To determine whether acute ionized hypomagnesemia and hypocalcemia immediately following
foscarnet infusions can be lessened or eliminated by prior infusion of magnesium sulfate. To
determine whether reductions in ionized magnesium, ionized calcium, and parathyroid hormone
levels following foscarnet infusions are lessened by preinfusion of magnesium sulfate. To
evaluate the safety of intravenous magnesium sulfate prior to foscarnet infusion by
monitoring blood pressure, heart rate, and heart rhythm. To characterize the effect of
magnesium sulfate on foscarnet blood levels and urinary excretion of calcium, magnesium,
phosphate, and foscarnet.
Patients are randomized to one of four treatment groups. Intravenous foscarnet is
administered for 4 days. Patients receive one of three doses of magnesium sulfate or placebo
in normal saline according to one of four schedules. Sequence of doses will differ for each
Patients must have:
- AIDS by CDC criteria.
- Documented CMV disease.
- Tolerance of foscarnet dose of 90 mg/kg bid.
- Normal serum calcium, serum creatinine, and serum phosphate.
Patients with the following symptoms or conditions are excluded:
- Known allergy to Foscarnet.
- In extremis or incapacitated because of underlying illness (e.g., comatose or
- Volume depletion.
- Nephrotoxic drugs such as IV pentamidine, amphotericin B, aminoglycosides, and
- Other investigational drugs that affect metabolic balance, such as human growth
- Oral or parenteral magnesium and calcium supplementation.
Patients with the following prior condition are excluded:
History of heart block.