Pharmacology Flashcards
List of Aminoglycosides
- gentamicin
- streptomycin
List of macrolide antibiotics
- Azithromycin.
-Clarithromycin. - erythromycin
List of glycopeptide antibiotics
- Vancomycin
- Dalbavancin
- Oritavancin
List of antihistamines
- diphenhydramine
- ranitidine
List of antihypertensives
- Clonidine
List of calcium Channel Blockers
- nifedipine
- Amlodipine
List of antiplatelets
- Aspirin
- clopidogrel
- ticagrelor
- Apixaban.
- Reteplase
- Dabigatran
- Abciximab
- Tirofiban
List of anticoagulants
- heparin
- LMWH
- warfarin
- apixaban
- dabigatran
- rivaroxaban
- fondaparinux
List of Thiazides
- hydrochlorothiazide (HCTZ)
- indapamide
- chlorthalidone
List of DMARDS
- methotrexate
- sulfasalazine
- infliximab
- adalimumab
- leflunomide
- rituximab
- antimalarials
List of antimalarials
- Doxycycline.
- Atovaquone/proguanil.
- Mefloquine.
- Primaquine.
Drugs which undergo entero-hepatic circulation
- Colchicine
- Phenytoin
- Leflunomide (immunosuppressant)
- tetracycline
St John’s wort (Hypericum perforatum) Medication interactions
HIV medicines
warfarin
digoxin
anticonvulsants
oral contraceptives
triptans
Normal range of lithium
0.8 mmol/L to 1.4 mmol/L
Normal: review every 3 months
Therapeutic dosage of corticoid steroids
Continue same dose on IV
List of diseases that require therapeutic steroid dosage
- COPD
- asthma
- rheumatoid arthritis
List of diseases that require physiologic replacement of steroids
- Addison’s disease
Physiologic replacement of steroids dosage
- for patients receiving physiologic replacement doses of glucocorticoids
(Addison’s disease) - additional 50 mg of
hydrocortisone intraoperatively. This dose should be continued for 48 to 72 hours
postoperatively at an interval of 8 hours in patients undergoing major surgery.
Contraindications to use nitrates
-Systolic blood pressure less than 90 mmHg.
– Heart rate less than 50 beats per minute.
– Heart rate greater than 100 beats per minute.
– Known right ventricular infarction.
– Severe aortic stenosis
Mechanism of action of
sulfonylureas
Stimulates pancreatic beta cells and cause secretion of insulin. it does this by increasing responsiveness of
beta cells to both glucose and non-glucose secretagogues (such as amino acids),
resulting in more insulin being released at all blood glucose concentrations.
Thus, sulfonylureas are useful only in patients with some beta cell
function
Examples of Sulfonylureas
- gliclazide
-glimepiride - glipizide
Mechanism of action of Metformin
Enhances insulin binding to the beta cell insulin receptor
treatment-resistant schizophrenia
- give clozapine
if patients are experiencing sedation, decrease dose and review
Increased dosage of dopamine can cause
Extrapyramidal syndrome
Extrapyramidal syndrome
4 types:
1. Parkinsonism
2. Akathisia
3. Acute Dystonia
5. Tardive Dyskinesia
Patient exhibits symptoms of Extrapyramidal syndrome: most appropriate management?
First approach is to consider a reduction in dopaminergic supplementation, without loss of therapeutic efficacy.
If this cannot be achieved, an alternate medication like amantadine, pergolide
Drugs to avoid in patients with Parkinson’s
strong dopamine antagonists
- Haloperidol
Epileptic drugs on OCP
Epileptic drugs induce liver enzymes and reduce the efficacy of oral contraceptive pills by 40%.
- There is 6% failure rate when low-dose oral contraceptive pills are used in women taking anti-epileptic medications (just like St John’s wort)
- In such situation, **oral contraceptive pills with high oestrogen content **(Microgynon 50) should be used to minimise the risk of “pill failure”
List of epileptic drugs
- phenytoin
- carbamazepine/Oxcarbazepine
- barbiturates
- topiramate
- Primidone
– Valproic acid.
– Gabapentin.
– Levetiracetam.
– Pregabalin.
