There are only a few toxins that directly cause acidosis:

• alcohol
• methanol
• paraldehyde
• isoniazid (lactic acid)
• ethylene glycol
• salicylates
• glyphosate

However

• renal failure (GFR < 10% of normal)
• lactic acidosis

may occur secondary to tissue hypoxia, shock or seizures from poisoning with many toxins including:

• Sympathomimetic drugs
• Carbon monoxide
• Tricyclic antidepressants
• Cellular poisons (e.g. colchicine, iron)

Drug toxicity worsened by acidosis:

• Tricyclic antidepressants
• Antiarrhythmic drugs
• Quinidine

Features that help to differentiate between these drugs are:

• LEVEL OF CONSCIOUSNESS
• HYPERREFLEXIA
• HEART RATE
• ECG CHANGES
• ELECTROLYTES/BLOOD GLUCOSE
• OSMOLAL GAP
• BLOOD CONCENTRATIONS