very sore throat. You find out they are on Methotrexate. What do you do?
Seek medical attention ASAP
Sore throat is most common side of blood disorders with Methotrexate
Patients can sometimes overdose on Methotrexate as they get confused that it is Just once weekly dosing. What are the symptoms? what is methotrexate toxicity treated with?
Renal impairmentLiver impairmentHeadache, seizures, coma
Treatment: FOLINIC ACID- rescues normalcells from methotrexate effects
What happens when Baclofen (used for pain of muscle spasms in palliative care/ trauma) issuddenly withdrawn? What if itis given with ACE inhibitors or Beta blockers?
Suddenly withdrawn: hyperactivity, hyperthermia, hallucinations, convulsionsEnhanced Hypotensive effects with ACEi/ Beta blockers
Which NOAC is contra-indicated in patients with a Prosthetic valve?
DABIGATRAN
which OTC medication can affect the absoprtion of anti epileptics
ORLISTAT (Alli)
What needs monitoring with Vancomycin (4)?
Full blood count: can cause both LOW PLATELETS and LOW NEUTROPHILS (Neutropenia)
Renal function- Nephrotoxic- Urinalysis, CrCl used for dosing
Hearing function in the elderly
Plasma concentration
What needs monitoring with Gentamicin?
Renal function
Hearing function
Plasma concentration
NB: differs to vancomycin as do not need to monitor FBC- does not cause neutropenia/ low platelets
Which antihypertensive drugs require the SAME BRAND to be maintained?
Diltiazem
Nefedipine(Both CCB’s)
Which CCB <strong>cannot be used </strong>in both Supraventricular and Ventricular arrhythmias?
VERAPAMIL Used for Supraventricular only
verapamil NOT to be used in ventricular Arrhythmias
Ciclosporin (an immunosuppressant drug) has many interactions. This is because it is toxic to many organs, so any drug effecting each of those organs will be contra-indicated with ciclosporin use. What toxicitys can it cause (5)?
Neurotoxicity (CNS- tremor, convulsions, encephalopathy)
Liver toxicity (jaundice, N&V, abdo pain, dark urine)]
Nephrotoxicity (kidney)
Blood toxicity/ disorders (fever, sore throat, ulcers, bleeding)
Hypertension- BP needs monitoring regularly
Patient should report any of these signs
What type of vaccines are Ciclosporin and Tacrolimus Contra-indicated with?
Live vaccines - Live vaccines can, in some situations, cause severe or fatal infections in immunosuppressed individuals due to extensive replication of the vaccine strain that the immune system cannot fight off.
Same goes with high dose corticosteroids: these can suppress the immune system so avoid live vaccines
What should patients on corticosteroids be told with regards to chickenpox/ measels?
If they have not have these before, avoid any exposure to anyone with these as they can contract very severe forms of these if they do.
Why is an eye exam needed with corticosteroid use?
Risk of eye problems:Glaucoma- look for intraocular pressureCorneal thinning
What drugs can increase the risk of someone developing gout (build up of uric acid)?
Diuretics– clears excess fluid out of body butthe remaining fluid is more concentrated;increases the risk of developing the crystals that causegout
Beta-blockersand ACE inhibitors
low-dose aspirin– used to reduce the risk ofblood clots
niacin–used to treat high cholesterol
ciclosporin– used to treat conditions such aspsoriasis</p>
What are the symptoms of gout?What are the dietary risk factors of gout?
Build up of uric acid causing: suddenattack ofsevere painin one or morejoints, typically big toe. joint feeling hot and very tender,swellingin and around the affected joint
Dietary risk factors:high in meat and seafood and high in beverages sweetened with fructosepromotes higher levels of uric acid, also alcohol.
Phospohorus can help cure gout: Banana is a rich source of phosphorus.
What is the main symptom of Hypokaleamia?What drugs can cause hypokaleamia?
Ventricular Arrhythmias (Hyperkaleamia can also cause arrhythmias!)
Thiazide, thiazide-like and Loop diuretics
Sotalol
Salbutamol
Amisulpiride
Atomoxetine (used for ADHD)
Can you inject potassium chloride 20% w/v straight?
No- must be diluted first with sodium chloride 0.9%
Must be given by slow infusionMonitor ECG- rapid infusion would be toxic to heart and arrhythmias occur
Need to the patient is weeing enough- contraindicated in anuria (absence of urination) as potassium would build up
What could black stools or coffee groung vomit be suggestive of with NSAIDs? What about Iron deficient aneamia?
GI bleeding
What are the following indicative of with NSAID therapy?
Unexplained weight loss
difficulty swallowing
nausea or vomiting
bloating
burping or acid reflux- recent onset dyspepsia
Peptic ulcer
What could swollen ankles indicated with NSAID therapy?
Kidney failure
Which NSAID is now contra-indicated in patients with a cardiac disease history/ risk of CV disease?
Diclofenac The new treatment advice applies to systemic formulations (ie, tablets, capsules, suppositories, and injection available both on prescription and via a pharmacy, P);
it does not apply to topical (ie, gel or cream) formulations of diclofenac.
What electrolyte disturbance could NSAIDs effectively cause?
NSAIDs can damage the kidneys (AKI)
This can in turn lead to HYPERKALEAMIA.
A dose increase for an opioid should be no more than __% of the last dose
No more than 50%
Due to risk of overdose
Aside from their use in pain, what else can strong Opioids be used for?