– Vigabatrin
List of chemotherapeutic drugs
- cyclophosphamide
- ifosfamide
- Adriamycin (doxorubicin)
Non-inducing antiepileptic medication
– Valproic acid.
– Gabapentin.
– Levetiracetam.
– Pregabalin.
– Vigabatrin
antibiotics can produce a clinical disturbance similar to
botulism
Gentamicin prevents the release of acetylcholine from nerve endings like botulinum toxin
- can cause muscle paralysis in high-risk patients.
- Symptoms subside rapidly
as the responsible drug is eliminated
Side effects of Gentamicin
- Nephrotoxicity
- Autotoxicity
- Flaccid paralysis
Contraindications of Gentamicin
- pre-existing disturbance of neuromuscular
transmission - Myasthenia gravis
Contraindications of asthma
- beta blockers
Essential tremor treatment in a patient that has asthma
- Primidone (1st choice)
- low dose benzodiazepines
- Stereotactic thalamotomy and deep brain stimulation on treatment-resistant essential tremors
situations when the patient can continue to take hypnotics
Use of medication for up to 6 months or even years:
1. Patient must be aware of this that he/she is dependent on that specific hypnotic.
2. There is no history of any adverse event or adverse side effect from that
medication.
3. Reduction program has been unsuccessful
Digitalis toxicity in ECG
- ST depression and T wave inversion in V5-6 in a reversed tick pattern.
- Bradycardia
- Prolonged PR
- Shortened QT
- Arrhythmias, especially heart block or bigeminy
Signs of raised intracranial pressure
- vomiting
- bradycardia
- hypertension
- drowsiness
Features of hypertensive encephalopathy
- higher blood pressures
more than 180/120 with an insidious onset - headache
- emesis
- confusion
- restlessness and seizures
Amitriptyline/Amiodarone overdose ECG Changes
(TCA toxicity)
Widening of QRS complex
Prolongation of the PR and QT intervals
Ventricular tachycardia and ventricular fibrillation
Amiodarone overdose ECG Changes
Widening of QRS complex
Prolongation of the PR and QT intervals
Ventricular tachycardia and ventricular fibrillation
common cause of false positive elevation of plasma normetanephrine and norepinephrine level in a patient on pheochromocytoma
- Major depression(45%) TCA
- Congestive cardiac failure
– Panic disorder
TCA side effects
- hyperprolactinemia
Raised INR is between 5-9 without bleeding in a patient receiving warfarin
- cease warfarin
- give vitamin K orally or intramuscularly and check INR within 24 hours
Raised INR is between 5-9 with bleeding in a patient receiving warfarin
- Intracranial bleed
- Retroperitoneal bleed
- Intraocular bleed
- Muscle bleed with compartment syndrome
- Pericardial bleed
- Active bleed with hypotension or 2 g fall in haemoglobin
- urgent prothrominex-VF
- fresh frozen plasma immediately
INR reversal
- No active bleeding: Vitmain k only
- Active bleeding: ProthrombAinex-VF + Vit K
Vitmain K contraindications
anti-phospholipid antibody syndrome
Medication that cause alopecia
- lithium (12-19%)
- sodium valproate
- carbamazepine
- phenytoin
How long does vitamin K1 takes to have a therapeutic effect?
IV: 6–8 hours
oral: withing 24 hours
never do IM (haematoma, bleeding)
Earliest sign of dose-related toxicity of
carbamazepine
Diplopia within 60 minutes after the morning dose
INR greater than
therapeutic range but
less than 4.5 and
NO bleeding
- Reduce or withhold next dose of warfarin based on sensitivity risk factors
- Resume lower dose of warfarin once INR approaches therapeutic range. If INR is only minimally above therapeutic range (i.e. by 10%) dose reduction is generally not necessary
INR 4.5–10 and
NO bleeding
- Cease warfarin. Consider reasons for elevated INR and patient specific factors. Vitamin K is usually not required.
If bleeding risk high* give vitamin K#
1-2 mg orally or 0.5–1 mg IV. - Check INR within 24 hours. Resume lower dose of warfarin once INR approaches therapeutic range
INR greater than 10
and
NO bleeding
Cease warfarin. Give vitamin K#3-5 mg orally (the higher
dose may lead to difficult re-warfarinisation) or 0.5-1 mg IV. If bleeding risk is high*, consider ProthrombinexTM -VF 15-30 units/kg.
