Health Guide


What is it?

Magnesium is a mineral and electrolyte that is essential for life. Supplements are used to raise the amount of magnesium in the blood. It is used to treat indigestion, osteoporosis (bone loss), PMS (premenstrual syndrome), and constipation (trouble having bowel movements). Magnesium may also be used to prevent kidney stones and high blood pressure.

Other names for magnesium include: Elemental magnesium, Magnesium (mag or Mg) chloride, Mag citrate, Mag gluconate, Mag glycinate, Mag hydroxide, Mag oxide, Magnesium carbonate, Magnesium hydroxide, Magnesium oxide, Magnesium trisilicate, Milk of magnesia

Ask your doctor, nurse, or pharmacist if you need more information about this medicine or if any information in this leaflet concerns you.

Before Using:

Tell your doctor if you

  • are taking medicine or are allergic to any medicine (prescription or over-the-counter (OTC) or dietary supplement).
  • are pregnant or plan to become pregnant while using this medicine.
  • are breastfeeding.
  • have kidney disease (1).
  • have any other health problems, such as high blood pressure or heart or blood vessel disease.


Talk with your caregiver about how much magnesium you should take. The amount depends on the strength of the medicine and the reason you are taking magnesium. If you are using this medicine without instructions from your caregiver, follow the directions on the medicine bottle. Do not take more medicine or take it more often than the directions tell you to.

To store this medicine:

Keep all medicine locked up and away from children. Store medicine away from heat and direct light. Do not store your medicine in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down and not work the way it should work. Throw away medicine that is out of date or that you do not need. Never share your medicine with others.

Drug and Food Interactions:

Do not take magnesium without talking to your doctor first if you are taking:

  • Antibiotics (examples: gentamicin, tobramycin, ciprofloxacin (Cipro(R)), levofloxacin (Levaquin(R)), cefditoren (Spectracef(R)), cefpodoxime (Vantin(R)) (11,14,18,20,21.27)
  • Dasatinib (example: Sprycel(R)) (55)
  • Neuromuscular blockers (surgery drugs, examples: cisatracurium, rocuronium, vecuronium, succinylcholine) (22-26)
  • High blood pressure or heart medicines (examples: felodipine (Plendil(R)), nifedipine (Procardia(R)), diltiazem (Cardizem(R), Dilacor(R)), verapamil (Calan(R), Isoptin(R)), captopril (Capoten(R)) (16)
  • Medicine for fungus infections (examples: itraconazole (Sporanox(R)), ketoconazole (Nizoral(R), Extina(R), Xolegel(R)) (28-32)
  • Medicine for HIV infection (examples: amprenavir (Agenerase(R)), atazanavir (Reyataz(R)), tipranavir (Aptivus(R)) (33-35)
  • Medicine for osteoporosis or Paget disease (examples: ibandronate (Boniva(R)), tiludronate (Skelid(R)) (36,37)
  • Lansoprazole (Prevacid(R)) (38)
  • Sucralfate (Carafate(R)) (39)
  • Hyoscyamine (Cystospaz(R), Hyospaz(R), Levsin(R)) (40)
  • Sodium polystyrene sulfonate (Kayexalate(R), Kionex(R)) (41-44)
  • Ticlopidine (Ticlid(R)) (45)
  • Aspirin (46-52)
  • Bismuth subcitrate (Pepto Bismol(R), Kaopectate(R)) (53)
  • Labetalol (Normodyne(R), Trandate(R)) (12)
  • Levomethadyl (Orlaam(R)) (13)
  • Doxercalciferol (Hectorol(R)) (54)
  • Mycophenolate mofetil or mycophenolic acid (CellCept(R), Myfortic(R)) (17)
  • Medicine used to treat cancer (example: erlotinib (Tarceva(R)) (56)
  • Medicines used to treat low blood platelet counts (example: eltrombopag (Promacta(R)) (57)


  • Before taking magnesium, tell your doctor if you are pregnant or breastfeeding.
  • Do not use if you have severe kidney disease or heart problems (1).

Side Effects:

Call your doctor right away if you have any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hand, swelling or tingling in your mouth or throat, chest tightness, trouble breathing, or rash

Other Side Effects:

You may have the following side effects, but this medicine may also cause other side effects. Tell your doctor if you have side effects that you think are caused by this medicine.

  • Large doses may cause diarrhea (loose stools) (1)


1. Product Information: MILK OF MAGNESIA oral liquid, magnesium hydroxide oral liquid. Humco, Texarkana, TX, 2007.

2. Lima M, Cruz T, Carreiro Pousada J et al: The effect of magnesium supplementation in increasing doses on the control of type 2 diabetes. Diabetes Care 1998; 21:682-686.