Relief of breathlessness in palliative careRelief of breathlessness and anxiety in acute pulmonary oedema (alongside oxygen, furosemide, nitrates)- Myocardial infarctionBut do not give them in respiratory failure!Suprising when they can cause respiratory depression! This is because they reduce cardiac work and oxygen demand- hence their use in Myocardial Infarction.
What side effects do opioids have on the skin?
They cause histamine release- this can cause
ITCHING and urticaria (hives/ nettle rash), also sweating
Biliary colicis atype of pain related to the gallbladder that occurs when a gallstone obstructs the cystic duct and the gallbladder contracts. Should we use opioids for this pain?
No- opioids can worsen the pain due to sphincter spasm
How is chronic pain usually managed with strong opioids?
Oral route first: Start with an immediate release solution such as OramorphThen once optimal dose found-
switch to modified release (MST Continus- administered BD [12 hourly])For breakthrough pain, immediate release (Oramorph) morphine at a dose of 1/6 the usual.
Why must codeine/ dihydrocodeine never be given via the IV route?
Can cause a severe reaction similar to anaphylaxis (but not allergy based)
Which opioid should be avoided in epileptics?
Tramadol: it lowers the seizure thresholdAvoid with other drugs that lower seizure threshold: SSRI’s, TCA’s, quinolones, theophylline
What is heaviness in the centre of the chest likely to indicate?
Heart attack
How should oral antiplatelets be administered?
With or just after food (to protect stomach)
Except for Dipyridamole: 30 to 60 mins before food
Why is Tacrolimus such a high risk drug? What can it cause?Hint: Similar to Ciclosporin. Both toxic to many organs
Neurotoxicity (CNS)- tremor, headacheNephrotoxicityEye disorders (ciclosporin not toxic to eyes)
Blood disorders- report fever, sore throat, ulcers etcSkin disorders- rashHyperglycaemiaLiver toxicity
What dietary substances should patients on Tacrolimus / Ciclosporin avoid?
Avoid a diet high in Potassium (as these can BOTH cause Hyperkaleamia)
Avoid grapefruit juice- Increases plasma concentrations of these as its an enzyme inhibitor
What drugs can cause Hyperkaleamia?
Ace inhibitors/ ARBsPotassium sparing diuretics (spironolactone + eplerenone)Ciclosporin and Tacrolimus (immunosuppressants)NSAIDs
What do we use to treat hyperkaleamia?
Calcium gluconate The priority is to stabilise the heart: do not want it to arrest due to fatal cardiac arrhythmias
Then sort out hyperkaleamis: IV insulin or salbutamol as temporary measures to drive K+ back into cells
If its severe- use Heamodialysis: Why not use diuretics, as these cause hypokaleamia too?- as diuretics will effect fluid balance. do not want to put any more strain on the heart.
<p>What should a patient do if they miss a warfarin dose?</p>
Do not double up!If later that evening- take dose. If next day- skip dose
Why are beta blockers used with caution in diabetes?
Can mask hypoglyceamia:beta blockers blunt the of adrenalin: if someone becomes hypoglycemia adrenalin doesnt kick in and they dont get warning symptoms.
Sweating is the only symptom that still shows.
Canalso prevent adrenalin from stimulating the liver to make glucose, and therefore may make the hypoglycemia more severe
Why are beta blockers cautioned in asthma and COPD?
Risk of bronchospasm If absolutely need one: choose a cardio selective BB like Bisoprolol
Why do we get a dry cough with Ace inhibitors and not ARB’s?
ARB’s do not increase bradykinin levels, because they do not inhibit ACE
Why are NSAID’s cautioned in asthma, what can they cause?
Bronchospasm- does not happen to every asthmatic.
Which diuretics can exacerbate diabetes?
Thiazides (most likely)
Loop diuretics: Due to hyperglyceamia side effect!
What do we need to monitor with diurectic use?
Electrolytes:Na +K +Mg +
Renal function
Uric acid levels (risk of gout)
Hyperglyceamia- can exacerbate diabetes
Hypotension- BP lowering effects
When do we use simvastatin at a max dose of 10mg?
With fibrate use in combo: massive risk of myopathy+ Bezafibrate+ Ciprfibrate
Do not use gemfibrozil at all- risk of Rhabdomylosis too great
Which oral antidiabetic carries the least risk of Hypoglyceamia?
Metformin
What vitamin deficiency can Metformin cause?
Vitamin B12 (cobalamin) Symptoms of deficiency: neuropathy (numbness, pain, or tingling in hands or feet)
Anaemia- extreme tiredness (fatigue)
lack of energy (lethargy)
breathlessness
pale skin
Ace inhibitors have some protective and some negative effects on the Kidneys. When are they contra- indicated?
Bilateral Renal artery stenosis - they will make it progress into renal failure
Less effect on Unilateral renal artery stenosis
Best to avoid in patients with known or suspected RENOVASCULAR disease
<p>What is the max daily dose of Codeine?</p>
<p>How long must intervals between doses be?</p>
<p>,Max number of days OTC?</p>
240mg daiy
6 hour intervals
3 days OTC
What drug causes ‘Purple glove syndrome’ skin diseasein which the extremities becomeswollen, discoloured and painful
Phenytoin if given IV
What are the EPSEs?
Extrapyramidal Side Effects (EPSEs)
Akathisia: Restlessness, inability to sit still.
Dystonia: Muscle spasms, twisting motions.
Parkinsonism: Tremors, stiffness, slow movement.
Tardive Dyskinesia: Involuntary facial and body movements.
Bradykinesia: Slowness of movement.
Tremor: Shaking, typically of hands.
Rigidity: Muscle stiffness, resistance to movement.