- Check INR in 12 to 24 hours and continue to monitor every one to two days over the following week.
- Resume lower dose of warfarin once INR approaches therapeutic range
INR greater than or
equal to 1.5 with life-threatening (critical
organ) bleeding
- Cease warfarin. Give vitamin K#
5-10 mg IV,
ProthrombinexTM -VF 50 units/kg and FFP 150-300 mL. If ProthrombinexTM
-VF is unavailable, increase FFP dose to
15 mL/kg. - Assess INR frequently until clinically stable
INR greater than or
equal to 2 with
clinically significant
bleeding (not life threatening)
- Cease warfarin. Give vitamin K#
5-10 mg IV and
ProthrombinexTM-VF 35-50 units/kg. If prothrombinexTM-VF is unavailable, give FFP 15 mL/kg. - Assess INR frequently until clinically stable
Any INR with minor
bleeding
Omit warfarin. Repeat INR the following day and adjust warfarin dose to maintain INR in target therapeutic range.
If bleeding risk is high* or INR greater than 4.5, consider vitamin K#1-2 mg orally or 0.5-1 mg IV.
Contraindications to donepezil
-Gastrointestinal or ureteric obstruction.
-Active peptic ulcer.
-Heart block.
-Bradyarrhythmias (sick sinus syndrome).
-COPD
-Parkinson’s disease
NOTE: critically important to do an electrocardiography to rule out any heart block or bradycardia
raloxifene decreases the incidence of
vertebral fractures
raloxifene increases the incidence of
hot flushes
If one osteoporosis treatment isnt’ working, what would be the next appropriate step?
If the original treatment dose is already at its peak, then next thing would be to cease original treatment and start a new one
Medication that could result in a tendon lesion in males over 40 years
fluoroquinolone (ciprofloxacin)
Contraindications of warfarin
– Active bleeding.
– Uncontrolled hypertension.
– History of intracranial bleeding.
– Liver disease with impaired synthetic functions.
– Pregnancy
Acute side-effects of corticosteroids
Hyperglycaemia
hypertension
fluid
retention
myopathy
psychological disturbances
Which medication antagonise the effect of the donepezil?
Drugs with anticholinergic activity:
-amitriptyline
-promethazine
-oxybutynin
Effects of adenosine
-treatment of choice for paroxysmal supraventricular tachycardia
- blocks transmission through AV nodes
- short half life of 10 to 15 seconds (given as rapid
intravenous bolus followed by a saline flush)
- contraindicated in patients with asthma
Unfractionated heparin effect reversal
Protamine sulphate
- Fresh frozen plasma if active bleeding
NSAID’s during pregnancy
Safe up to 32 weeks
After 32 weeks can cause:
-Premature closure of the fetal ductus arteriosus.
-Delay labour and birth.
-Oligohydramnios via an effect on fetal renal function.
Osteonecrosis of the jaw cause
High doses of intravenous bisphosphonates (zoledronic acid)
bisphosphonates contraindications
-Oesophageal stricture.
-Oesophagal achalasia.
-Inability to remain upright for at least 30 minutes.
-Renal failure with creatinine clearance below 35 ml/minute.
-Hypocalcaemia.
-Osteonecrosis of the jaw from chemotherapy, radiotherapy
Side effects of TCA
1-Dry mouth.
2-Sedation.
3-Confusion.
4-Delirium.
5-Urinary retention.
6.Glaucoma.
7-Tremors
8-Weight gain.
9-Postural hypotension.
10-Sexual dysfunction.
11-Lowered seizure threshold.
Factors that increase the clearance of theophylline
ethanol
smoking
high protein
barbecued meat
low carbohydrate diet
Alcohol/Opiate abuse medication
- Naltrexone (substitute for methadone)
Naltrexone contraindications
- Patients receiving opioid analgesics.
- Patients currently dependent on opioids since an acute withdrawal syndrome may
ensue. - Patients in acute opioid withdrawal.
- Any individual with acute hepatitis or liver failure
Factors that increase the risk of bleeding during warfarin therapy
- Diabetes mellitus.
