In a patient with toxin-induced bradycardia and hypotension, here is a quick differential to help identify the responsible substance:
Less commonly seen causes include: magnesium, propafenone, and plant toxins (aconitine, andromedotoxin, veratrine).
In the state of Maryland, the most common venomous snake is the copperhead. Though not as dangerous as the rattlesnake, it can still cause loss of function of limb and mortality in the pediatric patient.
Treatment has involved the use of CroFab (Protherics, Atlanta). This ovine derived monovalent immunoglobolin is actually made against the following snakes:
Though efficacy has been shown with these snakes, we are hoping for cross-reactivity when we treat copperheads. There are case series and case reports (1) that have shown anectdotal improvement. We are still awaiting a real randomized controlled trial - may never happen.
Physostigmine has been used extensively in the fields of anesthesiology and emergency medicine. The only use of physostigmine with sound scientific support is for the management of patients with an anticholinergic syndrome, particularly those without cardiovascular compromise who have an agitated delirium. In this population, physostigmine has an excellent risk-to-benefit profile.
There are a several classes of medications that can kill a toddler with a single dose. Toddlers are particularly susceptible due to their low weights and propensity to place everything in their mouths.
1. Calcium channel blockers
2. Camphor-containing rubs
3. Opioids/opiates
4. Oil of wintergreen/ aspirin
5. Cyclic antidepressants
6. Topical blood pressure patches (clonidine)
7. Eye drops and nasal sprays (oxymetazoline)
8. Sulfonylureas
9. Antimalarial drugs (cloroquine)
Scombroid is caused by ingestion of preformed histamine on skin of fish.
We are all familiar with the classic ECG abnormalities caused by the sodium channel blocking properties of tricyclic antidepressants (QRS interval widening, R wave in aVR, S wave in I and aVL, and rightward deviation in terminal 40 msec of QRS). Here are some other medications that also block cardiac sodium channels in a similar manner:
It is likely that you will be asked questions about the huge recall by McNeil..
It stems from complaints received of black particles found in the pediatric liquid formulation, which are manufactured at one facility in Fort Washington, PA. The FDA inspected the plant and found inadequate quality standard testing and facilities. Either there were potential bacteria in one of the raw products (which did not make it to the final product), or the final concentrations were stronger than specified.
McNeil recalled forty-three formulations of pediatric liquid tylenol, zyrtec, motrin and benadryl. Generic versions are unaffected.
Complete recall information:
www.mcneilproductrecall.com
For more information and links:
http://www.fda.gov/Safety/
Here are is a list of common drugs that will cause thrombocytopenia as a result of antiplatelet antibodies (its not just heparin!). This list is not complete but are common ones that you will see in the ED, coming from USH or on the floors/units during residency:
Abciximab, Acetaminophen, amiodarone, amphotericin B, ASA
Carbamazepine, cimetidine
Digoxin
Methyldopa
Quinidine, Quinine
Rifampin
Trimethoprin-sulfamethoxazole
Vancomycin
Several drugs and compounds may be radiopaque on an abdominal radiograph. This may be helpful in an overdose to determine ingestion or amount ingested. Attached is a pic a patient that ingested potassium sustained release tables.
The mneumonic CHIPES will help you remember which are:
C - Calcium Carbonate, chloral hydrate
H - Heavy metal - like Mercury, lead
I - Iron and Iodine
P - Phenothiazines (compound that has S(C6H4)2NH in it), drugs that include: antipsychotics like chlorpromazine (thorazine) and antiemetics like prochlorperazine (compazine)
E - Enteric coated pills
S - Solvents [halogenated ones like chloroform] and Sustained Release preparations [Lithobid and K-Dur]
Many drugs/toxins cause nystagmus, particularly in overdose. Vertical, horizontal, or rotary nystagmus may be noted.
The most common drug/toxin overdoses that cause nystagmus are the following:
When you draw a urine toxicology screen it can mislead more often than help you. Here is a quick list of the test followed by some medications that cause false positives - when in doubt, call your lab to find out specifics since results will vary lab to lab:
TCA - diphenhydramine, carbamazepine, cyclobenzaprine (side note: TCA screen should never be used to determine TCA toxicity, your ECG and physical exam should be enough to determine if the patient is toxic from TCA
Cocaine - the most accurate test on the screen, positive for up to 5 days
PCP - dextromethorphan and ketamine can turn it positive
Amphetamines - pseudoephedrine, ephedrine, phenylephrine and many other OTC cough decongestants can as well, the worst screening test with the largest number of false positives
According to the Food Allergy and Anaphylaxis Network, the eight most common food allergies, which account for 90% of the food allergies in the U.S., are: dairy, soy, wheat, shellfish, fish, peanut, tree nut, and egg.
Several medications are formulated with these ingredients and should be avoided in patients with reported allergies.
| Cutting Edge | Old School |
| Gastric Lavage | |
| Hyperinsulinemia and Euglycemia | Supportive care, glucagon for beta blocker overdoses |
| Intralipid administration | Supportive care for anesthetic overdoses, TCAs, and other lipid soluble agents |
| Low dose or NO narcan | High dose narcan for opoid overdoses |
| Checking salicylates and tylenol levels for overdose | Tox screens for everyone |
When a child is reported to be exposed to a rat poison it is commonly a long acting coumarin like brodifacoum. The rat usually eats the poison then during its traumatic little life will cause its own death by jumping and squeezing through a crack. When a human is exposed, this is the typical sequence of events:
Treatment is the same as for coumadin, vitamin K. However, do not start empirically since the patient will be committed to high doses of vitamin K for several months. Let the patient prove they have been poisoned which means they will require recheck of their INR 2-3 days later though they can be sent home with specific warning signs of anticoagulation.
With all of the post-transplant patients we see in the ED, a refresher on the toxicities associated with the most common immunosuppressant medications is warranted.
Cyclosporine (Sandimmune® and Neoral®/Gengraf®) and tacrolimus (Prograf®) are both calcineurin inhibitors that inhibit activation and proliferation of T-lymphocytes and IL-2.
- Major concerns: Nephrotoxicity, drug interactions (CYP3A4)
- Adverse Effects:
o Electrolyte abnormalities: K+, ¯Mg+, glucose
o CNS: HA, tremor (statistically higher with tacrolimus)
o CV: HTN, lipids (increased with cyclosporine)
o End organ: hepatotoxicity, nephrotoxicity
o Cosmetic (cyclosporine specific): hirsutism, gingival hyperplasia, acne
Sirolimus/Rapamycin (Rapamune®) is an M-tor inhibitor that inhibits T-lymphocyte activation and proliferation.
- Major concerns: Drug interactions (CYP3A4)
- Adverse Effects:
o Delayed wound healing
o Leucopenia, thrombocytopenia
o Hypercholesterolemia
CARBAPENENEMS
TIGECYCLINE
AMIKACIN
COLISTIN
Radiocontrast Induced Nephropathy (RCIN)
Quinolone Induced Deliurim
Just to give you another reason NOT to give a quinolone - aside from the C. diff. This adverse effect occurs with quinolones unlike many other antibiotics. It can prolong hospital stay, cause falls and further medical work ups. Some risk factors are: