Taking with other medications Inform your doctor or pharmacist if you are taking, have recently taken, or might take any other medicines. The test is affected by concurrent therapy with medications that can affect glucose tolerance, e.g.: nonsteroidal anti-inflammatory drugs Glucocorticoids laxative Medications to lower high blood pressure (except ACE inhibitors) Nicotinic acid derivatives Nitrazepam Phenothiazines oral contraceptives Thyroid hormones Thiazide and furosemide-type saluretics Tranquilizers and sedatives. Please note that this information may also apply to recently used medications. These medications should be discontinued at least three days before the test, if this can be done safely. If a medication cannot be discontinued, the test result requires a more nuanced interpretation.