Injectable codeine is readily available for subcutaneous or intramuscular injection only; intravenous injection is contraindicated, as this may lead to nonimmune mast-mobile degranulation and ensuing anaphylactoid reaction. Codeine suppositories may also be marketed in a few countries. Codeine can be an opiate and an agonist on the mu opioid receptor https://www.codeingil.com/