How long does it take for anesthetic drugs to expire? The time to expiration of the drug needs to be determined by the dose of the drug and the method of administration. Local anesthetics should expire in 40-90 minutes because local anesthetics are divided into infiltrative and injectable anesthetics, and the dosage is usually determined by the size of the lesion. The expiration time of general anesthetics needs to be determined based on the duration of surgical anesthesia. The expiration time of the drugs used during anesthesia is related to the patient’s is own physical condition. Generally, after stopping the anesthetic drugs, the patient will return to normal within ten minutes to half an hour. Nowadays, anesthetic drugs are metabolized very quickly, and if the patient is obese, it may be metabolized slightly slower, but it will not take too long. The time of expiration of local anesthetic drugs also varies from person to person, so don’t worry too much, generally the anesthetic drugs will not have any effect on the body.