3. Peikert A, Wilimzig C & Kohne-Volland R: Prophylaxis of migraine with oral magnesium: results from a prospective, multi-center, placebo-controlled and double-blind randomized study. Cephalagia 1996; 16:257-263.

4. Taubert K: Magnesium in migraine. Results of a multicenter pilot study (German). Fortschr Med 1994; 112(24):328-330.

5. Johansson G, Backman U, Danielson BG et al: Biochemical and clinical effects of the prophylactic treatment of renal calcium stones with magnesium hydroxide. J Urol 1980; 124:770-774.

6. Rude RK & Olerich M: Magnesium deficiency: possible role in osteoporosis associated with gluten-sensitive enteropathy. Osteoporosis Int 1996; 6:453-461.

7. Walker AF, De Souza MC, Vickers MF et al: Magnesium supplementation alleviates premenstrual symptoms of fluid retention. J Womens Health 1998; 7(9):1157-1165.

8. AHFS: American Society of Hospital Pharmacists Drug Information. Bethesda, MD; 1994.

9. Benitz WE & Tatro DS: The Pediatric Drug Handbook, 2nd ed. Year Book Medical Publishers, Chicago, IL; 1988.

10. L'Hommedieu CS, Nicholas D, Armes DA et al: Potentiation of magnesium sulfate induced neuromuscular weakness by gentamicin, tobramycin, and amikacin. J Pediatr 1983; 102:629-631.

11. Watson A, Coffey L, Keogh B et al: Severe hypomagnesaemia and hypocalcaemia following gentamicin therapy. Ir Med J 1983; 76:381-383.

12. Pittman J: Magnesium sulphate for pre-eclampsia and a sudden bradycardia. Br J Anaesth 2000; 85:327-328.

13. Product Information: Orlaam(R), levomethadyl. Roxane Laboratories, Inc., Columbus, Ohio, (PI revised 5/2001) reviewed 2/2002.

14. Nix DE, Watson WA, Lener ME et al: Effects of aluminum and magnesium antacids and ranitidine on the absorption of ciprofloxacin. Clin Pharmacol Ther 1989a; 46:700-705.

15. Product Information: Nimbex(R) injection, cisatracurium besylate. Glaxo Wellcome Inc, Research Triangle Park, NC; 1998.

16. Snyder SW & Capewell MS: Neuromuscular blockade with magnesium sulfate and nifedipine. Am J Obstet Gynecol 1989; 161: 35-36.

17. Product Information: CellCept(R), mycophenolate mofetil. Roche Laboratories Inc., Nutley, NJ, 1998.

18. Product Information: Cipro(R) XR, extended-release ciprofloxacin tablets. Bayer Corporation, West Haven, CT, 08/2003.

19. Product Information: Spectracef(TM), cefditoren pivoxil. TAP Pharmaceuticals, Inc., Lake Forest, Illinois, 08/2001.

20. Hughes GS, Heald DL, Barker KB et al: The effects of gastric pH and food on the pharmacokinetics of a new oral cephalosporin, cefpodoxime proxetil. Clin Pharmacol Ther 1989; 46:674-685.

21. Saathoff N, Lode H, Neider K et al: Pharmacokinetics of cefpodoxime proxetil and interactions with an antacid and an H2 receptor antagonist. Antimicrob Agents Chemother 1992; 36:796-800.

22. Product Information: Nimbex(R) injection, cisatracurium besylate. Glaxo Wellcome Inc, Research Triangle Park, NC; 1998.

23. Aldrete JA, Zahler A & Aikawa JK: Prevention of succinylcholine-induced hyperkalemia by magnesium sulfate. Can Anaesth Soc J 1970; 17:477-484.

24. Ghoneim MM & Long JP: The interaction between magnesium and other neuromuscular blocking agents. Anesthesiology 1970; 32:23.

25. Morris R & Giesecke AH: Potentiation of muscle relaxants by magnesium sulfate therapy in toxemia of pregnancy. South Med J 1968; 61:25.

26. Sinatra RS, Philip BK, Naulty JS et al: Prolonged neuromuscular blockade with vecuronium in a patient treated with magnesium sulfate. Anesth Analg 1985; 64:1220-1222.

27. Saathoff N, Lode H, Neider K et al: Pharmacokinetics of cefpodoxime proxetil and interactions with an antacid and an H2 receptor antagonist. Antimicrob Agents Chemother 1992; 36:796-800.

28. Patterson TF, Peters J, Levine SM et al: Systemic availability of itraconazole in lung transplantation. Antimicrob Agents Chemother 1996; 40:2217-2220.

29. Product Information: Sporanox(R), itraconazole. Janssen Pharmaceutica Products, L.P., Titusville, New Jersey, 02/2002.

