Drug Interactions between guanfacine and Phanatuss

Avoid consuming grapefruit or grapefruit juice during treatment with guanFACINE, as it may increase blood levels and effects of the medication. This may cause blood pressure to fall excessively, especially when you rise from a sitting or lying position. The risk of other side effects such as drowsiness, dizziness, lightheadedness, fainting, headache, palpitations, and heart rate changes may also increase. Additionally, you should avoid or limit the use of alcohol while being treated with guanFACINE. Combining the medication with alcohol can intensify sedative and blood pressure lowering effects, which may increase the risk of falls and injury. Avoid driving or operating hazardous machinery until you know how the medication affects you, and use caution when getting up from a sitting or lying position. If you are using a long-acting or extended-release formulation of the medication, make sure you do not take it with a high-fat meal. Doing so results in increased absorption and elevated blood levels of the medication. Talk to your doctor or pharmacist if you have any questions or concerns.

Switch to professional interaction data

Alcohol can increase the nervous system side effects of dextromethorphan such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment. You should avoid or limit the use of alcohol while being treated with dextromethorphan. Do not use more than the recommended dose of dextromethorphan, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you. Talk to your doctor or pharmacist if you have any questions or concerns.

Switch to professional interaction data