– Acute or chronic alcohol abuse. This is correct response in this situation.
– Increasing age especially if more than 75 years.
– Poor drug adherence.
– Liver disease
– Prior haemorrhagic stroke.
– Chronic kidney disease.
– The presence of bleeding lesion (gastrointestinal bleed).
– The presence of malignancy
Medication that can increase warfarin’s anticoagulant effect and risk of
bleeding
Fibrates (gemfibrozil)
Bosentan mechanism of action
dual endothelin-receptor antagonist of endothelin-1 at the endothelin-A and
endothelin-B receptors
PPI mechanism of action
Irreversible blockade of hydrogen (H )-potassium (K ) ATPase
PPI complications
- Decreased vitamin B-12 absorption
- Decreased iron absorption
- Decreased calcium absorption leading to hip fractures in elderly
- Clostridium difficile infection risk > 6 months
- inappropriate ADH secretion
hepatotoxicity medication
- flucloxacillin
- methotrexate
- PTU
- Statin
- Paracetamol
- Phenytoin
neurotoxic medication
- Cefepime (elderly)
Tetracycline side effects
- Severe photosensitivity.
– Discolorations of the skin.
– Pneumonitis.
– Serum sickness.
– Autoimmune hepatitis
NOTE: contraindicated in children < 8 years due to dental staining
Causes of pinpoint pupils
1- Structural pons disease.
2- Opiates such as heroin and morphine
3- Barbiturates.
4- Organophosphates.
5- Clonidine.
6-Pilocarpine eye drops-para-sympathomimetic alkaloid
Glyceryl trinitrate failing to provide adequate symptom relief
- Reduced drug potency
- Tolerance
CCB drug interaction
combined with NSAIDs increases the risk iof bradycardia
ACEi side effects
angioedema
ACEi contraindications
Absolute:
- History of angioedema regard less of cause
- (even if not due to ACE inhibitor)
- Pregnancy (due to harm to fetus)
- Bilateral renal artery stenosis
- Previous allergic reaction to ACE inhibitors
Relative
- Aortic stenosis
- Hypertrophic cardiomyopathy
ACEi renal injury
Decreasing renal efferent vasoconstriction
- Found in bilateral RAS
- combined with NSAIDs increase the risk of prerenal failure
Aromatase inhibitors side effects
- osteoporosis
- cardiac issues
Aromatase inhibitors indications
Block oestrogen synthesis
- used for breast and ovarian cancer
Acetazolamide indications
– Acute angle-closure glaucoma
– Treatment of altitude sickness.
– Prevention of altitude sickness.
– Idiopathic intracranial hypertension
Cardiac arrest due to hypokalaemia
- 5mmol Potassium chloride
Exenatide mechanism of action
- increases insulin secretion in response to eating meals
- Higher insulin to lover blood sugar rise from food
- slows down gastric emptying
- suppresses glucagon
Bupivacaine
- more potent and longer duration of action than lignocaine
- also more cardiotoxic than lignocaine
- side effects and toxicity are additive of the two local anaesthetics
- in addition with epinephrine prolongs duration of action + decreases local bleeding
Tirofiban contraindications
glycoprotein IIb/IIIa inhibitor
-History of intracranial neoplasm
-Acute pericarditis
– History of vasculitis
– Aortic dissection
HRT side effects
1-Increased risk of acute coronary syndromes.
2-Stroke.
3-Pulmonary embolism.
4-Deep venous thrombosis.
5-Reduced cognitive functions
thiazolidinedione contraindications
- Any degree of cardiac failure (absolute)
- History of cardiac failure
- -Ischemic heart disease (especially those on nitrates)
- -Liver dysfunction (relative contraindication)
azathioprine for RA testing
Thiopurine methyltransferase (TPMT) enzyme activity (most important)
- can result in severe
immunosuppression
Chest X-ray,
FBC
CRP
ESR
hepatitis B & C
renal and liver function tests
Drugs that can cause hypokalaemia and metabolic acidosis
Acetazolamide
Thiazide with loop diuretics
Thiazide side effects
1-Hyponatraemia.
2-Hypokalaemia.
3-Hyperuricaemia.
4-Orthostatic hypotension.
