effect and side effect ## Do you mean Difil 200? (active ingredients dyphylline and guaifenesin) If so this drug is used to treat coughing due to emphysema, asthma, and chronic bronchitis. Common side effects are: nausea, vomiting, tingly in the skin, headaches, and insomnia. To learn more about the ingredients click on the link below... Once you've linked on the link, you can choose the many different drugs that have the same ingredients. If you have any more questions or concerns please post back, and I would be happy to help.