Pharmacology & Toxicology Flashcards
Causes of Hyperpyrexia (7)
- Salicylates *
- Ecstasy *
- Cocaine *
- Neuroleptic malignant syndrome
- Serotonin syndrome
- Thyroid storm
- Co poisoning *
3 Drugs casuse sensorineural deafness
- Lasix iv ( oral unlikely)
- Vancomycin iv
- Erythromycin iv
6 Drug induced impaired glucose tolerance
- Nicotinic acid ( Vit B3)
- Atypical antipsychotics ( olanzapine )
- Tacrolimus & cyclosporine
- Steroids
- Interferon alpha
- Thiazides & lasix
*NAT SIT
4 Drug causes of urticaria
- NSAIDS
- Opiates
- Penicillins
- ASA
- NOPA
7 Drugs causing photosensitivity
- NSAIDS
- ACEi/ ARBs
- Sulfphonylureas
- Thiazides
- Amiodarone
- Psoralens
- Tetracycline, sulphonamide, cipro
- NAS TAPT
3 Drug causes of gingival hyperplasia
- Cyclosporine
- Phenytoin
- CCB ( especially Nifedipine)
*CPC
5 Drug causing lung fibrosis
- Amiodarone
- Methotrexate & sulfasalazine
- Bleomycin & busulphan
- Nitrofurantoin
- Bromocriptine , cabergoline, pergolide
5 Drug induced urinary retention
- Disopyramide
- Opioids
- Tricyclic antidepressants
- Anticholinergics ( antipsychotics & antihistamine)
- NSAIDS
- DO TAN
Drug induced pancytopenia
- Cytotoxics
- Antibiotics: trimethoprim, chloramphenicol
- Anti-rheumatic: Gold , penicillamine
- Carbimazole
- Phenytoin, carbamazepine
- Sulphonylureas
Drug causes of agranulocytosis
- Antithyroid drugs - carbimazole, propylthiouracil
2.Antipsychotics - atypical antipsychotics (CLOZAPINE)
3.Antiepileptics - carbamazepine
4.Antibiotics - penicillin, chloramphenicol, co-trimoxazole
5.Antidepressant - mirtazapine
6.Cytotoxic drugs - methotrexat
1 Drugs causing Cataracts
steroids
2 Drugs causing Corneal opacities
amiodarone
indomethacin
3 Drugs causing Optic neuritis
amiodarone
ethambutol
metronidazole
Drugs causing Retinopathy
chloroquine, quinine
Drugs causing blue discolouration and non-arteritic anterior ischaemic neuropathy
Sildenafil
Alcohol drinking management
Ora thiamine
Benzodiazepines for acute withdrawal
Disulfram
Acamprosate
Stages of Ethylene toxicity
Stage 1: symptoms similar to alcohol intoxication: confusion, dizziness, dysarthria
Stage 2: metabolic acidosis, high Anion Gap & high osmolar gap, tachycardia, HTN
Stage 3: AKI
Treatment of ethylene toxicity
- fomepizole is preferred to ethanol
- hemodialysis
Treatment of Methanol poisoning
- fomepizole
- hemodialysis
- cofactor therapy with folinic acid to reduce ophthalmological complications
Ecstasy poisoning features
CNS: agitation, confusion , ataxia
CVS: tachycardia and HTN
Fever
Hypo Na
Rhabdomyolsis
Ecstasy poisoning management
- supportive
- dantrolene maybe used for fever if other simple measures fail
Carboxyhemoglobin level in non smoker
< 3 %
Carboxyhemoglobin level in smoker
< 10 %
Carboxyhemoglobin level in symptomatic
10-30 %
Carboxyhemoglobin level in severe toxicity
> 30 %
in Carbon monoxide poisoning , ECG is useful to look for …..
Cardiac ischemia
Treatment of CO poisoning
- 100 % high flow O2 via Non rebreather mask
- Minimum 6 hrs
- Target SPo2 100 %
5 Indication of hyperbaric oxygen in CO poisoning
- Level > 25 %
- Pregnancy
- Neurological signs
- Myocardial ischemia
- Arrhythmia
5 Features of Mercury poisoning
- Visual field defects
- Hearing loss
- Irritability
- Paraesthesia
- RTA
2 Risk factors of Paracetamol overdose
- Malnourished patients ( e.g anorexia nervosa) or patients who have not eaten for a few days
- Hepatotoxic Drugs ( rifampicin, phenytoin, carbamazepine, chronic alcohol excess
** acute alcohol intake is not risk factor
** maybe protective
Acetyl cysteine is used in ttt of paracetamol overdose as it’s …….
It’s a precursor of glutathione and hence can increase hepatic glutathione production
Side effect of acetylcysteine ?
And how to treat?
Anaphylactoid reaction
- stop iv acetyl cysteine then restarting at slower rate
Criteria for liver transplant in paracetamol liver failure
- PH < 7.3 , 24 hrs after ingestion
Or
- PT > 100 sec & creat > 300 & encephalopathy grade III or IV
Paracetamol overdose occurs when glutathione stores run out leading to ….
Increase NAPQI ( N acetyl p benzoquinone imine)
Fomepizole is an inhibitor of ….
