Capsule cases Flashcards
How to deal with suspected poisoning / overdose ?
Assess :
- Level of consciousness - Glasgow
coma scale
- Breathing - respiratory rate , pulse
oximetry if possible.
- circulation - BP , pulse , temperature
- examination
- Taking history
The history should include:
0 Why was the substance taken?
0 What substance(s) were taken?
0 When was it taken? - exact time of ingestion - especially important for paracetamol poisoning.
0 Who was involved - Age , sex , past medical history etc.
Arrange emergency transfer to hospital following the immediate assessment of the person if:
- The person is unconscious or has a reduced level of consciousness.
- reduced respiratory rate or oxygen saturation is reduced. - hypotension. - tachycardia or bradycardia or a irregular pulse. - hypothermic or hyperthermic - having seizure If there are any other concerning clinical features
Assess - in the case of self harm a mental state of patient.
Consquences /(signs / symptoms of Paractamol poisoning ?
- NOTE - PARACETONOL OVERDOSE - MOST COMMON CAUSE OF ACUTE LIVER INJURY
COMMON
- Nausea and Vomiting (only early signs - settle with 24hrs)
UNCOMMON
- Right subcostal pain - development (suggest Hepatic necrosis) -
Hepatic necrosis can lead to : - encephalopathy -effects the function/ structure of brain) )
(occcurs because liver dysfunction impairs its function to remove toxins so these build up in blood and eventually travel to the brain.) - Hypoglycaemia
- haemorrhage
- cerebral oedema
OTHERS - Jaundice
- asterixis
(signs of acute liver injury)
*if have loin pain or proteinuria at least 24 hrs after para ingestion or serum creatinine > 300 mircomoles / L - sign of acute kidney injury
( if presenting 24 hrs after para ingestion - suspect kidney failure)
- People may also present with coma or a reduced level of consciousness if they have taken paracetamol with a drug that reduces the level of consciousness, e.g. opioids (for example a combined paracetamol/opioid preparation) or alcohol.
- Toxic doses of paracetamol may cause severe hepatocellular necrosis and, much less frequently, renal tubular necrosis. Liver damage is maximal 3–4 days after paracetamol overdose and may lead to hepatic failure, encephalopathy, coma, and death.
RISK FACTORS
- History of self harm
- history of repeated / frequent use of medications for pain relief.
- Glutathione deficiency ( glutathione aids in detoxification of products of paracetamol, when this happens the toxic products bind to hepatic tissue and cells & cause damage ) - seen in pl with malnourishment.
- drugs that induce liver enzymes (Cytochrome p450 inducers e.g. arbamazepine, phenobarbital, phenytoin, primidone, rifampicin, rifabutin, efavirenz, nevirapine, and St John’s wort.)
What patients should be urgently referred in the case of posioning?
- All children and young people who have deliberately self-poisoned.
- Adults who have deliberately self-poisoned.
- People who are symptomatic.
- People who have taken poisons with a delayed action. These include aspirin, iron, paracetamol, tricyclic antidepressants, co-phenotrope and all modified-release preparations.
- Where the type of poison is unknown.
Treatment of paracetamol poisoning ?
IV - Acetylcysteine / N- Acetylcysteine - IV INFUSION!!!!!!
(can be given oral if IV not possible - unlicensed ) - 3 IV infusion over 21 hours.
0 Prevents or reduces the severity of liver damage if given within 24 hours (possibly beyond) of ingesting paracetamol.
0 Most effective if given within 8 hours of paracetamol ingestion, after which effectiveness declines.
Methionine is an alternative agent given orally - treats acetaminophen (american name )/paracetamol poisoning
- LOOK AT FOLLOWING - THIS IS THE ONE YOU SHOULD MEMORISE
ACUTE SINGLE OVERDOSE
Supportive care + (consider activated charcoal ) + ( consider acetylysteine )
Consider activated charcoal if within 1 hour of ingesting more than 150mg/kg of paracetamol.
- be careful of activated charcoal - in those with reduced GI molitilty (risk of small bowel obstruction) & comatose or drowsy (risk of aspiration)
Consider acetylsteine - if ingested more than 150 mg.kg taken within one hour (or acute overdose) & there will be a delay of more than 8 hours in getting serum paracetamol conc. ———————————————————————————-> if ingested less than 150mg/kg - wait for blood results before starting acetylcysteine - if one or above treatment threshold give acetylcysteine. ( treatment line will be down my nonogram (graph)
- Can consider anti -emetic (ondasetron) - vomiting common for acetylcysteine - vomiting does not effect efficacy of treatment
STAGGERED OVERDOSE
Supportive treatment +
GIVE ACETYLCYSTEINE IMMEADIETELY irrespective of serum para concentration
( why ? - staggered overdoses are high risk & associated with reduced survival - bcc more likely to have risk factors older , more likely to abuse alcohol etc. )
Consider anti-emetic
THERAPEUTIC EXCESS
1ST LINE
Supportive treatment
PLUS ACETYLCYSTEINE if therapeutic excess + any one of these :
- Serum para conc >/= 10mg/L
- ALT is above upper level
- INR > 1.3
Consider anti - emetic
- note acetylcysteine indusion - should only be given closely mointored area - monitor for reactions : nausea , vomiting , flushing , urticarial rash , angioedema , tachycardia & bronchospasm - COMMON SIGNS ,
Overall treatment of poisoning / overdose ?
