Poisoning by histamine H2-receptor blockers, acc, init

This code signifies an accidental overdose or adverse reaction to a histamine H2-receptor blocker, such as cimetidine, ranitidine, or famotidine, resulting in poisoning. The patient's symptoms are directly attributable to the unintended ingestion of an excessive amount of this medication.

Use this code when a patient presents to an emergency department or clinic with signs and symptoms of poisoning due to an unintentional intake of an H2-receptor blocker. This typically occurs when a patient mistakenly takes too much of their prescribed medication or ingests it accidentally.

• Ensure documentation clearly states the poisoning was accidental and not intentional self-harm or assault.
• Verify this is the initial encounter for the poisoning event; subsequent encounters would use a different seventh character.
• Always code any associated signs and symptoms of the poisoning, such as central nervous system effects or cardiovascular issues.