PSA/pharmacology Flashcards
What is an example of a GLP- 1 mimetic and how do they work?
Exanatide
Works by Reducing gastric emptying
Decreasing appetite
And acting on the pancreas to decrease glucagon and increase insulin
What is an example of DPP4 inhibitor and how does it work?
So the DPP-4 enzyme normally acts on GLP1 mimetic and breaks them down, DPP4 inhibitors like SITAGLIPTIN prevents the breakdown of GLP-1
How do SGLT-2 work?
They cause glucose to be lost through the kidney
Campagliflozin, empagliflozin, dapagliflozin
What are the side effects of SGLT-2 inhibitors (gliflozins)
Glucoseuria
Increase in UTIs and cadida (thrush)
WEIGHT LOSS - osmotic diuresis, water is drawn into the urine through osmosis
Dehydration
DKA= rare complication
What is a side effect of gliclazide (sulfonylurea)?
Hypoglycaemia
WEIGHT GAIN
What are the two regimes for insulin?
Basal bolus
This mimics normal and involves long acting at night and fast acting
Twice daily
This involves intermediate and short acting
What should you do to someones insulin
If
A) they are hyperglycaemia
B) they are hypoglycaemic
A) increase insulin dose by 10%
B) decrease insulin dose by 20%
What are the common reasons why hypoglycaemia occurs?
Taking too much insulin Not having regular meals/missing meals Not eating enough carbs/overestimating the amount you have eat Stress Too much alcohol or drinking Physical activity Hot weather Recreational drugs
What are the symptoms hypoglycaemic pts experience?
Tingling Feeling hot and sweaty Light headed Blurred vision Hunger Dizziness Fast pulse or palpitations Trembling or shakiness Anxiety or irritability Disorientated Lack of concentration Change in personality or irritability Confusion or vagueness
How do you treat hypoglycaemia if the pt is concious?
15-20g rapid acting carbs- like 200ml orange juice, this can be repeated up to 3 times!
If 15-20g of quick acting carbs is given and this doesnt work, then what can be done next?
IM glucagon if no improvement after ten mins then move to IV
IV 15-20g over 15 mins
20% glucose (75-100ml) or 10% (150-200ml)
How do you treat DKA?
Identify if need for fluid rescucitation (SBP<90mmHg)
Fixed rate quick acting IV insulin ie actrapid 0.1units/kg/hr
Start/continue s/c long acting insulin
Glucose 10% once BM<14
Monitor K+
Identify cause
Why is pioglitazone thought to be a ‘dirty drug’?
Weigh gain
Bladder cancer
Fracture risk
How does COCP work?
Inhibits ovulation
Thins endometrium
What are the contraindications of COCP?
HTN Smoking BMI>35 Migraine VTE history
What are the side effects of COCP?
Increased risk of breast cancer
Increased risk of cervical cancer
Decreased risk of endometrial cancer
Decreased risk of ovarian cancer
When can you start COCP after pregnancy?
6 weeks
How does POP work?
Thins endometrium and thickens cervical mucus
What is the contraindication of POP?
PV bleeding
What are the side effects of POP?
Irregular bleeding
Nausea
Sore breasts
What are the side effects of ACE-I?
Hyperkalaemia
Cough
Angioedema
First dose hypotension
What are the cautions and comtraidications for ACE- I?
Pregnancy and breastfeeding
- avoid
Reno vascular disease - may result in renal impairment
Aortic stenosis- may result in hypotension
Hereditary or idiopathic angioedema
Specialist advice should be sought before starting ACE I in patients with a K+ > or equal to 5mmol/L
What does ACE- I interact woth?
Patients recieving high dose diuretic therapy (more than 80mg of furosemide a day) significantly increases the risk of hypotension
What are the monitoring requirements for ACE- I?
Urea and electrolytes should be checked before treatment is initiated and after increasing the dose
What is tamsulosin?
What side effects does it cause?
An alpha 1 antagonist used to treat BPH
Postural hypotension, drowsiness, dyspnoea, cough
What is doxazosin?