5-Hypomagnesaemia.
6-Hyperglycaemia.
7-Hypercalcaemia.
8-Dyslipidaemia-increase in cholesterol, LDL and triglyceride concentration and reduce HDL.
9-Orthostatic hypotension and dizziness.
Drugs that can cause hyperkalemia and metabolic acidosis
Amiloride
Statin
HMG-CoA reductase inhibitor metabolised by CYP3A4
statin + macrolide antibiotics
macrolide antibiotics inhibits the CYP3A4-mediated metabolism of statin, leading to its increased serum concentrations and toxic effects
- result in rhabdomyolysis and myopathy
digoxin + macrolide antibiotics
enhance the oral bioavailability of
digoxin leading to increased serum digoxin concentrations and possible digoxin toxicity
digoxin + spironolactone
digoxin toxicity by hyperkalaemia
1-Prolongation of half-life of digoxin
2-Dehydration can cause renal failure and decrease renal clearance of digoxin.
3-Hyperkalemia can be a presentation of severe digoxin toxicity due to potassium sparing effect of spironolactone
digoxin toxicity
Nausea + vomiting (initial)
digoxin toxicity management
- serum concentration should be measured at 6 hours from last dose
- then every 2 to 4 hours until
the concentration has decreased to normal range.
aminoglycoside antibiotics contraindications
Ototoxic
- Concomitant use with furosemide
- chronic kidney disease
- Concomitant use of streptomycin
- myasthenia gravis
sulfasalazine contraindications
skin rash
- hepatitis
- pancreatitis
- pneumonitis
-agranulocytosis
- thrombocytopenia
- aplastic anaemia
sulfasalazine side effects
- nausea,
- headache
- fever
- rash
- oligospermia and infertility (reversible with drug
discontinuation)
Empagliflozin
sodium glucose co-transporter 2 (SGLT2) inhibitors
- reduce cardiovascular mortality 35%
- glycosuria results in improved diabetes control
SGLT2 side effects
– Weight loss.
– Aggravation of the level of dehydration due to fluid losses from the kidney.
– Increased risk of urinary tract infections.
Absolute contraindications to epidural anaesthesia
-Patient refusal
-Full anticoagulation
-Infection at the injection site
-Septicaemia
-Hypovolaemia
-Allergy to local anaesthetic
Relative contraindications include:
-Partial anticoagulation
-Pre-existing neurological deficit
-Back pain
Glucocorticoids in increased bones loss
direct suppressive effect on osteoblastic activity
- increases bone resorption and reduces bone formation
acetylcholinesterase inhibitors (AChEIs) contraindications
-Gastrointestinal or ureteric obstruction.
-Active peptic ulcer.
-Heart block.
-Bradyarrhythmias (including sick sinus syndrome).
-COPD
-Parkinson’s disease
flushing + erythema + pruritus more predominant in the upper boys, face and neck
Red Man Syndrome
- Idiosyncratic drug reaction
Red Man Syndrome management
mild/moderate reactions: lower infusion rate of vancomycin + antihistamine
Aspirin indications
1- Coronary angioplasty
2- Coronary artery bypass graft
3- Peripheral arterial disease and coronary artery disease
4- Peripheral arterial grafting
5- Suspected or evolving myocardial infarction
6- Stable and unstable angina
7- Atrial fibrillation
Apixaban dose reduction indication
reduced to 2.5mg twice daily
– Age more than 80 years.
– Weight below 60 Kg.
– Chronic renal failure with a serum creatinine of higher than 133 µmol/L
Apixaban contraindication
creatinine clearance is below 25ml/min
Apixaban surgery indication
Non-valvular AF
- Elective hip or knee surgery
Most common side effect of CCB
peripheral oedema
- headache 2nd most common
CC + SSRI
hypotension and compensatory tachycardia
- SSRls inhibit hepatic metabolism of CCBs leading to increased plasma levels of nifedipine
Chemotherapeutic + RA
Macroscopic haematuria
- give Mesna
Doxorubicin primary toxicity
Dilated cardiomyopathy
Niacin inhibitor
- azathioprine
- 5-flurouracil
- 6-mercaptopurine
- phenobarbitone
Niacin analogue
Isoniazid