Alcohol dehydrogenase
Confusion and pink mucosae
CO poisoning
Features of organophosphate poisoning
Salivation
Lacrimation
Urination
Defecation
Hypotension
Bradycardia
Small pupils
Muscle fasciculation
Drugs that can be cleared with hemodialysis
BLAST
- Barbiturates
- Lithium
- Alcohol ( methanol & ethylene glycol)
- Salicylate
- Theophylline ( charcoal hemoperfusion is preferred)
Drugs that can ( not ) be cleared with hemodialysis
- Tricyclics & benzodiazepines
- BB & digoxin
- Dextropropoxyphene
BB overdose features & treatment
Hypotension
Bradycardia
HF
Syncope
Ttt:
If bradycardia»_space; >atropine
In resistant cases»_space;> glucagon
Treatment of organophosphate poisoning
- Atropine
- pralidoxime
Salicylate overdose features
- Mixed respiratory alkalosis and metabolic acidosis
- Hyperventilation
- Seizures and coma
- Sweating and fever
- Hyperglycemia and hypoglycemia
- Tinnitus and lethargy
Salicylate overdose treatment
- ABC
- Charcoal
- Urinary alkalinization with iv NaHco3
- Hemodialysis
6 Indications for hemodialysis in Salicylate overdose
- Serum concentration > 700 mg/l
- Persistent metabolic acidosis
- AKI
- Pulmonary edema
- Seizures
- Coma
Cyanide poisoning features
Classical features: Brick red skin & Smell of bitter almonds
Acute : hypoxia , hypotension, headache, confusion
Chronic: ataxia, peripheral neuropathy, dermatitis
Cyanide poisoning management
- 100 % O2
- Iv hydroxocobalamin
- combination of amyl nitrite , Na nitrite and Na thiosulfate
Botulinum toxin indications
- Achalasia
- Severe hyperhidrosis of the axillae
- Hemifacial spasm
- Blepharospasm
- Spasmodic torticollis
- Focal spasticity in cerebral palsy, hand& wrist disability associated with stroke
When should measure digoxin level If suspected digoxin toxicity
Within 8 -12 hrs of the last dose
Features of digoxin toxicity
Lethargy, confusion
Nausea and vomiting and anorexia
AV block , bradycardia
Gynecomastia
Precipitating factors for digoxin toxicity
- Hypo K , Hypo Mg , Hypoalbuminaemia
- hypothermia, hypothyroidism
- hyper Ca , Hyper Na
- renal failure, acidosis
- myocardial ischemia
- old age
- drugs
Precipitating factors for digoxin toxicity
( drugs )
- amiodarone, Verapamil, diltilazem
- quinidine
- ciclosporin , spironolactone
- drugs can cause Hypo K: thiazides, loop diuretics
Management of digoxin toxicity
- Digibind
- Correct arrhythmias
- Monitor potassium
Treatment of lead toxicity
Dimercaprol , Ca edetate
Treatment of benzodiazepines overdose
- Supportive care
- Flumazenil ( can cause seizure) only with severe or iatrogenic overdose
Lithium toxicity occurs when the concentration level
> 1.5 mmol/L
Lithium toxicity maybe precipitated by
Dehydration
Renal failure
Drugs: thiazides, ACEi/ARBs , NSAIDS, Flagyl
Features of lithium toxicity
- Coarse tremor ( fine tremor in therapeutic level )
- Hyperreflexia
- Confusion , seizure , coma
- Polyuria
Cocaine mechanism of action
Cocaine block the uptake of dopamine, noradrenaline and serotonin
Treatment of cocaine toxicity
- benzodiazepines first line
- chest pain: benzodiazepines + glyceryl trinitrate, if MI»_space; PCI
- HTN : benzodiazepines + Na nitroprusside
- BB in cocaine induced cardiovascular problems
Early features of tricyclic overdose
- Dry mouth
- dilated pupils , blurred vision
- agitation
- sinus tachycardia
4 features of severe poisoning in
tricyclic overdose
- seizures,
- coma
- metabolic acidosis
- arrhythmias
ECG changes in tricyclic overdose
- sinus tachycardia
- widening of QRS
- Prolongation of QT interval
In tricyclic overdose , Widening of QRS
- > 100 associated with …….
- > 160 associated with ……
I. Seizures
- VT
Treatment of tricyclic overdose
- IV bicarbonate
- first-line therapy for hypotension or arrhythmias
- indications include widening of the QRS interval >100 msec or a ventricular arrhythmia
- other drugs for arrhythmias
CCB side effects
- Headache
- Flushing
- Ankle oedema - Verapamil also commonly causes constipation
BB side effects
- Bronchospasm (especially in asthmatics)
- Fatigue
- Cold peripheries
- Sleep disturbances
Nítrates side effects
- Headache
- Postural hypotension
- Tachycardia
Nicorandil side effects
- Headache
- Flushing
- Anal ulceration
Drug causing yellow green tinge in vision
Digoxin
Classical hallmark of Quinine toxicity
(cinchonism)
- Tinnitus, visual blurring
- dry skin
- arrhythmias
- pulmonary edema
- abdominal pain
- hypoglycemia
Arrhythmias in Quinine toxicity due to…
Blockade of Na & K channels prolonging QRS & QT interval and these generate into ventricular tachyarrythmias or fibrillation causing death.
Hypoglycemia in Quinine toxicity due to
Quinine stimulates pancreatic insulin secretion
Quinine toxicity vs Aspirin poisoning
Difficult to distinguish so measure salicylate levels is important
- tinnitus & deafness & visual defects are transient with Aspirin
But permanent with quinine
Management of Quinine toxicity
- supportive with fluids , Inotropes
- bicarbonate as needed
- positive pressure ventilation for pulmonary edema
Iron tables overdose features
- Hypotension
- Abdominal pain
- Coffee ground vomiting & black stool
- metabolic alkalosis 2ry to vomiting
- iron table radio-plaque in X-ray or CT
Treatment of Iron tables overdose
- Gastric lavage with desferrioxamine into stomach to reduce further iron absorption
- iv desferrioxamine at rate 15 mg/kg/hr is an initial ttt of choice and it’s important to start with it as soon as possible
- hemodialysis
- plasma exchange
Ethambutol inhibits
the enzyme arabinosyl transferase which polymerizes arabinose into arabinan