Used to treat BPH
Causes postural hypotension
What drugs cause gynaecomastia?
spironolactone (most common drug cause) cimetidine digoxin cannabis finasteride GnRH agonists e.g. goserelin, buserelin oestrogens, anabolic steroids
What are the side effects of sodium valproate?
Increased appetite Weight gain Alopecia- regrowth may be curly P450 enzyme inhibitor (may affect warfarin INR- INR increases) Ataxia Tremor Hepatitis Pancreatitis Thrombocytopaenia Teratogenic (neural tube defects)
What are the side effects of carbamazepine?
P450 enzyme inducer dizziness and ataxia drowsiness leucopenia and agranulocytosis syndrome of inappropriate ADH secretion visual disturbances (especially diplopia)
What are the side effects of lamotrigine?
Steven Johnson syndrome
What are the side effects of phenytoin?
P450 enzyme inducer Dizziness and ataxia Drowsiness Gingival hyperplasia Hirsutism Coarsening of facial features Megaloblastic anaemia Peripheral neuropathy Enhanced vit D metabolism causing osteomalacia Lymphadenopathy
Why do you use isosorbide mononitrate assymetrically (morning and lunch)?
Isosorbide mononitrate is a nitrate drug used in the management of angina pectoris. It is a vasodilator that acts on both arteries and veins. Venous vasodilation reduces venous return to the heart and therefore preload which reduces the oxygen requirement of the myocardium. The arterial vasodilation results in a reduction in systemic vascular resistance and improved coronary blood flow. Nitrate tolerance is a phenomenon whereby patients experience reduced therapeutic effects due to the continuous use of nitrate drugs. This can be overcome by ensuring the patient’s blood-nitrate concentrations fall to a low level for 4-12 hours of the day. This is achieved by ‘asymmetric dosing’ which means giving a dose in the morning and a dose in the mid-afternoon, rather than giving it 12-hourly. This means the patient will have a period of time overnight where there is a lower level of nitrates in their blood, which should minimise tolerance. Asymmetric dosing is only a requirement for the standard-release formulation. Modified-release preparations are available that are given once daily.
What are the drugs which are enzyme inducers?
What are the drugs which are enzymes inhibitors?
SICKFACES.COM Sodium valproate Isoniazid Cimetidine Ketoconazole Fluconazole Alcohol Clarithromycin Erythromycin Sulphonamides Ciprofloxacin Omeprazole Metronidazole Grapefruit juice
What drugs are used as enzyme inducers?
SSSCRAPG Sulphonylureas St jogns wort Smoking CARBAMAZEPINE Rifampicin Alcohol (chronic use) Phenobarbital Phenytoin Griseofulvin
What medications should be stopped for surgery?
It can be remembered by ‘ILACKOP’
Insulin (varies between hospitals)
Lithium- day before
Anticoags/antiplatelets- variable and can sometimes continue during surgery
When are warfarin, aspirin and heparin contraindicated?
In patients who are bleeding, at risk of bleeding or have suspected bleeding.
Prophylactic heparin is contraindicated in acute ischaemic stroke due to the risk of bleeding into the stroke. Also important to remember that erythromycin can increase warfarin’s effect (and hence prothrombin time0 and INR despite stable dose)
When are steroids contraindicated?
STEROIDS... S- Stomach ulcer T- thin skin E- Edema R- Right and left heart failure O- Osteoporosis I- Infection D- Diabetes (steroids raise blood glucose) S- Cushings SYNDROME
What are the contraindications for NSAIDS?
N= No urine output (renal failure) S= Systolic dysfunction A= Asthma I= Indigestion D= Distorted clotting
What are the side effects of antihypertensives?
Hypotension (including postural) that may result from all groups of antihypertensives
Bradycardia may occur with some CCBS and beta blockers
Electrolyte disturbance occurs with ACE-I and diuretics
Individual drugs have specific side effects…….
