What medications (OTC and prescription ) and/or household products can cause severe toxicity in small doses in younger children? What are their manifestations?
TCAs: Cardiac sodium channel blocking effects leading to widening of QRS interval on EKG, ventricular arrhythmias, hypotension, CNS depression, seizures, and ANTICHOLINERGIC toxicity.
Calcium channel antagonists: Hypotension, bradycardia. Symptoms should be seen within 3 hours with regular preparations, but may not be seen for up to 14 hours in sustained-release preparations.
Beta blockers: The hypotension and bradycardia (while potentially dangerous) are generally well tolerated by children; however, hypoglycemica (leading to seizures and coma) is a huge consideration. Lipophilic beta blockers (e.g., propranolol) possess TCA-like sodium channel blocking activity.
Flecanide (Class 1C anti-arrhythmic used to treat supraventricular and ventricular arrhythmias): Blocks Na chnnels, leading to: nausea, vomiting, hypotension, bradycardia, AV block, and/or tachyarrhythmias. It has a case fatality of approximately 22%.
Clonidine: Can cause toxicity rapidly and is especially dangerous in the patch form (up to 7.5 mg of clonidine). The classic triad is: skin pallor, miosis, and bradycardia. Children typically present with altered mental status and should be watched for 4-6 hours (24 if patch is involved).
Oral hypoglycemics (generally sulphonylureas): Absorbed rapidly from GI tract. Blood glucose should be monitored for at least 8 hours (normal preparations) or 24 hours (extended release preparations).
Antimalarials: Chloroquine is prescribed for treatment of malaria and rheumatoid disease (including SLE). Hypotension and myocardial depression can lead to potentially fatal cardiogenic shock and/or ventricular arrhythmias. Neuro signs include: seizure, AMS, coma, myopathy, neuropathy, and hypokalemia. Ocular and ototoxicity are common in quinine ingestion.
Alcohols: Ethanol (hypoglycemia and CNS depression), ethylene glycol and methanol (metabolic acidosis with anion gap indicates poisoning), and isopropanol (rubbing alcohol) and acetone (CNS depression—ataxia, confusion, stupor; and GI effects, including: nausea/vomiting and abdominal pain).
Cleaning products: Soaps (pH <3 or >13 are toxic: lavatory/drain/oven cleaners). Children must be observed if: they are drooling or refuse to swallow OR are complaining of pain of the mouth or chest.
Camphor: Common ingredient in OTC topical liniments (VapoRub and Tiger Balm) and in insecticides. Seizures are most common manifestation (usually occur within 90 minutes of ingestion).
Methyl salicylates: Very concentrated in oil of wintergreen. Causes direct stimulation of medulla, leading to: nausea/vomiting, tinnitus, deafness, hyperventilation, respiratory alkalosis, hypoglycemia, hypokalemia, fever and sweating. Later effects include: seizures, AMS, coma, cerebral/pulmonary edema, RDS, and renal failure.