Final answer:
For an allergic reaction to a barbiturate on the lip, stop using the drug, seek medical care, and in mild cases, antihistamines may be used, while severe reactions may require epinephrine and steroids.
Step-by-step explanation:
If an individual is experiencing an allergic reaction to a barbiturate on the lip, it is important to first cease using the medication and seek medical attention. Barbiturates, such as phenobarbital and pentobarbital, have sedative and hypnotic effects and can cause severe symptoms in the case of overdose; however, allergies involve a different response mechanism. For a mild allergic reaction, antihistamines may be prescribed to alleviate symptoms. In severe cases, emergency care involving epinephrine and/or steroids may be necessary. It is critical to inform healthcare providers about the allergy to ensure that suitable alternatives like acetaminophen, an amide found in Tylenol, can be considered for fever and pain relief without causing an allergic response.