- ACE-I= dry cough
- Beta blockers= wheeze in asthmatics and also worsening of acute heart failure
- CCBS= peripheral oedema and flushing
- Diuretics can cause renal failure, loop diuretics (Furosemide) can also cause gout, K+ sparing diuretics can cause gynaecomastia.
How should you go about prescribing fluids?
First assess the patient
Secondly look at the chart
Thirdly look at the bloods- U and ES.
What is a good choice of antiemetics?
Cyclizine
When should you avoid Metaclopramide?
Metaclopramide is a pro kinetic and a dopamine receptor antagonist, therefore avoid in bowel obstruction, avoid in parkinsons
It can cause acute dystonia
What are anticholinergics used for and what are the side effects?
They work by blocking the muscarinic receptors from the neurotransmitter acetylcholine, this is released from the cholinergic nerve endings in the airways.
They inhibit the parasympathetic nervous system
Side effects= confusion/drowsiness, dry skin, constipation, urinary retention, dry mouth, palpitations, blurred vision, increased intraocular pressure
When should you avoid cyclizine?
In heart failure as it can cause fluid retention
What can be used in painful diabetic neuropathy?
Duloxetine
What analgesia should be used for; a) no pain b) mild pain c) severe pain ???
a) No regular but can prescribe paracetamol PRN
b) Paracetamol regularly, codeine 30mg up to 6 hourly oral
c) Co-codamol if severe pain, 2 tablets 6 hourly oral or morphine sulfate as required
Which dopamine receptor antagonist is more likely to be used as an anti emetic in parkinsons- domperidone or metoclopramide?
Domperidone, despite them both being dopamine antagonists, metoclopramide crosses the blood brain barrier and so exacerbated parkinsonian symptoms by acting on central dopamine receptors
domperidone does not cross the BBB so is safer to use in Parkinson’s disease
How do ACE- I cause hyperkalaemia?
They reduce the potassium excretion in the kidneys due to reduction of production of aldosterone
How does ibuprofen lead to inflammation and ulceration?
Ibuprofen inhibits prostaglandin synthesis needed for gastric mucosal protection from acid, it is therefore at risk of influencing inflammation and ulceration
How do steroids predispose to gastric ulceration?
They inhibit gastric epithelial renewal
What antibiotic should not be used alongside methotrexate and why?
Trimethoprim, as they are both folate antagonists
This can lead to bone marrow toxicity- pancytopaenia and neutropenic sepsis
When should you withhold methotrexate?
If patient is septic
What should patients on warfarin with an INR of >2 not be given?
They shouldn’t be given any prophylactic heparin as it increases the risk unnecessarily
What is the usual route for insulin to be administered?
Normally sub cut, incept in variable rate where it is IV.
What is the most worrying side effect of clozapine?
Clozapine is an antipsychotic (Atypical) and the most worrying side effects (for which all patients are monitored with at least monthly blood tests) is agranulocytosis, resulting in neutropoenia
When there is agranulocytosis and neutropoenia, it requires immediate cessation of the drug and referral to haematology
What are the most important results of a FBC to look at?
Hb
WCC
Platelets
What are the most common causes of neutrophilia (high neutrophils)?
Bacterial infection
Steroids
Tissue damage (inflammation, infarct and malignancy)
What are the most common causes of neutropaenia?
Viral infection
Chemotherapy or radiotherapy
Clozapine (Antipsychotic)
Carbimazole (antithyroid)
What are the causes of high lymphocytes (lymphocytosis)
Viral infection
Lymphoma
Chronic lymphocytic leukaemia
What is the first thing you should assess if someone has deranged sodium function?
Their fluid status
What are the causes of hypernatraemia?
3DS
Dehydration
Drugs
Drips (too much IV saline)
What are the causes of microcytic anaemia (low Hb) ?
TAILS Thalassaemia Anaemia of chronic disease IRON DEFICIENCY ANAEMIA Lead poisoning Sideroblastic
What are the causes of normocytic anaemia (Normal MCV)?
Anaemia of chronic disease
Acute blood loss
Haemolytic anaemia
Renal failure (Chronic)