Can I drink a grapefruit soda two hours before taking simvastatin?

Check to see if the grapefruit flavor of the soda is artificial or if it truly contains grapefruit. If it does contain real grapefruit juice then I wouldnt advise drinking it but you can double check with your Dr or better yet, your pharmacist. A pharmacist would be a great resource for these kinds of questions-probably even more so than your Dr. If the flavor is artificial then it would probably be ok to drink but again check with the pharmacist.

No. Grapefruit can increase the potency of many drugs (including simvastatin) from the normal dose up to 4 to 5 times of the dosage. The effect of the grapefruit can last up to five hours. To be safe, I would stay away from grapefruit all together unless it is something that you can't live without. If that is the case, I would talk to your doctor about when is a safe time to eat it.