Drug Interaction Report

Some of the medication in prilocaine topical is absorbed through the skin into the bloodstream and may cause interactions with other medications such as lidocaine topical. When used together, this combination may increase the risk of methemoglobinemia, a condition that can lead to oxygen deprivation in tissues and vital organs due to reduced oxygen-carrying capacity of the blood. Individuals may be more susceptible to developing methemoglobinemia during treatment with these medications if they are very young (especially neonates and infants) or have anemia, diseases of the heart or lungs, blood circulation disorders, liver cirrhosis, shock, sepsis, and certain genetic predispositions such as NADH cytochrome-b5 reductase deficiency, glucose-6-phosphate dehydrogenase deficiency, and hemoglobin M. In addition, excessive use of prilocaine topical such as application of large doses or on larger than recommended areas, as well as use on inflamed or abraded areas or broken skin, can increase absorption and result in high blood levels of the medication. Close medical supervision is necessary when medications that can cause methemoglobinemia are used together. Signs and symptoms of methemoglobinemia may be delayed by several hours after treatment with prilocaine topical. Patients (or their caregivers) should seek immediate medical attention if they develop a gray discoloration of the skin, mouth, or nail bed; nausea; headache; dizziness; lightheadedness; fatigue; shortness of breath; rapid or shallow breathing; a rapid heartbeat; palpitation; anxiety; or confusion. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Iron can bind to doxycycline in the gastrointestinal tract, which may prevent their absorption into the bloodstream and possibly reduce their effectiveness. To avoid or minimize the interaction, iron-containing medications and doxycycline should preferably be taken at least three to four hours apart in most cases. Talk to your doctor if you have any questions or concerns, or if you have trouble separating the dosing times. Your doctor may be able to prescribe alternatives that do not interact. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Information for this minor interaction is available on the professional version.