30. Brass C, Galgiani JN, Blaschke TF et al: Disposition of ketoconazole, an oral antifungal, in humans. Antimicrob Agents Chemother 1982; 21:151-158.

31. Carlson JA, Mann HJ & Canafax DM: Effect of pH on disintegration and dissolution of ketoconazole tablets. Am J Hosp Pharm 1983; 40:1334-1336.

32. Van der Meer JWM, Keuning JJ, Scheijgrond HW et al: The influence of gastric acidity on the bioavailability of ketoconazole. J Antimicrob Chemother 1980; 6:552-554.

33. Product Information: Agenerase(R), amprenavir. Glaxo Wellcome Inc., Research Triangle Park, NC, 2000.

34. Product Information: Lexiva(TM), fosamprenavir. GlaxoSmithKline, Research Triangle Park, NC, 10/2003.

35. Baldwin JR, Borin MT, Wang Y et al: Effects of food and antacid on bioavailability of the protease inhibitor PNU-140690 in healthy volunteers (abstract). 5th Conf Retrovir Oppor Inf, Chicago, February 1-5, 1998.

36. Product Information: Boniva(TM), ibandronate sodium tablets. GlaxoSmithKline, Research Triangle Park, NC, 05/2003.

37. Product Information: Skelid(R), tiludronate. Sanofi Pharmaceuticals, Inc., New York, NY, 1998.

38. Delhotal-Landes B, Cournot A, Vermerie N et al: The effect of food and antacids on lansoprazole absorption and disposition. Eur J Drug Metab Pharmacokinet 1991; Spec No 3:315-320.

39. Product Information: Carafate(R), sucralfate. Hoechst Marion Roussel, Inc., Kansas City, MO, 1996.

40. Product Information: Levsin(R), hyoscyamine sulfate. Schwarz Pharma, Inc., Milwaukee, WI, 1996.

41. Fernandez PC & Kovnat PJ: Metabolic acidosis reversed by the combination of magnesium hydroxide and cation exchange resin. N Engl J Med 1972; 286:23.

42. Madias NE & Levey AS: Metabolic alkalosis due to absorption of "non-absorbable" antacids. Am J Med 1983; 74:155-158.

43. Schroeder ET: Alkalosis resulting from combined administration of a "non-systemic" antacid and a cation-exchange resin. Gastroenterology 1969; 56:868.

44. Ziessman HA: Alkalosis and seizure due to a cation exchange resin and magnesium hydroxide. South Med J 1976; 69:497-499.

45. Shah J, Fratis A, Ellis D et al: Effect of food and antacid on absorption of orally administered ticlopidine hydrochloride. J Clin Pharmacol 1990; 30:733-736.

46. Feldman S & Carlstedt BC: Effects of antacid on absorption of enteric-coated aspirin. JAMA 1974; 227:660.

47. Gaspari F, Vigano G, Tocatelli M et al: Influence of antacid administrations on aspirin absorption in patients with chronic renal failure on maintenance hemodialysis. Am J Kidney Dis 1988; 11:338-342.

48. Gibaldi M, Grundhofer B & Levy G: Effect of antacids on pH of urine. Clin Pharmacol Ther 1974; 16:520-525.

49. Hansten PD & Hayton WL: Effect of antacid and ascorbic acid on serum salicylate concentration. J Clin Pharmacol 1980; 20:326-331.

50. Levy G, Lampman T, Kamath BL et al: Decreased serum salicylate concentrations in children with rheumatic fever treated with antacids. N Engl J Med 1975; 293:323.

51. Shastri RA: Effect of antacids on salicylate kinetics. Int J Clin Pharmacol Ther Toxicol 1985; 23:480-484.

52. Strickland-Hodge B, Thomas TR, Gould WA et al: The effects of antacids on enteric-coated salicylate preparations. Rheumatol Rehabil 1976; 15:148-152.

53. Wagstaff AJ, Benfield P & Monk JP: Colloidal bismuth subcitrate: a review of its pharmacodynamic and pharmacokinetic properties, and its therapeutic use in peptic ulcer disease. Drugs 1988; 36:132-157.

54. Product Information: Hectorol(R), doxercalciferol. Bone Care International, Inc., Madison, WI, 2000.

55. Product Information: SPRYCEL(R) oral tablets, dasatinib oral tablets. Bristol-Myers Squibb, Princeton, NJ, 2008.

56. Product Information: TARCEVA(R) oral tablets, erlotinib oral tablets. OSI Pharmaceuticals Inc, Melville, NY, 2008.

57. Product Information: PROMACTA(R) oral tablets, eltrombopag oral tablets. Glaxo Smith Kline, Research Triangle Park,, NC, 2008.

Last Updated: 7/4/2018
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