Drug Interactions between paricalcitol and sodium phenylbutyrate / taurursodiol

Food may affect the absorption of sodium phenylbutyrate. A high-fat, high-calorie meal (approximately 800 to 1000 calories; 500 to 600 calories from fat, 250 calories from carbohydrate, 150 calories from protein) has been shown to reduce the absorption of sodium phenylbutyrate, although it is unknown what impact this may have on the overall effectiveness of the medication. The manufacturer recommends taking sodium phenylbutyrate before a meal or snack. This is especially important if you weigh less than 70 kg (approximately 154 pounds). Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medication without first talking to your doctor.

Treatment with paricalcitol may require you to adjust your dietary intake of foods which contain natural or added calcium, phosphate (organic and inorganic), and vitamin D. Ingesting too much vitamin D or having elevated calcium and/or phosphorus levels in the blood and urine can lead to toxic effects, such as having an irregular heart rhythm, seizures, kidney stones, and eventual calcification of your blood vessels, cornea and/or the soft tissues in your body. Your doctor will monitor the levels of calcium and phosphorus in your blood during treatment with paricalcitol. Please speak with your healthcare team to determine if you require a specialized diet, particularly if you have reduced kidney function, and to discuss any other questions or concerns you have. You may require additional monitoring or a dose adjustment of paricalcitol if your diet changes. Fortified foods will state on their labeling how much calcium, phosphate, and/or vitamin D has been added. The National Institutes of Health, Office of Dietary Supplements also provides information on which foods contain calcium, phosphorus, and vitamin D. You should avoid abrupt changes in your dietary calcium intake and seek medical attention if you experience early symptoms of vitamin D intoxication such as weakness, fatigue, headache, drowsiness, vertigo, ringing in the ears, loss of appetite, nausea, vomiting, constipation, dry mouth, metallic taste, muscle pain, bone pain, muscle incoordination, and low muscle tone. Late symptoms may include frequent urination, excessive thirst, weight loss, conjunctivitis ("pink eye"), light sensitivity, runny nose, itching, increased body temperature, and irregular heart rhythm. 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.