Activated Charcoal - Give by mouth - mixed with liquid .
* increases elimination of drug , passes through the GI tract faster - less absorbed into body.
0 Effective with 2 hours of ingestion.
If vomiting occurs - give anti -emetic (vomiting can reduce Charcoal efficacy )
Charcoal, activated should not be used for poisoning :
- petroleum distillates,
- corrosive substances,
- alcohols,
- malathion,
- cyanides
- metal salts including iron and lithium salts.
Side effects -of Acetylcysteine ?
Rash - most common - continue treatment.
What is aspirin ? - what is it derived from .
Consequences of Salicylate poisoning ?
Salicylates - derivatives of salicylic acid.
Aspirin is a salicylate . (acetylsalicylic acid)
- Hyperventilation,
- tinnitus, (ringing in the ears)
- deafness,
- vasodilatation,
- sweating.
- Coma if very severe poisoning.(uncommon)
Patients present with respiratory acidosis followed by metabolic acidosis.
*hyperglycaemia - recognised complication of this overdose.
Treatment of Aspirin poisoning ?
Haemodialysis -
severe salicylate poisoning
considered :
- when plasma-salicylate concentration exceeds 700 mg/litre (5.1 mmol/litre)
- in the presence of severe metabolic acidosis.
- Activated charcoal can be given within 1 hour of ingesting more than 125mg / kg of aspiring.
0 Alkalisation of urine - IV Sodium bicarbonate - (increase PH of urine ) - increases elimination of salicylates.
- Plasma-potassium concentration should be corrected before giving sodium bicarbonate as hypokalaemia may complicate alkalinisation of the urine.
Precise treatment of paracetamol poisoning for single acute Overdose ?
0 -8 Hrs
Consider activated charcoal if
presentation within 1 hour from
ingestion.
Take bloods 4 hours after
ingestion and await plasma
paracetamol levels.
Treat if above, on, or slightly
below the appropriate treatment
line
8- 24 Take bloods If >150 mg/kg give acetylcysteine immediately. If < 150 mg/kg, wait for blood results before considering treatment.
>24 Take bloods If patient is jaundiced or has hepatic tenderness treat with acetylcysteine. Otherwise wait for blood results before commencing treatment. Treat if: Paracetamol detected. INR >1.3 ALT > X2 times the upper limit of normal.
What groups should be treated for a paracetamol poisoning at lower levels ?
- Alcoholics
- HIV positive
- Malnourished
- Epileptics
- Cirrhotic
Those with pre-existing liver disease or on enzyme-inducing drugs e.g. phenytoin, carbamezopine for epilepsy need treatment at lower paracetamol levels.
What is Methotreaxte and Sulfaslazine ?
Immunosuppressant - treat inflammatory conditions
Rheumatoid arthritis - 7.5mg
- Psoriasis - include - psoriasis arthritis.
also sarcoidosis
- taken once a week
- folic acid can be given in conjunction . Take day after methotrexate. (Methotrexate can decrease levels of vitamin e.g. folate) - METHOTREXATE - FOLIC ACID ANTAGONIST.)
- methotrexate - cytotoxic agent (kills cancer cells and can damage normal tissue)
Sulfasalazine - Anti -inflammatory drug
Treat :
Rheumatoid A
Ulcerative colitis
Crohns disease.
What is Methotreaxte and Sulfaslazine ?
Immunosuppressant - treat inflammatory conditions
Rheumatoid arthritis - 7.5mg
- Psoriasis - include - psoriasis arthritis.
also sarcoidosis
- taken once a week
- folic acid can be given in conjunction . Take day after methotrexate (\BCC THE 2 DRUGS HAVE OPPOSING EFFECTS). (Methotrexate can decrease levels of vitamin e.g. folate) - METHOTREXATE - FOLIC ACID ANTAGONIST.)
Multi- Vitamin supplements should be avoided as have Folic acid and could interfere with action of methotrexate.
- methotrexate - cytotoxic agent (kills cancer cells and can damage normal tissue)
Sulfasalazine - Anti -inflammatory drug -orange / yellow colour ( can cause orange ting to urine)
Treat :
Rheumatoid A
Ulcerative colitis
Crohns disease.
What needs to be monitored with methotrexate therapy ?
Chest X ray recommended before starting therapy. ( mostly with rheumatoid athritis)
Increased concentrations can be toxic can cause:
- liver damage - if substantial hepatic functions abnormalities - treatment suspended for minimum 2 weeks. Substance toxic to the liver should also be avoided e.g. alcohol. if abnormalities back to normal therapy can continue.
- Kidney damage
- Suppression of cell production from bone marrow.
- profound drop in WBC or platelet count - stop treatment. )
Methotrexate and NSAIDS ?
Use of them together is safe providing monitoring of methotrexate levels is done.
Risk of methotrexate toxicity in High dose patients -
( * inhibit the synthesis of prostaglandins resulting in a fall in renal perfusion, which could lead to a rise in serum methotrexate levels accompanied by increased toxicity. )
NSAIDS
0 Ibuprofen
0 Dicofenac
0 Aspirin
0 Naproxen
Trimethoprim , methotrexate ?
DON’T USE TOGETHER.
Trimethoprim - folate anatgonist and so is Methotrexate
Also impairs bone production , trimethoprim makes it worse. ( myelosuppression)
Both increase risk of nephrotoxicity.
- reported to cause acute megaloblastic pancytopenia in rare instances.
